[Federal Register Volume 79, Number 36 (Monday, February 24, 2014)]
[Rules and Regulations]
[Pages 10235-10293]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-03717]
[[Page 10235]]
Vol. 79
Monday,
No. 36
February 24, 2014
Part II
Department of the Interior
Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Determination of
Threatened Species Status for the Georgetown Salamander and Salado
Salamander Throughout Their Ranges; Final Rule
Federal Register / Vol. 79 , No. 36 / Monday, February 24, 2014 /
Rules and Regulations
[[Page 10236]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R2-ES-2012-0035; 4500030113]
RIN 1018-AY22
Endangered and Threatened Wildlife and Plants; Determination of
Threatened Species Status for the Georgetown Salamander and Salado
Salamander Throughout Their Ranges
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
threatened status for the Georgetown salamander (Eurycea naufragia) and
the Salado salamander (Eurycea chisholmensis) under the Endangered
Species Act of 1973 (Act), as amended. The effect of this regulation is
to conserve the two salamander species and their habitats under the
Act. This final rule implements the Federal protections provided by the
Act for these species. We are also notifying the public that, in
addition to this final listing determination, today we publish a
proposed special rule under the Act for the Georgetown salamander.
DATES: This rule becomes effective March 26, 2014.
ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and http://www.fws.gov/southwest/es/AustinTexas/.
Comments and materials received, as well as supporting documentation
used in preparing this final rule, are available for public inspection,
by appointment, during normal business hours, at U.S. Fish and Wildlife
Service, Austin Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, Field Supervisor, U.S.
Fish and Wildlife Service, Austin Ecological Services Field Office,
10711 Burnet Rd, Suite 200, Austin, TX 78758; by telephone 512-490-
0057; or by facsimile 512-490-0974. Persons who use a
telecommunications device for the deaf (TDD) may call the Federal
Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Act, a species may warrant
protection through listing if it is endangered or threatened throughout
all or a significant portion of its range. Listing a species as an
endangered or threatened species can only be completed by issuing a
rule.
This rule lists the Georgetown and Salado salamanders as threatened
species under the Act.
The basis for our action. Under the Act, we can determine that a
species is an endangered or threatened species based on any of five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) Overutilization for
commercial, recreational, scientific, or educational purposes; (C)
Disease or predation; (D) The inadequacy of existing regulatory
mechanisms; or (E) Other natural or manmade factors affecting its
continued existence. We have determined that the Georgetown and Salado
salamanders are threatened under the Act due to threats faced by the
species both now and in the future from Factors A, D, and E.
Peer review and public comment. We sought comments from independent
specialists to ensure that our designation is based on scientifically
sound data, assumptions, and analyses. We invited these peer reviewers
to comment on our listing proposal. We also considered all comments and
information received during the comment period (see Summary of Comments
and Recommendations section below).
Background
Previous Federal Action
The Georgetown salamander was included in 10 Candidate Notices of
Review:
66 FR 54808, October 30, 2001;
67 FR 40657, June 13, 2002;
69 FR 24876, May 4, 2004;
70 FR 24870, May 11, 2005;
71 FR 53756, September 12, 2006;
72 FR 69034, December 6, 2007;
73 FR 75176, December 10, 2008;
74 FR 57804, November 9, 2009;
75 FR 69222, November 10, 2010; and
76 FR 66370, October 26, 2011.
In the 2008 review, the listing priority number was lowered from 2
to 8, indicating that threats to the species were imminent, but
moderate to low in magnitude. This reduction in listing priority number
was primarily due to the land acquisition and conservation efforts of
the Williamson County Conservation Foundation. In addition, we were
petitioned by the Center for Biological Diversity to list the
Georgetown salamander as an endangered species on May 11, 2004, but at
that time, it was already a candidate species whose listing was
precluded by higher priority actions.
The Salado salamander was included in nine Candidate Notices of
Review:
67 FR 40657, June 13, 2002;
69 FR 24876, May 4, 2004;
70 FR 24870, May 11, 2005;
71 FR 53756, September 12, 2006;
72 FR 69034, December 6, 2007;
73 FR 75176, December 10, 2008;
74 FR 57804, November 9, 2009;
75 FR 69222, November 10, 2010; and
76 FR 66370, October 26, 2011.
The listing priority number has remained at 2 throughout the
reviews, indicating that threats to the species were both imminent and
high in magnitude. In addition, on May 11, 2004, the Service received a
petition from the Center for Biological Diversity to list 225 species
we previously had identified as candidates for listing in accordance
with section 4 of the Act, including the Salado salamander.
On August 22, 2012, we published a proposed rule to list as
endangered and designate critical habitat for the Austin blind
salamander (Eurycea waterlooensis), Jollyville Plateau salamander
(Eurycea tonkawae), Georgetown salamander, and Salado salamanders (77
FR 50768). That proposal had a 60-day comment period, ending October
22, 2012. We held a public meeting and hearing in Round Rock, Texas, on
September 5, 2012, and a second public meeting and hearing in Austin,
Texas, on September 6, 2012. On January 25, 2013, we reopened the
public comment period on the August 22, 2012, proposed listing and
critical habitat designation; announced the availability of a draft
economic analysis; and an amended required determinations section of
the proposal (78 FR 5385). On August 20, 2013, we extended the final
determination for the Georgetown and Salado salamanders by 6 months due
to substantial disagreement regarding: (1) The short- and long-term
population trends of these two species; (2) the interpretation of water
quality and quantity degradation information as it relates to the
status of these two species; and (3) the effectiveness of conservation
practices and regulatory mechanisms (78 FR 51129). That comment period
closed on September 19, 2013.
Since that time, the City of Georgetown, Texas, prepared and
finalized ordinances for the Georgetown salamander. All 17 of the known
Georgetown salamander locations are within the City of Georgetown's
jurisdiction for residential and commercial development. The enacted
[[Page 10237]]
ordinances were directed at alleviating threats to the Georgetown
salamander from urban development by requiring geologic assessments
prior to construction, establishing occupied site protections through
stream buffers, maintaining water quality through best management
practices, developing a water quality management plan for the City of
Georgetown, and monitoring occupied spring sites by an adaptive
management working group. In order to consider the ordinances in our
final listing determination, on January 7, 2014 (79 FR 800), we
reopened the comment period for 15 days on the proposed listing rule to
allow the public an opportunity to provide comment on the application
of the City of Georgetown's ordinances to our status determination
under section 4(a)(1) of the Act.
This rule constitutes our final determination to list the
Georgetown and Salado salamanders as threatened species.
Species Information
Taxonomy
The Georgetown and Salado salamanders are neotenic (do not
transform into a terrestrial form) members of the family
Plethodontidae. Plethodontid salamanders comprise the largest family of
salamanders within the Order Caudata, and are characterized by an
absence of lungs (Petranka 1998, pp. 157-158). The Jollyville Plateau
(Eurycea tonkawae), Georgetown, and Salado salamanders have very
similar external morphology. Because of this, they were previously
believed to be the same species; however, molecular evidence strongly
supports that there is a high level of divergence between the three
groups (Chippindale et al. 2000, pp. 15-16; Chippindale 2010, p. 2).
Morphological Characteristics
As neotenic salamanders, the Georgetown and Salado salamanders
retain external feathery gills and inhabit aquatic habitats (springs,
spring-runs, wet caves, and groundwater) throughout their lives
(Chippindale et al. 2000, p. 1). In other words, these salamanders are
aquatic and respire through gills and permeable skin (Duellman and
Trueb 1986, p. 217). Also, adult salamanders of these species are about
2 inches (in) (5 centimeters (cm)) long (Chippindale et al. 2000, pp.
32-42; Hillis et al. 2001, p. 268).
Habitat
Both species inhabit water of high quality with a narrow range of
conditions (for example, temperature, pH, and alkalinity) maintained by
groundwater from various sources. The Georgetown and Salado salamanders
depend on high-quality water in sufficient quantity and quality to meet
their life-history requirements for survival, growth, and reproduction.
Much of this water is sourced from the Northern Segment of the Edwards
Aquifer, which is a karst aquifer characterized by open chambers such
as caves, fractures, and other cavities that were formed either
directly or indirectly by dissolution of subsurface rock formations.
Water for the salamanders is provided by infiltration of surface water
through the soil or recharge features (caves, faults, fractures,
sinkholes, or other open cavities) into the Edwards Aquifer, which
discharges from springs as groundwater (Schram 1995, p. 91).
The Georgetown and Salado salamanders spend varying portions of
their life within their surface habitats (the wetted top layer of
substrate in or near spring openings and pools as well as spring runs)
and subsurface habitats (within caves or other underground areas of the
underlying groundwater source). Although surface and subsurface
habitats are often discussed separately within this final rule, it is
important to note the interconnectedness of these areas. Subsurface
habitat does not necessarily refer to an expansive cave underground.
Rather, it may be described as the water-filled rock matrix below the
stream bed. As such, subsurface habitats are impacted by the same
threats that impact surface habitat, as the two exist as a continuum
(Bendik 2012, City of Austin (COA), pers. comm.).
Salamanders move an unknown depth into interstitial spaces (empty
voids between rocks) within the spring or streambed substrate that
provide foraging habitat and protection from predators and drought
conditions (Cole 1995, p. 24; Pierce and Wall 2011, pp. 16-17). They
may also use deeper passages of the aquifer that connect to the spring
opening (Dries 2011, COA, pers. comm.). This behavior makes it
difficult to accurately estimate population sizes, as only salamanders
on the surface can be regularly monitored. However, techniques have
been developed for marking individual salamanders, which allows for
better estimating population numbers using ``mark and recapture'' data
analysis techniques. These techniques have been used by the COA on the
Jollyville Plateau salamander (Bendik et al. 2013, pp. 2-7) and by Dr.
Benjamin Pierce at Southwestern University on the Georgetown salamander
(Pierce 2011, pp. 5-7).
Range
The habitats of the Georgetown and Salado salamanders occur in the
Northern Segment of the Edwards Aquifer. The recharge and contributing
zones of this segment of the Edwards Aquifer are found in portions of
Travis, Williamson, and Bell Counties, Texas (Jones 2003, p. 3).
Diet
Although we are unaware of detailed dietary studies for Georgetown
and Salado salamanders, their diets are presumed to be similar to other
Eurycea species, which consist of small aquatic invertebrates such as
amphipods, copepods, isopods, and insect larvae (COA 2001, pp. 5-6). A
stomach content analysis by the City of Austin demonstrated that the
Jollyville Plateau salamander preys on varying proportions of aquatic
invertebrates, such as ostracods, copepods, mayfly larvae, fly larvae,
snails, water mites, aquatic beetles, and stone fly larvae, depending
on the location of the site (Bendik 2011b, pers. comm.). The feces of
one wild-caught Austin blind salamander (Eurycea waterlooensis)
contained amphipods, ostracods, copepods, and plant material (Hillis et
al. 2001, p. 273). Gillespie (2013, pp. 5-9) also found that the diet
of the closely related Barton Springs salamanders (Eurycea sosorum)
consisted primarily of planarians or chironomids (flatworms or
nonbiting midge flies), depending on which was more abundant, and
amphipods (when planarians and chironomids were rare).
Predation
The Georgetown and Salado salamanders share similar predators,
which include centrarchid fish (carnivorous freshwater fish belonging
to the sunfish family), crayfish (Cambarus sp.), and large aquatic
insects (Cole 1995, p. 26; Bowles et al. 2006, p. 117; Pierce and Wall
2011, pp. 18-20).
Reproduction
The detection of juveniles in all seasons suggests that
reproduction occurs year-round (Bendik 2011a, p. 26; Hillis et al.
2001, p. 273). However, juvenile abundance of Georgetown salamanders
typically increases in spring and summer, indicating that there may be
relatively more reproduction occurring in winter and early spring
compared to other seasons (Pierce 2012, pp. 10-11, 18, 20). In
addition, most gravid (egg-bearing) females of the Georgetown
salamander are found from October through April (Pierce 2012, p. 8;
Pierce and McEntire
[[Page 10238]]
2013, p. 6). Because eggs are very rarely found on the surface, these
salamanders likely deposit their eggs underground for protection
(O'Donnell et al. 2005, p. 18).
Population Connectivity
More study is needed to determine the nature and extent of the
dispersal capabilities of the Georgetown and Salado salamanders. It has
been suggested that they may be able to travel some distance through
subsurface aquifer conduits. For example, it has been thought that
Austin blind salamander can occur underground throughout the entire
Barton Springs complex (Dries 2011, COA, pers. comm.). The spring
habitats used by salamanders of the Barton Springs complex are not
connected on the surface, so the Austin blind salamander population
could extend a horizontal distance of at least 984 feet (ft) (300
meters (m)) underground, as this is the approximate distance between
the farthest two outlets within the Barton Springs complex known to be
occupied by the species. However, a mark-and-recapture study failed to
document the movement of endangered Barton Springs salamanders (Eurycea
sosorum) between any of the springs in the Barton Springs complex
(Dries 2012, COA, pers. comm.). This finding could indicate that
individual salamanders are not moving the distances between spring
openings. Alternatively, this finding could mean that the study simply
failed to capture the movement of salamanders. This study has only
recently begun and is relatively small in scope.
Due to the similar life history of the Austin blind salamander to
the Georgetown and Salado salamanders, it is plausible that populations
of these latter two species could also extend 984 ft (300 m) through
subterranean habitat, assuming the Austin blind salamander is capable
of moving between springs in the Barton Springs complex. However,
subsurface movement is likely to be limited by the highly dissected
nature of the aquifer system, where spring sites can be separated from
other spring sites by large canyons or other physical barriers to
movement. Surface movement is similarly inhibited by geologic,
hydrologic, physical, and biological barriers (for example, predatory
fish commonly found in impoundments along urbanized tributaries (Bendik
2012, COA, pers. comm.). Dye-trace studies have demonstrated that some
Jollyville Plateau salamander sites located 2.9 miles (mi) (4.7
kilometers (km)) apart are connected hydrologically (Whitewater Cave to
R-Bar-B Spring and Hideaway Cave to R-Bar-B Spring) (Hauwert and Warton
1997, pp. 12-13), but it remains unclear if salamanders are travelling
between those sites. Also, in Salado, a large underground conduit that
conveys groundwater from the area under the Stagecoach Hotel to Big
Boiling Spring is large enough to support salamander movement (Texas
Parks and Wildlife Department [TPWD] 2011a, pers. comm.; Mahler 2012,
U.S. Geological Survey [USGS], pers. comm.; Yelderman Jr. et al. 2013,
p. 1). In conclusion, some data indicate that some populations could be
connected through subterranean water-filled spaces. However, we are
unaware of any information available on the frequency of movements and
the actual nature of connectivity among populations.
Population Persistence
A population's persistence (ability to survive and avoid
extirpation) is influenced by a population's demographic factors (such
as survival and reproductive rates) as well as its environment. The
population needs of the Georgetown and Salado salamanders are the
factors that provide for a high probability of population persistence
over the long term at a given site (for example, low degree of threats
and high survival and reproduction rates). We are unaware of detailed
studies that describe all of the demographic factors that could affect
the population persistence of the Georgetown and Salado salamanders;
however, we have assessed their probability of persistence by
evaluating environmental factors (threats to their surface habitats)
and using the available information we know about the number of
salamanders that occur at each site.
To estimate the probability of persistence of each population
involves considering the predictable responses of the population to
various environmental factors (such as the amount of food available or
the presence of a toxic substance), as well as the stochasticity.
Stochasticity refers to the random, chance, or probabilistic nature of
the demographic and environmental processes (Van Dyke 2008, pp. 217-
218). Generally, the larger the population, the more likely it is to
survive stochastic events in both demographic and environmental factors
(Van Dyke 2008, p. 217). Conversely, the smaller the population, the
higher its chances are of extirpation when experiencing this
demographic and environmental stochasticity.
Rangewide Needs
We used the conservation principles of redundancy, representation,
and resiliency (Shaffer and Stein 2000, pp. 307, 309-310) to better
inform our view of what contributes to these species' probability of
persistence and how best to conserve them. ``Resiliency'' is the
ability of a species to persist through severe hardships or stochastic
events (Tear et al. 2005, p. 841). ``Redundancy'' means a sufficient
number of populations to provide a margin of safety to reduce the risk
of losing a species or certain representation (variation) within a
species, particularly from catastrophic or other events.
``Representation'' means conserving ``some of everything'' with regard
to genetic and ecological diversity to allow for future adaptation and
maintenance of evolutionary potential. Representation can be measured
through the breadth of genetic diversity within and among populations
and ecological diversity (also called environmental variation or
diversity) occupied by populations across the species range.
A variety of factors contribute to a species' resiliency. These can
include how sensitive the species is to disturbances or stressors in
its environment, how often they reproduce and how many young they have,
how specific or narrow their habitat needs are. A species' resiliency
can also be affected by the resiliency of individual populations and
the number of populations and their distribution across the landscape.
Protecting multiple populations and variation of a species across its
range may contribute to its resiliency, especially if some populations
or habitats are more susceptible or better adapted to certain threats
than others (Service and NOAA 2011, p. 76994). The ability of
individuals from populations to disperse and recolonize an area that
has been extirpated may also influence their resiliency. As population
size and habitat quality increase, the population's ability to persist
through periodic hardships also increases.
A minimal level of redundancy is essential for long-term viability
(Shaffer and Stein 2000, pp. 307, 309-310; Groves et al. 2002, p. 506).
This provides a margin of safety for a species to withstand
catastrophic events (Service and NOAA 2011, p. 76994) by decreasing the
chance of any one event affecting the entire species.
Representation and the adaptive capabilities (Service and NOAA
2011, p. 76994) of both the Georgetown and Salado salamanders are also
important
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for long-term viability. Because a species' genetic makeup is shaped
through natural selection by the environments it has experienced
(Shaffer and Stein 2000, p. 308), populations should be protected in
the array of different environments in which the salamanders occur
(surface and subsurface) as a strategy to ensure genetic
representation, adaptive capability, and conservation of the species.
To increase the probability of persistence of each species,
populations of the Georgetown and Salado salamanders should be
conserved in a manner that ensures their variation and representation.
This result can be achieved by conserving salamander populations in a
diversity of environments (throughout their ranges), including: (1)
Both spring and cave locations, (2) habitats with groundwater sources
from various aquifers and geologic formations, and (3) at sites with
different hydrogeological characteristics, including sites where water
flows come from artesian pressure, a perched aquifer, or resurgence
through alluvial deposits.
Information for each of the salamander species is discussed in more
detail below.
Georgetown Salamander
The Georgetown salamander is characterized by a broad, relatively
short head with three pairs of bright-red gills on each side behind the
jaws, a rounded and short snout, and large eyes with a gold iris. The
upper body is generally grayish with varying patterns of melanophores
(cells containing brown or black pigments called melanin) and
iridophores (cells filled with iridescent pigments called guanine),
while the underside is pale and translucent. The tail tends to be long
with poorly developed dorsal and ventral fins that are golden-yellow at
the base, cream-colored to translucent toward the outer margin, and
mottled with melanophores and iridophores. Unlike the closely related
Jollyville Plateau salamander, the Georgetown salamander has a distinct
dark border along the lateral margins of the tail fin (Chippindale et
al. 2000, p. 38). As with the Jollyville Plateau salamander, the
Georgetown salamander has recently discovered cave-adapted forms with
reduced eyes and pale coloration (TPWD 2011, p. 8).
The Georgetown salamander is known from springs along five
tributaries (South, Middle, and North Forks; Cowan Creek; and Berry
Creek) to the San Gabriel River (Pierce 2011a, p. 2) and from two caves
(aquatic, subterranean locations) in Williamson County, Texas. A
groundwater divide between the South Fork of the San Gabriel River and
Brushy Creek to the south likely creates the division between the
ranges of the Jollyville Plateau and Georgetown salamanders (Williamson
County 2008, p. 3-34).
The Service is currently aware of 17 Georgetown salamander
localities (15 in or around a spring opening and 2 in caves). We have
recently received confirmation that Georgetown salamanders occur at two
additional spring sites (Hogg Hollow II Spring and Garey Ranch Spring)
(Covey 2013, pers. comm., Covey 2014, pers. comm.) This species has not
been observed in more than 20 years at San Gabriel Spring and more than
10 years at Buford Hollow Spring, despite several survey efforts to
find it (Chippindale et al. 2000, p. 40, Pierce 2011b, c, Southwestern
University, pers. comm.). We are unaware of any population surveys in
the last 10 years from a number of sites (such as Cedar Breaks Hiking
Trail, Shadow Canyon, and Bat Well). Georgetown salamanders continue to
be observed at the remaining 12 sites (Avant Spring, Swinbank Spring,
Knight Spring, Twin Springs, Cowan Creek Spring, Cedar Hollow Spring,
Cobbs Spring/Cobbs Well, Garey Ranch Spring, Hogg Hollow Spring, Hogg
Hollow II Spring, Walnut Spring, and Water Tank Cave) (Pierce 2011c,
pers. comm.; Gluesenkamp 2011a, TPWD, pers. comm.).
Recent mark-recapture studies suggest a population size of 100 to
200 adult salamanders at Twin Springs, with a similar population
estimate at Swinbank Spring (Pierce 2011a, p. 18). Population sizes at
other sites are unknown, but visual surface counts result in low
numbers (Williamson County 2008, pp. 3-35). In fact, through a review
of survey data available in our files and provided during the peer
review and public comment period for the proposed rule, we found that
the highest numbers observed at each of the other spring sites during
the last 10 years is less than 50 (less than 5 salamanders at Avant
Spring, Bat Well Cave, Cobbs Spring/CobbsWell, Shadow Canyon, and
Walnut Spring; 0 salamanders at Buford Hollow Spring and San Gabriel
Spring). There are other springs in Williamson County that may support
Georgetown salamander populations, but access to the private lands
where these springs are found has not been allowed, which has prevented
surveys being done at these sites (Williamson County 2008, pp. 3-35).
Surface-dwelling Georgetown salamanders inhabit spring runs,
riffles, and pools with gravel and cobble rock substrates (Pierce et
al. 2010, pp. 295-296). This species prefers larger cobble and boulders
to use as cover (Pierce et al. 2010, p. 295). Georgetown salamanders
are found within 164 ft (50 m) of a spring opening (Pierce et al.
2011a, p. 4), but they are most abundant within the first 16.4 ft (5 m)
(Pierce et al. 2010, p. 294). However, Jollyville Plateau salamanders,
a closely related species, have been found farther from a spring
opening in the Bull Creek drainage. A recent study using mark-recapture
methods found marked individuals moved up to 262 ft (80 m) both
upstream and downstream from the Lanier Spring outlet (Bendik 2013,
pers. comm.). This study demonstrates that Eurycea salamanders in
central Texas can travel greater distances from a discrete spring
opening than previously thought, including upstream areas, if suitable
habitat is present.
The water chemistry of Georgetown salamander habitat is constant
year-round in terms of temperature and dissolved oxygen (Pierce et al.
2010, p. 294, Biagas et al. 2012, p. 163). Although some reproduction
occurs year-round, recent data indicate that Georgetown salamanders
breed mostly in winter and early spring (Pierce 2012, p. 8; Pierce and
McEntire 2013, p. 6). The cave sites (Bat Well and Water Tank Cave) and
the subterranean portion of Cobbs Well where this species is known to
occur have been less studied than its surface habitat; therefore, the
quality and extent of their subterranean habitats are not well
understood.
Salado Salamander
The Salado salamander has reduced eyes compared to other spring-
dwelling Eurycea species in north-central Texas and lacks well-defined
melanophores (pigment cells that contain melanin). It has a relatively
long and flat head, and a blunt and rounded snout. The upper body is
generally grayish-brown with a slight cinnamon tinge and an irregular
pattern of tiny, light flecks. The underside is pale and translucent.
The end portion of the tail generally has a well-developed fin on top,
but the bottom tail fin is weakly developed (Chippindale et al. 2000,
p. 42).
The Salado salamander is known historically from four spring sites
near the village of Salado, Bell County, Texas: Big Boiling Springs
(also known as Main, Salado, or Siren Springs), Lil' Bubbly Springs,
Lazy Days Fish Farm Springs (also known as Critchfield Springs), and
Robertson Springs (Chippindale et al. 2000, p. 43; TPWD 2011, pp. 1-2).
These springs bubble up through faults in the Northern Segment
[[Page 10240]]
of the Edwards Aquifer and associated limestone along Salado Creek
(Brune 1975, p. 31). The four spring sites all contribute to Salado
Creek. Under Brune's (1975, p. 5) definition, which identifies springs
depending on flow, all sites are considered small (4.5 to 45 gallons
per minute [17 to 170 liters per minute]) to medium springs (45 to 449
gallons per minute [170 to 1,1700 liters per minute]). Two other spring
sites (Benedict and Anderson Springs) are located downstream from Big
Boiling Springs and Robertson Springs. These springs have been surveyed
by TPWD periodically since June 2009, but no salamanders have been
found (Gluesenkamp 2010, TPWD, pers. comm.). In August 2009, TPWD
discovered a population of salamanders at a new site (Solana Spring
1) farther upstream on Salado Creek in Bell County, Texas
(TPWD 2011, p. 2). Salado salamanders were recently confirmed at two
additional spring sites (Cistern and Hog Hollow Springs) on the Salado
Creek in March 2010 (TPWD 2011, p. 2). In total, the Salado salamander
is currently known from seven springs. A groundwater divide between
Salado Creek and Berry Creek to the south likely creates a division
between the ranges of the Georgetown and Salado salamander (Williamson
County 2008, p. 3-34).
Of the two salamander species, Salado salamanders have been
observed the least. Biologists were unable to observe this species in
its type locality (location from which a specimen was first collected
and identified as a species) despite over 20 visits to Big Boiling
Springs that occurred between 1991 and 1998 (Chippindale et al. 2000,
p. 43). Likewise, TPWD surveyed this site weekly from June 2009 until
May 2010, and found one salamander (Gluesenkamp 2010, TPWD, pers.
comm.) at a spring outlet locally referred to as ``Lil' Bubbly''
located near Big Boiling Springs. One additional unconfirmed sighting
of a Salado salamander in Big Boiling Springs was reported in 2008, by
a citizen of Salado, Texas. In 2009, TPWD was granted access to
Robertson Springs to survey for the Salado salamander. This species was
reconfirmed at this location in February 2010 (Gluesenkamp 2010, TPWD,
pers. comm.). In the fall of 2012, all of the spring outlets near the
Village of Salado were thoroughly searched over a period of two months
using a variety of sampling methods, and no Salado salamanders were
found (Hibbitts 2013, p. 2). Salado salamander populations appear to be
larger at spring sites upstream of the Village of Salado, probably due
to the higher quality of the habitat (Gluesenkamp 2011b, TPWD, pers.
comm.).
Summary of Comments and Recommendations
We requested comments from the public on the proposed listing for
Georgetown salamander and Salado salamander during three comment
periods. The first comment period associated with the publication of
the proposed rule (77 FR 50768) opened on August 22, 2012, and closed
on October 22, 2012, during which we held public meetings and hearings
on September 5 and 6, 2012, in Round Rock and Austin, Texas,
respectively. We reopened the comment period on the proposed listing
rule from January 25, 2013, to March 11, 2013 (78 FR 5385). During our
6-month extension on the final determination for the Georgetown and
Salado salamanders, we reopened the comment period from August 20,
2013, to September 19, 2013 (78 FR 51129). On January 7, 2014, we
reopened the comment period and announced the availability of the City
of Georgetown's final ordinance for water quality and urban development
(79 FR 800). We reopened the comment period to allow all interested
parties an opportunity to comment simultaneously on the proposed rule
and the effect of the new city ordinance on the threats to the species.
That comment period closed on January 22, 2014. We also contacted
appropriate Federal, state, and local agencies; scientific
organizations; and other interested parties and invited them to comment
on the proposed rule during these comment periods.
We received a total of approximately 483 comments during the open
comment periods for the proposed listing and critical habitat rules.
All substantive information provided during the comment periods has
been incorporated directly into the final listing rule for the
salamanders and is addressed below in our response to comments.
Comments from peer reviewers and state agencies are grouped separately
below. Comments received are grouped into general issues specifically
relating to the proposed listing for the salamander species. Beyond the
comments addressed below, several commenters submitted additional
reports and references for our consideration, which were reviewed and
incorporated into this final listing rule as appropriate.
Peer Review
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinions from 22 knowledgeable
individuals with scientific expertise concerning the hydrology,
taxonomy, and ecology that is important to these salamander species. We
requested expert opinions from taxonomists specifically to review the
proposed rule in light of an unpublished report by Forstner (2012,
entire) that questioned the taxonomic validity of the four central
Texas salamanders as separate species. We received responses from 13 of
the peer reviewers.
During the first comment period, we received some contradictory
public comments, and we also found new information relative to the
listing determination. For these reasons, we conducted a second peer
review on: (1) Salamander demographics and (2) urban development and
stream habitat. During this second peer review, we solicited expert
opinions from 20 knowledgeable individuals with expertise in the two
areas identified above. We received responses from eight peer reviewers
during this second review. The peer reviewers generally concurred with
our methods and conclusions and provided additional information,
clarifications, and suggestions to improve the final listing and
critical habitat rule. Peer reviewer comments are addressed in the
following summary and incorporated into the final rule as appropriate.
Peer Reviewer Comments
Taxonomy
(1) Comment: Most peer reviewers stated that the best available
scientific information was used to develop the proposed rule and the
Service's analysis of the available information was scientifically
sound. Further, most reviewers stated that our assessment that these
are four distinct species and our interpretation of literature
addressing threats (including reduced habitat quality due to
urbanization and increased impervious cover) to these species was well
researched. However, some researchers suggested that further research
would strengthen or refine our understanding of these salamanders. For
example, one reviewer stated that the Jollyville Plateau salamander
taxonomy was supported by weak but suggestive evidence, and therefore,
it needed more study. Another reviewer thought there was evidence of
missing descendants in the group that included the Jollyville Plateau
and Georgetown salamanders in the enzyme analysis presented in the
original species descriptions (Chippindale et al. 2000, entire).
Our Response: Peer reviewers' comments indicate that we used the
best available science, and we correctly
[[Page 10241]]
interpreted that science as recognizing the central Texas salamanders
as four separate species. In the final listing rule, we continue to
recognize the Austin blind, Jollyville Plateau, Georgetown, and Salado
salamanders as four distinct and valid species. However, we acknowledge
that the understanding of the taxonomy of these salamander species can
be strengthened by further research.
(2) Comment: Forstner (2012, pp. 3-4) used the size of geographic
distributions as part of his argument for the existence of fewer
species of Eurycea in Texas than are currently recognized. Several peer
reviewers commented that they saw no reason for viewing the large
number of Eurycea species with small distributions in Texas as
problematic when compared to the larger distributions of Eurycea
species outside of Texas. They stated that larger numbers and smaller
distributions of Texas Eurycea species are to be expected given the
isolated spring environments that they inhabit within an arid
landscape. Salamander species with very small ranges are common in
several families and are usually restricted to island, mountain, or
cave habitats.
Our Response: See our response to comment 1.
(3) Comment: Forstner (2012, pp. 15-16) used results from Harlan
and Zigler (2009), indicating that levels of genetic variation within
the eastern species the spotted-tail salamander (E. lucifuga) are
similar to those among six currently recognized species of Texas
Eurycea, as part of his argument that there are fewer species in Texas
than currently recognized. Several peer reviewers said that these sorts
of comparisons can be very misleading in that they fail to take into
consideration differences in the ages, effective population sizes, or
population structure of the units being compared. The delineation of
species should be based on patterns of genetic variation that influence
the separation (or lack thereof) of gene pools rather than solely on
the magnitude of genetic differences, which can vary widely within and
between species groups.
Our Response: See our response to comment 1.
(4) Comment: Several peer reviewers stated that the taxonomic tree
presented in Forstner (2012, pp. 20, 26) is difficult to evaluate
because of the following reasons: (1) No locality information is given
for the specimens; (2) it disagrees with all trees in other studies
(which seem to be largely congruent with one another), including that
in Forstner and McHenry (2010, pp. 13-16) with regard to monophyly (a
group in which the members are comprised of all of the descendants from
a common ancestor) of several of the currently recognized species; and
(3) the tree is only a gene tree, presenting sequence data on a single
gene, which provides little or no new information on species
relationships of populations.
Our Response: See our response to comment 1.
(5) Comment: Peer reviewers generally stated that Forstner (2012,
pp. 13-14) incorrectly dismisses morphological data that have been used
to recognize some of the Texas Eurycea species on the basis that it is
prone to convergence (acquisition of the same biological trait in
unrelated lineages) and, therefore, misleading. The peer reviewers
commented that it is true that similarities in characters associated
with cave-dwelling salamanders can be misleading when suggesting that
the species possessing those characters are closely related. However,
this in no way indicates that the reverse is true; that is, indicating
differences in characters is not misleading in identifying separate
species.
Our Response: See our response to comment 1.
Impervious Cover
(6) Comment: The 10 percent impervious cover threshold may not be
protective of salamander habitat based on a study by Coles et al.
(2012, pp. 4-5), which found a loss of sensitive species due to
urbanization and that there was no evidence of a resistance threshold
to invertebrates that the salamanders prey upon. A vast amount of
literature indicates that 1 to 2 percent impervious cover can cause
habitat degradation, and, therefore, the 10 percent threshold for
impervious cover will not be protective of these species.
Our Response: We recognize that low levels of impervious cover in a
watershed may have impacts on aquatic life, and we have incorporated
results of these studies into the final listing rule. However, we are
aware of only one peer-reviewed study that examined watershed
impervious cover effects on salamanders in central Texas, and this
study found impacts on salamander density in watersheds with over 10
percent impervious cover (Bowles et al. 2006, pp. 113, 117-118).
Because this impervious cover study was done locally, we are using 10
percent as a current reference point to categorize watersheds that are
impacted in terms of salamander density.
(7) Comment: While the Service's impervious cover analysis assessed
impacts on stream flows and surface habitat, it neglected to address
impacts over the entire recharge zone of the contributing aquifers on
spring flows in salamander habitat. Also, the surface watersheds
analyzed in the proposed rule are irrelevant because these salamanders
live in cave streams and spring flows that receive groundwater. Without
information on the groundwater recharge areas, the rule should be clear
that the surface watersheds are only an approximation of what is
impacting the subsurface drainage basins.
Our Response: We acknowledge that the impervious cover analysis is
limited to impacts on the surface watershed. Because the specific
groundwater recharge areas of individual springs are unknown, we cannot
accurately assess the current or future impacts on these areas.
However, we recognize subsurface flows as another avenue for
contaminants to reach the salamander sites, and we tried to make this
clearer in the final rule.
(8) Comment: Several of the watersheds analyzed for impervious
cover in the proposed rule were overestimated. The sub-basins in these
larger watersheds need to be analyzed for impervious cover impacts.
Our Response: We have refined our impervious cover analysis in this
final listing rule to clarify the surface watersheds of individual
spring sites. Our final impervious cover report containing this refined
analysis is available on the Internet at http://www.regulations.gov
under Docket No. FWS-R2-ES-2012-0035 and at http://www.fws.gov/southwest/es/AustinTexas/.
Threats
(9) Comment: One peer reviewer stated that the threat to these
species from over collection for scientific purposes may be
understated.
Our Response: We have reevaluated the potential threat of
overutilization for scientific purposes and have incorporated a
discussion of this under Factor B ``Overutilization for Commercial,
Recreational, Scientific, or Educational Purposes.'' We recognize that
removing individuals from small, localized populations in the wild
without any proposed plans or regulations to restrict these activities
could increase the population's vulnerability of extinction and
decrease its resiliency and ability to withstand stochastic events.
However, we do not consider overutilization from collecting salamanders
in the wild to be substantial enough to be a threat by itself; however,
it may cause population declines and could negatively impact
[[Page 10242]]
both salamander species in combination with other threats.
Salamander Demographics
(10) Comment: Several peer reviewers agreed that COA's salamander
survey data were generally collected and analyzed appropriately and
that the results are consistent with the literature on aquatic species'
responses to urbanizing watersheds. Three reviewers had some
suggestions on how the data analysis could be improved, but they also
state that COA's analysis is the best scientific data available, and
alternative methods of analysis would not likely change the
conclusions.
Our Response: Because the peer reviewers examined COA's salamander
demographic data, as well as SWCA Environmental Consultants' analysis
of the COA's data, and generally agreed that the COA's data was the
best information available, we continue to rely upon this data set in
the final listing rule.
(11) Comment: Two peer reviewers pointed out that water samples
were collected by SWCA during a period of very low rainfall and,
therefore, under represent the contribution of water influenced by
urban land cover. The single sampling effort of water and sediment at
the eight sites referenced in the SWCA report do not compare in scope
and magnitude to the extensive studies referenced from the COA. The
numerous studies conducted (and referenced) within the known ranges of
the salamander species provide scientific support at the appropriate
scale for recent and potential habitat degradation due to urbanization.
One peer reviewer pointed out that if you sort the spring sites SWCA
sampled into ``urbanized'' and ``rural'' categories, the urban sites
generally have more degraded water quality than the rural sites, in
terms of nitrate, nitrite, Escherichia coli (E. coli) counts, and fecal
coliform bacteria counts.
Our Response: The peer reviewers made valid arguments that the SWCA
(2012, pp. 21-24) did not present convincing evidence that overall
water quality at salamander sites in Williamson County is good or that
urbanization is not impacting the water quality at these sites. Water
quality monitoring based on one or a few samples is not necessarily
reflective of conditions at the site under all circumstances that the
salamanders are exposed to over time. Based on this assessment, we
continued to rely upon the best scientific information available in
published literature that indicate water quality will decline as
urbanization within the watershed increases.
(12) Comment: The SWCA report indicates that increasing
conductivity is related to drought. (Note: Conductivity is a measure of
the ability of water to carry an electrical current and can be used to
approximate the concentration of dissolved inorganic solids in water
that can alter the internal water balance in aquatic organisms,
affecting the salamanders' survival. Conductivity levels in the Edwards
Aquifer are naturally low. As ion concentrations such as chlorides,
sodium, sulfates, and nitrates rise, conductivity will increase. The
stability of the measured ions makes conductivity an excellent
monitoring tool for assessing the impacts of urbanization to overall
water quality. High conductivity has been associated with declining
salamander abundance.). While SWCA's report notes lack of rainfall as
the dominant factor in increased conductivity, the confounding
influence of decreases in infiltration and increases in sources of ions
as factors associated with urbanization and changes in water quality in
these areas is not addressed by SWCA. Higher conductivity in urban
streams is well documented and was a major finding of the U.S.
Geological Survey (USGS) urban land use studies (Coles et al. 2012).
Stream conductivity increased with increasing urban land cover in every
metropolitan area studied.
Our Response: While drought may result in increased conductivity,
increased conductivity is also a reflection of increased urbanization.
We incorporated information from the study by Coles et al. (2012) in
the final listing rule, and we continue to include conductivity as a
measure of water quality.
(13) Comment: One peer reviewer stated that SWCA's criticisms of
COA's linear regression analysis, general additive model, and
population age structure were not relevant and were unsupported. In
addition, peer reviewers agreed that COA's mark-recapture estimates are
robust and highly likely to be correct. Three peer reviewers agreed
that SWCA misrepresented the findings of Luo (2010) and stated that
this thesis does not invalidate the findings of COA.
Our Response: Because the peer reviewers examined COA's data, as
well as SWCA's analysis of the COA's data, and generally agreed that
the COA's data was the best information available, we continue to rely
upon this data set in the final listing rule.
(14) Comment: One peer reviewer stated that the long-term data
collected by the COA on the Jollyville Plateau salamander were simple
counts that serve as indices of relative population abundance and are
not a measure of absolute abundance. This data assumes that the
probability of observing salamanders remains constant over time,
season, and among different observers. This assumption is often
violated, which results in unknown repercussions on the assessment of
population trends. Therefore, the negative trend observed in several
sites could be due to a real decrease in population absolute abundance,
but could also be related to a decrease in capture probabilities over
time (or due to an interaction between these two factors). Absolute
population abundance and capture probabilities should be estimated in
urban sites using the same methods implemented at rural sites by COA.
However, even in the absence of clear evidence of local population
declines of Jollyville Plateau salamanders, the proposed rule was
correct in its assessment because there is objective evidence that
urbanization negatively impacts the density of Eurycea salamanders (for
example, Barrett et al. 2010).
Our Response: We recognize that the long-term survey data of
Jollyville Plateau salamanders using simple counts may not give
conclusive evidence on the true population status at each site.
However, based on the threats and evidence from scientifically peer-
reviewed literature, we conclude that the declines in counts seen at
urban Jollyville Plateau salamander sites represent the best available
information on the status of the Jollyville Plateau salamander and are
likely representative of real declines in the population. We expect
similar responses by Georgetown and Salado salamanders.
(15) Comment: One peer reviewer had similar comments on COA
salamander counts and relating them to populations. They stated that
the conclusion of a difference in salamander counts between sites with
high and low levels of impervious cover is reasonable based on COA's
data. However, this conclusion is not about salamander populations, but
instead about the counts. The COA's capture-mark-recapture analyses
provide strong evidence of both non-detection and substantial temporary
emigration, findings consistent with other studies of salamanders in
the same family as the Jollyville Plateau salamander. This evidence
cautions against any sort of analysis that relies on raw count data to
draw inferences about populations.
Our Response: See our response to the previous comment.
[[Page 10243]]
(16) Comment: The SWCA (2012, pp. 70-76) argues that declines in
salamander counts can be attributed to declines in rainfall during the
survey period and not watershed urbanization. However, one peer
reviewer stated that SWCA provided no statistical analysis to validate
this claim and misinterpreted the conclusions of Gillespie (2011) to
support their argument. A second peer reviewer agrees that counts of
salamanders are related to natural wet and dry cycles but points out
that COA has taken this effect into account in their analyses. Another
peer reviewer points out that this argument contradicts SWCA's (2012)
earlier claim that COA's salamander counts are unreliable data. If the
data were unreliable, they probably would not correlate to
environmental changes.
Our Response: Although rainfall is undoubtedly important to these
strictly aquatic salamander species, the best scientific information
suggests that rainfall is not the only factor driving salamander
population fluctuations. In the final listing rule, we continue to rely
upon this evidence as the best scientific and commercial information
available, which suggests that urbanization is also a large factor
influencing declines in salamander counts.
Regarding comments from SWCA on the assessment of threats, peer
reviewers made the following comments:
(17) Comment: SWCA's (2012, pp. 84-85) summary understates what is
known about the ecology of Eurycea species and makes too strong of a
conclusion about the apparent ``coexistence with long-standing human
development.'' Human development and urbanization is an incredibly
recent stressor in the evolutionary history of the central Texas
Eurycea, and SWCA's assertion that the Eurycea will be ``hardy and
resilient'' to these new stressors is not substantiated with any
evidence. In direct contradiction to this assertion, SWCA (2012, p. 83)
explains how one population of Georgetown salamanders was extirpated
due to municipal groundwater pumping drying the spring.
(18) Comment: SWCA (2012, p. 7) states that, ``Small population
size and restricted distribution are not among the five listing
criteria and do not of themselves constitute a reason for considering a
species at risk of extinction.'' To the contrary, even though the
salamanders may naturally occur in small isolated populations, small
isolated populations and the inability to disperse between springs
should be considered under listing criteria E as a natural factor
affecting the species' continued existence. In direct contradiction,
SWCA (2012, p. 81) later states that, ``limited dispersal ability
(within a spring) may increase the species' vulnerability as
salamanders may not move from one part of the spring run to another
when localized habitat loss or degradation occurs.'' It is well known
that small population size and restricted distributions make
populations more susceptible to selection or extinction due to
stochastic events. Small population size can also affect population
density thresholds required for successful mating.
(19) Comment: SWCA (2012, p. v) argues that the Jollyville Plateau
salamander is not in immediate danger of extinction because, ``over 60
of the 90-plus known Jollyville Plateau salamander sites are
permanently protected within preserve areas, and 4 of the 16 known
Georgetown salamander sites are permanently protected (and
establishment of additional protected sites is being considered).''
This statement completely ignores the entire aquifer recharge zone,
which is not included in critical habitat. Furthermore, analysis of the
COA's monitoring and water quality datasets clearly demonstrate that,
even within protected areas, there is deterioration of water quality
and decrease in population size of salamanders.
(20) Comment: SWCA (2012, p. 11) criticizes the Service and the COA
for not providing a direct cause and effect relationship between
urbanization, nutrient levels, and salamander populations. There is, in
fact, a large amount of peer-reviewed literature on the effects of
pollutants and deterioration of water quality on sensitive
macroinvertebrate species as well as on aquatic amphibians. In the
proposed rule, the Service cites just a small sampling of the available
literature regarding the effects of pollutants on the physiology and
indirect effects of urbanization on aquatic macroinvertebrates and
amphibians. In almost all cases, there are synergistic and indirect
negative effects on these species that may not have one single direct
cause. There is no ecological requirement that any stressor (be it a
predator, a pollutant, or a change in the invertebrate community) must
be a direct effect to threaten the stability or long-term persistence
of a population or species. Indirect effects can be just as important,
especially when many are combined.
Our Response to Comments 17-20: We included SWCA's (2012) report as
part of the information we asked for peer reviewers to consider. The
peer reviewers generally agreed that we used the best information
available in our proposed listing rule.
(21) Comment: One reviewer stated that, even though there is
detectable gene flow between populations, it may be representative of
subsurface connections in the past, rather than current population
interchange. However, dispersal through the aquifer is possible even
though there is currently no evidence that these species migrate.
Further, they stated that there is no indication of a metapopulation
structure where one population could recolonize another that had gone
extinct.
Our Response: We acknowledge that more study is needed to determine
the nature and extent of the dispersal capabilities of the Georgetown
and Salado salamanders. It is plausible that populations of these
species could extend through subterranean habitat. However, subsurface
movement is likely to be limited by the highly dissected nature of the
aquifer system, where spring sites can be separated from other spring
sites by large canyons or other physical barriers to movement. Dye-
trace studies have demonstrated that some Jollyville Plateau salamander
sites located miles apart are connected hydrologically (Whitewater Cave
and Hideaway Cave) (Hauwert and Warton 1997, pp. 12-13), but it remains
unclear if salamanders are travelling between those sites. We have some
indication that populations could be connected through subterranean
water-filled spaces, although we are unaware of any information on the
frequency of movements and the actual nature of connectivity among
populations.
Comments From States
Section 4(i) of the Act states, ``the Secretary shall submit to the
State agency a written justification for his failure to adopt
regulations consistent with the agency's comments or petition.''
Comments received from all State agencies and entities in Texas
regarding the proposal to list the Georgetown and Salado salamanders
are addressed below.
(22) Comment: Chippindale (2010) demonstrated that it is possible
for Jollyville Plateau salamanders to move between sites in underground
conduits. Close genetic affinities between populations in separate
watersheds on either side of the RM 620 suggest that these populations
may be connected hydrologically. Recent studies (Chippindale 2011 and
2012, in prep) indicate that gene flow among salamander populations
follows groundwater flow routes in some cases and that genetic exchange
occurs both
[[Page 10244]]
horizontally and vertically within an aquifer segment.
Our Response: We agree that genetic evidence suggests subsurface
hydrological connectivity exist between sites at some point in time,
but we are unable to conclude if this connectivity occurred in the past
or if it still occurs today without more hydrogeological studies or
direct evidence of salamander migration from mark-recapture studies.
Also, one of our peer reviewers stated that this genetic exchange is
probably representative of subsurface connection in the past (see
comment 21 above).
(23) Comment: There were insufficient data to evaluate the long-
term flow patterns of the springs and creeks, and the correlation of
flow, water quality, habitat, ecology, and community response. Current
research in Williamson County indicates that water and sediment quality
remain good with no degradation, no elevated levels of toxins, and no
harmful residues in known springs.
Our Response: We have reviewed the best available scientific and
commercial information in making our final listing determination. We
sought comments from independent peer reviewers to ensure that our
designation is based on scientifically sound data, assumptions, and
analysis. And the peer reviewers stated that our proposed rule was
based on the best available scientific information. Additionally,
recent research on water quality in Williamson County springs was
considered in our listing rule. The peer reviewers agreed that these
data did not present convincing evidence that overall water quality at
salamander sites in Williamson County is good or that urbanization is
not impacting the water quality at these sites (see Comment 19 above).
(24) Comment: The listing will have negative impacts to private
development and public infrastructure.
Our Response: In accordance with the Act, we cannot consider
possible economic impacts in making a listing determination. However,
Section 4(b)(2) of the Act states that the Secretary shall designate
and make revisions to critical habitat on the basis of the best
available scientific data after taking into consideration the economic
impact, national security impact, and any other relevant impact of
specifying any particular area as critical habitat. Economic impacts
are not taken into consideration as part of listing determinations.
(25) Comment: It was suggested that there are adequate regulations
in Texas to protect the Georgetown and Salado salamanders and their
respective habitats. The overall programs to protect water quality--
especially in the watersheds of the Edwards Aquifer region--are more
robust and protective than suggested by the Service's descriptions of
deficiencies. The Service overlooks the improvements in the State of
Texas and local regulatory and incentive programs to protect the
Edwards Aquifer and spring-dependent species over the last 20 years.
Texas has extensive water quality management and protection programs
that operate under state statutes and the Federal Clean Water Act.
These programs include: Surface Water Quality Monitoring Program, Clean
Rivers Program, Water Quality Standards, Texas Pollutant Discharge
Elimination System (TPDES) Stormwater Permitting, Total Maximum Daily
Load Program, Nonpoint Source Program, Edwards Aquifer Rules, and Local
Ordinances and Rules (San Marcos Ordinance and COA Rules). Continuing
efforts at the local, regional, and state level will provide a more
focused and efficient approach for protecting these species than
Federal listing.
Our Response: Section 4(b)(1)(A) of the Act requires us to take
into account those efforts being made by a state or foreign nation, or
any political subdivision of a state or foreign nation, to protect such
species, and we fully recognize the contributions of the state and
local programs. We consider relevant Federal, state, and tribal laws
and regulations when developing our threats analysis. Regulatory
mechanisms may preclude the need for listing if we determine such
mechanisms address the threats to the species such that listing is no
longer warranted. However, the best available scientific and commercial
data available at the time of the proposed rule supported our initial
determination that existing regulations and local ordinances were not
adequate to remove all of the threats to the Georgetown and Salado
salamanders. Since that time, the City of Georgetown approved a new
ordinance designed to reduce the threats to the Georgetown salamander.
We have added further discussion of existing regulations and ordinances
under Factor D in the final listing rule, and we have considered these
new ordinances in our threats analysis below.
(26) Comment: The requirement in the Edwards Aquifer Rules for
wastewater to be disposed of on the recharge zone by land application
is an important and protective practice for aquifer recharge and a
sustainable supply of groundwater. Permits for irrigation of wastewater
are fully evaluated and conditioned to require suitable vegetation and
sufficient acreage to protect water quality.
Our Response: Based on the best available science, wastewater
disposal on the recharge zone by land application can contribute to
water quality degradation in surface waters and the underground
aquifer. Previous studies have demonstrated negative impacts to water
quality (increases in nitrate levels) at Barton Springs (Mahler et al.
2011, pp. 29-35) and within streams (Ross 2011, pp. 11-21) that were
likely associated with the land application of wastewater.
(27) Comment: A summary of surface water quality data for streams
in the watersheds of the salamanders was provided, and a suggestion was
made that sampling data indicated high-quality aquatic life will be
maintained despite occasional instances where parameters exceeded
criteria or screening levels.
Our Response: In reviewing the 2010 and 2012 Texas Water Quality
Integrated Reports prepared by the Texas Commission on Environmental
Quality (TCEQ), the Service identified 3 of 7 (43 percent) and 2 of 2
(100 percent) stream segments located within surface drainage areas
occupied by the Georgetown and Salado salamanders respectively, which
contained measured parameters within water samples that exceeded
screening level criteria. These included ``screening level concerns''
for parameters such as nitrate, dissolved oxygen, and impaired benthic
communities. Water quality data collected and summarized in TCEQ
reports supports concerns for the potential for water quality
degradation within the surface drainage areas occupied by the
salamanders. This information is discussed under Summary of Factors
Affecting the Species in this final listing rule.
(28) Comment: The City of Georgetown ordinance reduces the threats
to surface habitat conditions and water quality for the Georgetown
salamander.
Our response: The Service agrees that the City of Georgetown
ordinance will reduce some of the threats to the Georgetown salamander.
We have provided a discussion on the effectiveness of the City of
Georgetown's ordinance in reducing the threats to the Georgetown
salamander under Summary of Factors Affecting the Species below in the
final listing rule.
Public Comments
Existing Regulatory Mechanisms
(29) Comment: The Service improperly discounts the value of
[[Page 10245]]
TCEQ's Optional Enhanced Measures by concluding that, because they are
optional as to non-listed species, ``take'' prohibitions do not apply
and they are not a regulatory mechanism. However, in February 14, 2005,
the Service stated in a letter to Governor Rick Perry that
implementation of the Enhanced Measures would result in ``no take'' of
various aquatic species, including the Georgetown salamander.
Our Response: With the listing of the Georgetown and Salado
salamanders, the Act and its implementing regulations set forth a
series of general prohibitions and exceptions that apply to all
endangered and threatened wildlife. The prohibitions of section 9(a)(2)
of the Act, codified at 50 CFR 17.21 and 50 CFR 17.31, make it illegal
for any person subject to the jurisdiction of the United States to take
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect; or to attempt any of these), import, export, ship
in interstate commerce in the course of commercial activity, or sell or
offer for sale in interstate or foreign commerce any listed species.
Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C. 3371-3378), it is also
illegal to possess, sell, deliver, carry, transport, or ship any such
wildlife that has been taken illegally. We may issue permits to carry
out otherwise prohibited activities involving endangered and threatened
wildlife species under certain circumstances, but such a permit must be
issued for scientific purposes, to enhance the propagation or survival
of the species, and for incidental take in connection with otherwise
lawful activities. The Service's 2005 and 2007 letters to Governor Rick
Perry were made prior to listing of the Georgetown and Salado
salamanders and do not constitute a permit that allows for take under
the Act.
We have changed the wording in the final listing rule to more
accurately reflect our opinion that the Optional Enhanced Measures may
provide protection to the species, but do not constitute a regulatory
mechanism because they are voluntary. These measures were intended to
be used for the purpose of avoiding harm to the identified species from
water quality impacts, not to address any of the other threats to the
Georgetown salamander. TCEQ reported that only 17 Edwards Aquifer
applications have been approved under the Optional Enhanced Measures
between February 2005 and May 2012, and the majority of these
applications were for sites in the vicinity of Dripping Springs, Texas,
which would not pertain to the Georgetown salamander (Beatty 2012,
TCEQ, pers. comm.).
(30) Comment: The Service's February 14, 2005, and September 4,
2007, letters to Governor Rick Perry concurred that non-federal
landowners and other non-federal managers using the voluntary measures
in Appendix A to the TCEQ technical guidance manual for the Edwards
Aquifer Protection Program would have the support of the Service that
``no take'' under the Act would occur unless projects met specific
criteria listed in the letters.
Our Response: See our response to comment (29) above.
(31) Comment: Many commenters expressed concern that the Service
had not adequately addressed all of the existing regulatory mechanisms
and programs that provided protection to the salamanders. In addition,
many of the same commenters believed there were adequate state,
Federal, and local regulatory mechanisms to protect the salamanders and
their aquatic habitats.
Our Response: Section 4(b)(1)(A) of the Act requires us to take
into account those efforts being made by a state or foreign nation, or
any political subdivision of a state or foreign nation, to protect such
species. Under D. The Inadequacy of Existing Regulatory Mechanisms in
the final listing rule, we provide an analysis of the inadequacy of
existing regulatory mechanisms. During the comment period, we sought
out and were provided information on several local, state, and Federal
regulatory mechanisms that we had not considered when developing the
proposed rule. We have reviewed these mechanisms and have included them
in our analysis under D. The Inadequacy of Existing Regulatory
Mechanisms in the final listing rule. In addition, during the 6-month
extension the City of Georgetown approved a new ordinance designed to
reduce the threats to the Georgetown salamander. We have included this
ordinance in our discussion under Summary of Factors Affecting the
Species below in the final listing rule.
Protections
(32) Comment: The Service fails to consider existing local
conservation measures and habitat conservation plans (HCPs) that
benefit the salamanders. While the salamanders are not covered in most
of these HCPs, some commenters believe that measures are in place to
mitigate any imminent threats to the species. The Service overlooks
permanent conservation actions undertaken by both public and private
entities over the last two or more decades. The HCPs and water quality
protection standards are sufficient to prevent significant habitat
degradation.
Our Response: In the final listing rule, we included a section
titled ``Conservation Efforts to Reduce Habitat Destruction,
Modification, or Curtailment of Its Range'' that describes existing
conservation measures including the regional permit issued to the
Williamson County Regional HCP. These conservation efforts and the
manner in which they are helping to ameliorate threats to the species
were considered in our final listing determination. The Service
considered the amount and location of managed open space when analyzing
impervious cover levels within each surface watershed (Service 2012,
2013). We also considered preserves when projecting how impervious
cover levels within the surface watershed of each spring site would
change in the future. These analyses included the benefits from open
space as a result of several HCPs, including Buttercup Creek HCP,
Balcones Canyonlands Conservation Plan, Lakeline Mall HCP, Concordia
HCP, Four Points HCP, and Grandview Hills HCP. Of these, only the
Williamson County HCP and Lakeline Mall HCP created open space within
the range of the Georgetown salamander (no HCPs have established open
space within the range of the Salado salamander). While these
conservation lands contribute to the protection of the surface and
subsurface watersheds, there are other factors contributing to the
decline of the salamander's habitat. Other factors include, but are not
limited to: (1) Other areas within the surface watershed that have high
levels of impervious cover, which increases the overall percentage of
impervious cover within the watershed; (2) potential for groundwater
pollution from areas outside of the surface watershed; and (3)
disturbance of the surface habitat of the spring sites themselves.
(33) Comment: Multiple commenters stated that the Georgetown
salamander's known distribution is entirely contained within the
jurisdictional boundaries of the Williamson County Regional HCP (RHCP)
and is thusly already protected. The RHCP includes provisions for
studying the Georgetown salamander and numerous conservation actions
benefitting the species. To date, 47 entities have participated in the
RHCP and the Williamson County Conservation Fund (WCCF) has permanently
preserved 664 ac (269 ha) within 8 preserves. As part of the RHCP, a
commitment was made to conduct a 5-year study of the Georgetown
salamander and drafting of a
[[Page 10246]]
conservation strategy. In 2008, based on these actions, the Service
reduced the listing priority category for the Georgetown salamander
from a 2 to an 8.
Our Response: We agree with the commenters that the RHCP permit
area contains the entire range of the Georgetown salamander, and also
includes a portion of the Jollyville Plateau salamander within its
permit area. Furthermore, we agree that some of the land preserved by
the RHCP as mitigation for the impacts of covered activities on
endangered invertebrate species is contributing to protection of a
limited amount of salamander habitat. However, the RHCP does not permit
``take'' of salamanders as covered species, accordingly the permit does
not require mitigation for the impacts of the covered actions on any
salamander species. The RHCP notes on page 4-19 that actions authorized
by the RHCP for covered species ``. . . may impact the Georgetown
salamander by degrading water quality and quantity in springs and
streams in the watersheds where the species occurs.'' One of the RHCP's
biological goals is to help conserve the salamanders by studying the
Georgetown salamander's status, distribution, and conservation needs.
In addition to a 5-year Georgetown salamander research and monitoring
program, Williamson County committed to drafting a conservation
strategy for the species, based on initial findings of the research,
and coordinating a public education and outreach program. While this
research to date has been incorporated in the final listing rule, the
best available information supports our conclusion that the threats to
the species are not ameliorated by the RHCP.
The listing priority number was lowered from a 2 to an 8 for the
Georgetown salamander based on conservation actions by WCCF in 2008 (73
FR 75176, December 10, 2008). A listing priority of 8 indicates that
there are imminent threats to the species, but the magnitude of these
imminent threats is moderate to low.
(34) Comment: The proposed rule directly contradicts the Service's
recent policy titled Expanding Incentives for Voluntary Conservation
Actions Under the Act (77 FR 15352, March 15, 2012), which concerns the
encouragement of voluntary conservation actions for non-listed species
and is available at http://www.gpo.gov/fdsys/pkg/FR-2012-03-15/pdf/2012-6221.pdf.
Our Response: The commenter did not specify how the proposed rule
contradicts the Service's recent policy pronouncements concerning the
encouragement of voluntary conservation actions for non-listed species.
The recent policy pronouncements specifically state that voluntary
conservation actions undertaken are unlikely to be sufficient to affect
the need to list the species. However, if the species is listed and
voluntary conservation actions are implemented, as outlined in policy
pronouncements, the Service can provide assurances that if the
conditions of a conservation agreement are met, the landowner will not
be asked to do more, commit more resources, or be subject to further
land use restrictions than agreed upon. We may also allow a prescribed
level of incidental take by the landowner.
(35) Comment: Existing protective measures and current land-use
conditions in the contributing zone of the Northern Segment of the
Edwards Aquifer negate the justification for the proposed listing of
the Salado salamander. It was the understanding of Bell County that the
development of comprehensive conservation strategies or plans to
protect species would be based on additional research that will be
conducted in a cooperative effort involving state and Federal
environmental agencies and local stakeholders. Consistent with the
guidance of agency officials, Bell County and their partners held
public hearings and entered into contractual agreements with experts.
Fieldwork related to those studies is about to commence.
Our Response: The Service appreciates the efforts of Bell County
and their partners to conduct research and collect additional data to
support the conservation of the Salado salamander. The Service is
required to make a determination on the status of the Salado salamander
based on the best available science at the time we make our listing
decision. The Service looks forward to continuing to work with Bell
County and all of our other partners to further the conservation of the
Salado salamander. We anticipate the additional research and
information being gathered by Bell County and others will be helpful in
refining conservation strategies and adapting management for these
species, based on this new information.
(36) Comment: The proposed rule cites the vested rights statute
found in Chapter 245, Texas Local Government Code as a weakness in
local and state regulations. Chapter 245 does not apply to state
regulations. Under Chapter 245, a ``regulatory agency'' is defined as a
political subdivision of the state such as a county, school district or
municipality (Section 245.001(2) & (4), Texas Local Government Code).
The Edwards Rules for the Contributing Zone revised in 1999 had a very
narrow grandfathering provision from the new regulations: A project did
not have to comply with the new rules if the project had all of the
permits necessary to begin construction on June 1, 1999, and
construction began by December 1, 1999. No projects can possibly exist
that are grandfathered from the Edwards Rules for the contributing zone
of the Edwards Aquifer.
Our Response: We have revised this discussion in this final rule,
as appropriate.
Listing Process and Policy
(37) Comment: Reducing the Listing Priority Number of the
Georgetown salamander from 2 to 8 indicates no imminent threat to the
species.
Our Response: In the 2008 candidate notice of review, the listing
priority number was lowered from 2 to 8. However, a listing priority of
8 indicates that there are imminent threats to the species, but the
magnitude of these imminent threats is moderate to low.
(38) Comment: The Service is pushing these listings because of the
legal settlement and not basing its decision on science and the reality
of the existing salamander populations.
Our Response: We are required by court-approved settlement
agreements to remove the Georgetown and Salado salamanders from the
candidate list within a specified timeframe. To remove these
salamanders from the candidate list means to propose them for listing
as endangered or threatened or to prepare a not-warranted finding. The
Act requires us to determine whether a species warrants listing based
on our assessment of the five listing factors described in the Act
using the best available scientific and commercial information. We
already determined, prior to the court settlement agreement, that the
Georgetown and Salado salamanders warranted listing under the Act, but
were precluded by the necessity to commit limited funds and staff to
complete higher priority species actions. These salamanders have been
included in our annual Candidate Notices of Review for multiple years,
during which time scientific literature and data have and continue to
indicate that these salamanders are detrimentally impacted by ongoing
threats, and we continued to find that listing each species was
warranted but precluded. While the settlement agreement has set a
court-ordered timeline for rendering our final decision, our
determination is still guided by the Act and its
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implementing regulations considering the five listing factors and using
the best available scientific and commercial information.
(39) Comment: Commenters requested that the Service extend the
comment period for another 45 days after the first comment period. The
commenters were concerned about the length of the proposed listing,
which is very dense and fills 88 pages in the Federal Register, and
that the public hearing was held only 2 weeks after the proposed rule
was published. Commenters do not consider this enough time to read and
digest how the Service is basing a listing decision that will have
serious consequences for Williamson County. Furthermore, the 60-day
comment period does not give the public enough time to submit written
comments to such a large proposed rule.
Our Response: The initial comment period for the proposed listing
and critical habitat designation consisted of 60 days, beginning August
22, 2012, and ending on October 22, 2012. We reopened the comment
period for an additional 45 days, beginning on January 25, 2013, and
ending on March 11, 2013. During our 6-month extension on the final
determination for the Georgetown and Salado salamanders, we reopened
the comment period from August 20, 2013, to September 19, 2013 (78 FR
51129). On January 7, 2014, we reopened the comment period and
announced the availability of the City of Georgetown's final ordinance
for water quality and urban development (79 FR 800). We reopened the
comment period to allow all interested parties an opportunity to
comment simultaneously on the proposed rule and the effect of the new
city ordinances on threats to the Georgetown salamander. That comment
period closed on January 22, 2014. We consider the comment periods
described above an adequate opportunity for public comment.
(40) Comment: The Service has openly disregarded a contractual
agreement (RHCP) with Williamson County that provided for additional
study, violating mandatory process under the Act. It was our
understanding that the development of comprehensive conservation
strategies or plans to protect the species would be based on additional
research, which would be conducted in a cooperative effort involving
state and Federal environmental agencies and local stakeholders.
Williamson County has committed funds and entered into contractual
agreements with respected experts to perform these additional baseline
studies. The Service has violated a contractual agreement under the
Act.
Our Response: The RHCP is not a contract. By moving forward with a
listing decision for the Georgetown and Salado salamanders, the Service
has not violated any mandatory process under the Act or any contractual
agreement with Williamson County. The RHCP was established in 2008 to
provide incidental take coverage for the federally listed golden-
cheeked warbler (Dendroica chrysoparia), black-capped vireo (Vireo
atricapilla), Bone Cave harvestman (Texella reyesi), and Coffin Cave
mold beetle (Batrisodes texanus). A number of conservation actions for
the Georgetown salamander were planned in the RHCP, but the Georgetown
salamander is not a covered species under the RHCP. One of the
conservation actions is for WCCF to conduct a 5-year research and
monitoring study for the Georgetown salamander, which was planned with
the intention of preparing a Candidate Conservation Agreement with
Assurances if the species was still a candidate at the end of the
study. The RHCP does not include an agreement between the Service and
Williamson County to delay the listing of the Georgetown salamander
until the study is completed.
(41) Comment: One commenter expressed concern with the use of
``unpublished'' data in the proposed rule. It is important that the
Service takes the necessary steps to ensure all data used in the
listing and critical habitat designations are reliable, verifiable, and
peer reviewed, as required by President Obama's 2009 directive for
transparency and open government. In December of 2009, the Office of
Management and Budget (OMB) issued clarification on the presentation
and substance of data used by Federal agencies and required in its
Information Quality Guidelines. Additionally under the OMB guidelines,
all information disseminated by Federal agencies must meet the standard
of ``objectivity.'' Additionally, relying on older studies instead of
newer ones conflicts with the Information Quality Guidelines.
Our Response: Our use of unpublished information and data does not
contravene the transparency and open government directive. Under the
Act, we are obligated to use the best available scientific and
commercial information, including results from surveys, reports by
scientists and biological consultants, various models, and expert
opinion from biologists with extensive experience studying the
salamanders and their habitat, whether published or unpublished. One
element of the transparency and open government directive encourages
executive departments and agencies to make information about operations
and decisions readily available to the public. Supporting documentation
used to prepare the proposed and final rules is available for public
inspection, by appointment, during normal business hours, at the U.S.
Fish and Wildlife Service, Austin Ecological Services Field Office,
10711 Burnet Rd., Suite 200, Austin, TX 78758.
Peer Review Process
(42) Comment: One commenter requested that the Service make the
peer review process as transparent and objective as possible. The
Service should make available the process and criteria used to identify
peer reviewers. It is not appropriate for the Service to choose the
peer review experts. For the peer review to be credible, the entire
process including the selection of reviewers must be managed by an
independent and objective party. We recommend that the peer review plan
identify at least two peer reviewers per scientific discipline.
Further, the peer reviewers should be identified.
Our Response: To ensure the quality and credibility of the
scientific information we use to make decisions, we have implemented a
formal peer review process. Through this peer review process, we
followed the guidelines for Federal agencies spelled out in the Office
of Management and Budget (OMB) ``Final Information Quality Bulletin for
Peer Review'' released December 16, 2004, and the Service's
``Information Quality Guidelines and Peer Review'' revised June 2012.
Part of the peer review process is to provide information online about
how each peer review is to be conducted. Prior to publishing the
proposed listing and critical habitat rule for these salamanders, we
posted a peer review plan on our Web site, which included information
about the process and criteria used for selecting peer reviewers, and
we posted the peer reviews on http://www.regulations.gov.
In regard to transparency, the OMB and Service's peer review
guidelines mandate that we not conduct anonymous peer reviews. The
guidelines state that we advise reviewers that their reviews, including
their names and affiliations, and how we respond to their comments will
be included in the official record for review, and once all the reviews
are completed, their reviews will be available to the public. We
followed the policies and standards for conducting
[[Page 10248]]
peer reviews as part of this rulemaking process.
(43) Comment: The results of the peer review process should be
available to the public for review and comment well before the end of
the public comment period on the listing decision. Will the public have
an opportunity to participate in the peer review process?
Response: As noted above, OMB and the Service's guidelines state
that we make available to the public the peer reviewers' information,
reviews, and how we respond to their comments once all reviews are
completed. The peer reviews are completed at the time the last public
comment period closes, and our responses to their comments are
completed at the time the final listing decision is published in the
Federal Register. All peer review process information is available upon
request at this time and is available from the U.S. Fish and Wildlife
Service, Austin Ecological Services Field Office, 10711 Burnet Rd,
Suite 200, Austin, TX 78758. In addition, the peer reviews have been
posted at http://www.regulations.gov.
(44) Comment: New information has been provided during the comment
period. The generalized opinions of the initial peer reviewers
regarding the proposed rule having the best available science is
largely negated by the significant quantity of materials submitted by
the public during the first two comment periods. In other words, the
large quantity of additional information submitted into the record
clearly demonstrates that the proposed rule did not reflect the best
available scientific and commercial data. The final listing decision
should be peer reviewed.
Response: During the second public comment period, we asked peer
reviewers to comment on new and substantial information that we
received during the first comment period. We did not receive any new
information during the second comment period that we felt rose to the
level of needing peer review. Furthermore, as part of our peer review
process, we asked peer reviewers not to provide comments or
recommendations on the listing decision. Peer reviewers were asked to
comment specifically on the quality of information and analyses used or
relied on in the reviewed documents. In addition, they were asked to
identify oversights, omissions, and inconsistencies; provide advice on
reasonableness of judgments made from the scientific evidence; ensure
that scientific uncertainties are clearly identified and characterized
and that potential implications of uncertainties for the technical
conclusions drawn are clear; and provide advice on the overall
strengths and limitations of the scientific data used in the document.
(45) Comment: One commenter requested a peer review of the four
central Texas salamanders' taxonomy and recommended that, to avoid any
potential bias, peer reviewers not be from Texas or be authors or
contributors of any works that the Service has or is relying upon to
diagnose the four central Texas salamanders as four distinct species.
This commenter also provided a list of four recommended scientists for
the peer review on taxonomy.
Our Response: We requested peer reviews of the central Texas
salamander taxonomy from 11 scientific experts in this field. Because
we considered the 4 recommended scientists to be qualified as
independent experts, we included the 4 experts recommended by the
commenter among the 11. Eight scientists responded to our request, and
all eight scientists agreed with our recognition of four separate and
distinct salamander species, as described in the Species Information
section of the proposed and final listing rules. The commenter also
provided an unpublished paper offering an alternative interpretation of
the taxonomy of central Texas salamanders (Forstner 2012, entire), and
that information was also provided to peer reviewers. We included two
authors of the original species descriptions of the four central Texas
salamander species to give them an opportunity to respond to criticisms
of their work and so that we could fully understand the taxonomic
questions about these species.
(46) Comment: One commenter requested a revision to the peer review
plan to clarify whether it is a review of non-influential information
or influential information.
Our Response: We see no benefit from revising the peer review plan
to clarify whether the review was of non-influential or influential
information. The Service's ``Information Quality Guidelines and Peer
Review,'' revised June 2012, defines influential information as
information that we can reasonably determine the dissemination of which
will have or does have a clear and substantial impact on important
policy or private sector decisions. Also, we are authorized to define
influential in ways appropriate for us, given the nature and
multiplicity of issues for which we are responsible. As a general rule,
we consider an impact clear and substantial when a specific piece of
information is a principal basis for our position.
(47) Comment: One commenter requested clarification on what type of
peer review was intended. Was it a panel review or individual review?
Did peer reviewers operate in isolation to generate individual reports
or did they work collaboratively to generate a single peer review
document.
Our Response: Peer reviews were requested individually. Each peer
reviewer who responded generated independent comments.
(48) Comment: It does not seem appropriate to ask peer reviewers,
who apparently do not have direct expertise on Eurycea or central Texas
ecological systems, to provide advice on reasonableness of judgments
made from generic statements or hyper-extrapolations from studies on
other species. The peer review plan states that reviewers will have
expertise in invertebrate ecology, conservation biology, or desert
spring ecology. The disciplines of invertebrate ecology and desert
spring ecology do not have any apparent relevance to the salamanders in
question. The Eurycea are vertebrate species that spend nearly all of
their life cycle underground. Central Texas is not a desert. The peer
reviewers should have expertise in amphibian ecology and familiarity
with how karst hydrogeology operates.
Our Response: The peer review plan stated that we sought out peer
reviewers with expertise in invertebrate ecology or desert spring
ecology, but this was an error which was corrected in our
correspondence with the peer reviewers. In the first comment period, we
asked and received peer reviews from independent scientists with local
and non-local expertise in amphibian ecology, amphibian taxonomy, and
karst hydrology. In the second comment period, we sought out peer
reviewers with local and non-local expertise in population ecology and
watershed urbanization.
(49) Comment: The peer review plan appears to ask peer reviewers to
consider only the scientific information reviewed by the Service. The
plan should include the question of whether the scientific information
reviewed constitutes the best available scientific and commercial data.
The plan should be revised to clarify that the peer reviewers are not
limited to the scientific information in the Service's administrative
record.
Our Response: The peer review plan states that we may ask peer
reviewers to identify oversights and omissions of information as well
as to consider the information reviewed by the Service. When we sent
out letters to peer reviewers asking for their review, we specifically
asked them to identify any oversights, omissions, and
[[Page 10249]]
inconsistencies with the information we presented in the proposed rule.
(50) Comment: The proposed peer review plan falls far short of the
OMB Guidelines (2004 Office of Management and Budget promulgated its
Final Information Quality Bulletin for Peer Review).
Our Response: This commenter failed to tell us how the plan falls
short of the OMB Guidelines. We adhered to the guidelines set forth for
Federal agencies and in OMB's ``Final Information Quality Bulletin for
Peer Review,'' released December 16, 2004, and the Service's
``Information Quality Guidelines and Peer Review,'' revised June 2012.
While the draft peer review plan had some errors, we believe we
satisfied the intent of the guidelines and that the errors did not
affect the rigor of the actual peer review that occurred.
(51) Comment: One commenter stated that an additional peer review
plan was not made available to the public for the second peer review.
Our Response: We followed our peer review policy to prepare a peer
review plan for our proposed rules, and we made the plan available for
public review on our Web site. Both of our peer review processes
followed this plan.
Salamander Populations
(52) Comment: A recent study by SWCA proposes that the COA's data
are inadequate to assess salamander population trends and is not
representative of environmental and population control factors (such as
seasonal rainfall and drought). The study also states that there is
very little evidence linking increased development to declining water
quality.
Our Response: We have reviewed the report by SWCA and COA's data
and determined that it is reasonable to conclude that a link between
increased urban development, declining water quality, and declining
salamander populations exists for these species. Peer reviewers have
also generally agreed with this assessment.
(53) Comment: The WCCF has been conducting research on salamanders
of the Northern Edwards Aquifer since 2008. This included population
monitoring at two Georgetown salamander sites and recently expanded to
include water quality testing in both Georgetown salamander and
Jollyville Plateau salamander ranges. Data indicate that populations
are stable and healthy and water quality at Williamson County springs
is excellent.
Our Response: We acknowledge that two Georgetown salamander sites
in Williamson County have been regularly monitored since 2008, and we
have considered this data in the final listing rule. However, water
quality testing by WCCF at salamander sites has only recently been
initiated, and no conclusions regarding long-term trends in water
quality at Georgetown salamander sites can be made. Furthermore, this
salamander count dataset has not been conducted over a long enough time
period to conclude that the salamander populations are stable and
healthy at the two monitored sites.
(54) Comment: Specifically related to the Salado salamander, we
note an apparent inconsistency in the proposed rule related to the
locations of specific springs where the animal has been found. The
section on impervious cover states, ``The Salado salamander occurs
within two watersheds (Buttermilk Creek and Mustang Creek).'' In fact,
to our knowledge the animal has been found in neither. The section
discussing the specific springs identifies occurrences in springs in
the Rumsey Creek and Salado Creek watersheds. The latter section
appears to be correct.
Our Response: Buttermilk Creek and Mustang Creek are the names of
the 12-digit Hydrologic Unit Codes we used in our initial impervious
cover analysis. They are larger watersheds that contain the smaller
watersheds of Rumsey Creek and Salado Creek, which contain the springs
occupied by the Salado salamander.
(55) Comment: The Service has no evidence that shows what the
Georgetown salamander population is, or what a healthy average
population would look like.
Our Response: Although population data are lacking for most
Georgetown salamander sites, population estimates of Georgetown
salamanders have recently been completed at Twin Springs (118-216
adults) and Swinbank Spring (102-137 adults) (Pierce 2011a, p. 12).
Part of what constitutes a healthy population is that threats have been
removed or minimized. In terms of population size, it is unknown how
many individuals are needed within a population to ensure its
persistence over the long term.
(56) Comment: Given the central Texas climate and the general
geology and hydrology of the Edwards Limestone formation north of the
Colorado River, the description ``surface-dwelling'' or ``surface
residing'' overstates the extent and frequency that the Georgetown and
Salado salamanders utilize surface water. The phrase ``surface dwelling
population'' in the proposed rule appears to be based on two
undisclosed and questionable assumptions pertaining to Georgetown and
Salado salamanders: (1) There are a sufficient number of these
salamanders that have surface water available to them for sufficient
periods of times so that the group could be called a ``population'';
and (2) there are surface-dwelling Jollyville Plateau salamander
populations that are distinct from subsurface dwelling Jollyville
Plateau salamander populations. Neither assumption can be correct
unless the surface area is within a spring-fed impoundment that
maintains water for a significant portion of a year.
Our Response: In the proposed rule, we did not mean to imply or
assume that ``surface-dwelling populations'' are restricted to surface
habitat only. In fact, we made clear in the proposed rule that these
populations need access to subsurface habitat. In addition, we also
considered the morphology of these species in our description of their
habitat use. The morphology of the Georgetown salamander and Salado
salamanders serve as indicators of surface and subsurface habitat use.
The Georgetown salamander surface populations have large, well-
developed eyes. In addition, the Georgetown salamander has yellowish-
orange tails, bright-red gills, and varying patterns of melanophores.
The subterranean populations of the Georgetown salamander have reduced
eyes and dullness of color, indicating adaptation to subsurface
habitat. The Salado salamander has reduced eyes and lacks well-defined
melanophores in comparison to other surface-dwelling Eurycea. However,
they do possess developed eyes and some pigmentation, indicating some
use of surface habitat.
(57) Comment: There may be uncertainty as to the number of Salado
salamander populations, and how prolific the subsurface populations
are. However, it is apparent that the species has historically been and
currently is extremely difficult to observe and collect during low to
average spring flows at the Salado Springs complex and more abundant
and readily observable during above-average spring flows at the Salado
Springs complex. The exception has been the spring outlets located in
the Edwards outcrop upstream of the Salado Springs complex, where the
salamander has been observed regularly during below-average spring
flow. The consistency in observations from species surveys over the
past 60 or more years is important: they do not reflect a trend
downward in species population.
Our Response: We agree that the available data on Salado salamander
observations do not reflect a declining trend over time. However, these
data are
[[Page 10250]]
also neither quantitative nor consistent enough to conclude that any
Salado salamander population has been stable over time. The fact that
Salado salamanders are rarely found at sites near the Village of Salado
during periods of low flow suggests that this species is sensitive to
threats such as drought and urbanization, as has been demonstrated for
several closely related salamander species.
Threats
(58) Comment: The Service appears reluctant to distinguish between
what are normal, baseline physical conditions (climate, geology, and
hydrology) found in central Texas and those factors outside of the norm
that might actually threaten the survival of the salamander species.
Cyclical droughts and regular flood events are part of the normal
central Texas climate and have been for thousands of years. The Service
appears very tentative about accepting the obvious adaptive behaviors
of the salamanders to survive floods and droughts.
Our Response: The final listing rule acknowledges that drought
conditions are common to the region, and the ability to retreat
underground may be an evolutionary adaptation to such natural
conditions (Bendik 2011a, pp. 31-32). However, it is important to note
that although salamanders may survive a drought by retreating
underground, this does not necessarily mean they are resilient to
future worsening drought conditions in combination with other
environmental stressors. For example, climate change, groundwater
pumping, decreased water infiltration to the aquifer, potential
increases in saline water encroachments in the aquifer, and increased
competition for spaces and resources underground all may negatively
affect their habitat (COA 2006, pp. 46-47; TPWD 2011, pp. 4-5; Bendik
2011a, p. 31; Miller et al. 2007; p. 74; Schueler 1991, p. 114). These
factors may exacerbate drought conditions to the point where
salamanders cannot survive. In addition, we recognize threats to
surface habitat at a given site may not extirpate populations of these
salamander species in the short term, but this type of habitat
degradation may severely limit population growth and increase a
population's overall risk of extirpation from cumulative impacts of
other stressors occurring in the surface watershed of a spring.
(59) Comment: There is no proof that Salado salamanders surfacing
from the aquifer after spending lengthy periods subsurface are
emaciated, or otherwise in a weakened state, or that they were unable
to reproduce.
Our Response: No studies have examined the biological effects of
drought on Salado salamanders. However, a study on the closely related
Jollyville Plateau salamander has documented decreases in body length
following periods of drought (Bendik and Gluesenkamp 2013, pp. 3-4). In
the absence of species-specific information, we conclude that the
Salado salamander responds to drought in a similar way.
(60) Comment: In the proposed rule, the Service states that
``Central Texas salamanders are particularly vulnerable to
contaminants, because they have evolved under very stable environmental
conditions.'' The cycle of droughts and pulse rain events is certainly
not a stable environmental condition. Drought is a stressor on all life
forms in central Texas and necessitates species adaptability to
survive.
Our Response: This statement in the proposed rule refers to the
presence of contaminants in the salamanders' habitat, not the
occurrence of drought. Contaminants are a relatively new stressor for
these species that has been introduced by human activity.
(61) Comment: The watershed recharging the Salado salamander
occupied springs is largely undeveloped and little urbanization is
occurring. There is no evidence that rapid urbanization is likely to
occur in the foreseeable future in these watersheds due to lack of
infrastructure. The population estimates in the proposed rule are based
on countywide figures for Bell and Williamson Counties. Countywide
figures grossly overstate the amount of population growth occurring in
these specific watersheds. This can be confirmed by a review of census
tracts data. Likewise, a significant portion of northwestern Williamson
County outside of the jurisdiction of the main cities is undeveloped
and lacking in available utilities to support dense development.
Our Response: The proposed rule cites projected population growth
and expected increases in demand for residential development,
groundwater pumping, infrastructure, and other municipal services as a
threat to the species throughout the Edwards Aquifer, including areas
of Williamson and Bell Counties in the Northern Segment of the Aquifer.
The estimates of growth came from multiple sources, including the Texas
Water Development Board, the U.S. Census Bureau, and the Texas State
Data Center. We are not aware of census tract data that project future
populations at a scale lower than the county level. We maintain our
conclusion that the Georgetown and Salado salamanders warrant listing
partly due to projected human growth throughout their range.
(62) Comment: The average annual low flow of the Salado Springs
complex was approximately 4.6 cubic feet per second (cfs), which
occurred during the extreme drought in the mid-1950s. The low-end
annual average range of spring flows from late 2011 to date exceeds and
is nearly double that of the 4.6 cfs benchmark, even though the south
central Texas region has been experiencing one of the worst droughts in
recorded history. Clearwater Underground Water Conservation District's
(CUWCD) records reflect that pumping from the Edwards aquifer within
Bell County during the summer months actually decreased from 2011 to
2012 to 2013, which we believe is attributable to implementation of the
drought management program. Thus, it is apparent that drought
conditions, rather than some human agency, are responsible for low
spring flows and that, possibly, groundwater district regulation of
pumping could be having a positive effect on flows during the 2011 to
2013 drought conditions.
Our Response: We acknowledge that drought has likely influenced
spring flow for Salado salamander habitat more than groundwater
pumping. Under Factor D of the final listing rule, we also acknowledge
the water quantity protections afforded to Salado salamander habitat by
the CUWCD. However, even under these protections, springs occupied by
Salado salamanders are known to go dry for periods of time. The Service
recognizes the desired future condition adopted by the CUWCD as a
valuable tool for protecting groundwater; however, it is not adequate
to ensure spring flow at all sites occupied by the Salado salamander.
(63) Comment: In regards to the Salado salamander, threats under
Factor A are excessively vague and rest on certain assumptions which
are clearly false. The Salado salamander has been found in springs in
several locations and likely exists at others and the proposed
designation of critical habitat treats every location where Eurycea has
been identified the same. In fact, while the hydrogeologic context is
generally consistent across the region, specific structural features
may vary widely from one location to the next, so protective measures
appropriate for one location may not be appropriate elsewhere. We can
divide the springs into two basic types: (1) The Village of Salado
springs, which represent the
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ultimate outflow from the system as a whole, and (2) numerous lesser
springs occurring at various locations up in the recharge (outcrop)
zone. In either case, the springs are found in areas where extensive,
structural disturbance is unlikely and where no identifiable threats
related to possible changes in land use are anticipated at this time.
Because the major spring flows are moving through confined
segments, bounded on their upper limit by an impervious unit, they are
effectively insulated and protected from infiltration in the near
vicinity of the springs. This is supported by the discussion of water
temperature presented in the recently released TPWD report, A
Biological and Hydrological Assessment of the Salado Springs Complex,
Bell County, Texas, August 2012. Normal human activities, including
typical construction, in near proximity to the springs, present little
threat to the aquifer or the outflow from it. Further, the surrounding
area has been fully developed for over 150 years. The lesser springs up
in the recharge zone enjoy certain protections as well. Without
exception, these are located in undeveloped settings that may be
described as pristine. Specifically, the springs where the Salado
salamander has been found are on a single, award-winning ranch, which
constitutes one of the largest single land holdings in Bell County. The
owners of this property have been widely recognized for their committed
stewardship of the land. The ranch is operated under a management model
that emphasizes low-impact grazing and recreational hunting. Habitat
preservation and improvement are central components in this management
model.
Our Response: While it is possible that Salado salamanders exist at
other unknown spring locations, our evaluation of the status of the
species is limited to sites known to be occupied by the species at the
time of the proposed listing. We agree that many site-specific
variables affect both the degree of threat and potential for habitat
modification at springs occupied by Salado salamanders, including land
ownership, land uses in the immediate watershed, land uses in recharge
areas, spring flow, level of recreation and physical disturbance, water
quality, and other factors. Although we recognize the level of threat
will vary across the range of the species, and recognize the strong
stewardship of many landowners, we conclude that Factor A is neither
vague nor based on false assumptions due to documented modifications to
habitat within the very restricted range of the Salado salamander.
Although construction near spring outlets may have relatively little
impact on the entire aquifer, this type of development may likely have
large impacts on the surface habitat of the spring. The springs within
the Village of Salado have had heavy modification of the surface
habitat, as described under Factor A of the proposed rule. Despite
numerous field surveys over the last decade, Salado salamanders in many
springs near well-developed areas, such as Big Boiling Spring, are
rarely found. We consider habitat modification a significant threat,
both now and in the future, due to projected growth, current land use
practices, threats to water quality and quantity, as well as historical
and ongoing physical disturbance to spring habitat.
(64) Comment: Through measuring water-borne stress hormones,
researchers found that salamanders from urban sites had significantly
higher corticosterone stress hormone levels than salamanders from rural
sites. This finding serves as evidence that chronic stress can occur as
development encroaches upon these spring habitats.
Our Response: We are aware that researchers are pursuing this
relatively new approach to evaluate salamander health based on
differences in stress hormones between salamanders from urban and non-
urban sites. Stress levels that are elevated due to natural or
unnatural (that is, anthropogenic) environmental stressors can affect
an organism's ability to meet its life-history requirements, including
adequate foraging, predator avoidance, and reproductive success. We
encourage continued development of this and other non-lethal scientific
methods to improve our understanding of salamander health and habitat
quality.
(65) Comment: Information in the proposed rule does not discern
whether water quality degradation is due to development or natural
variation in flood and rainfall events. Fundamental differences in
surface counts of salamanders between sites are due to a natural
dynamic of an extended period of above-average rainfall followed by
recent drought.
Our Response: We recognize that aquatic-dependent organisms such as
the Georgetown and Salado salamanders will respond to local weather
conditions; however, the best available science indicates that rainfall
alone does not explain lower salamander densities at urban sites
monitored by the COA. Furthermore, there is scientific consensus among
numerous studies on the impacts of urbanization that conclude species
diversity and abundance consistently declines with increasing levels of
development, as described under Factor A in the final listing rule.
(66) Comment: Studies carried out by the Williamson County
Conservation Foundation (WCCF) do not support the Service's assertions
that habitat for the salamanders is threatened by declining water
quality and quantity. New information from water quality studies
performed at nine Georgetown and Jollyville Plateau salamander sites
indicate that aquifer water is remarkably clean and that water quality
protection standards already in place throughout the county are
working.
Our Response: The listing process requires the Service to consider
both ongoing and future threats to the species. Williamson County has
yet to experience the same level of population growth as Travis County,
but is projected to have continued rapid growth in the future.
Therefore, it is not surprising that some areas of Williamson County
may exhibit good water quality, because threats to the Georgetown
salamander or its habitat are primarily from future development.
However, our peer reviewers concluded that the water quality data
referenced by the commenter is not enough evidence to conclude that
water quality at salamander sites in Williamson County is sufficient
(see Comment 19 above). To fully assess the status of salamander
populations and water quality requires long-term monitoring data. The
water samples collected by the WCCF were comprised of a single sample
event consisting of grab samples, so they offer limited insight into
long-term trends in water quality (see Comment 19 above). The best
available science indicates that water quality and species diversity
consistently declines with increasing levels of urban development.
Hydrology
(67) Comment: The Service homogenizes ecosystem characteristics
across the Austin blind, Georgetown, Jollyville Plateau, and Salado
salamanders. The proposed rule often assumes that the ``surface
habitat'' characteristics of the Barton Springs salamander and Austin
blind salamander (year-round surface water in manmade impoundments)
apply to the Salado, Jollyville Plateau, and Georgetown salamanders,
which live in very different geologic and hydrologic habitat. The
Georgetown and Salado salamanders live in water contained within a
``perched'' zone of the Edwards Limestone formation that is relatively
thin and does not retain or recharge much water when compared to the
Barton Springs segment of the Edwards Aquifer. Many of the springs
where the
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Georgetown and Salado salamanders are found are more ephemeral due to
the relatively small drainage basins and relatively quick discharge of
surplus groundwater after a rainfall event. Surface water at several of
the proposed creek headwater critical habitat units is generally short
lived following a rain event. The persistence of Jollyville Plateau,
Georgetown, and Salado salamanders at these headwater locations
demonstrates that the species are not as dependent on surface water as
occupied impoundments suggest.
Our Response: The Service recognizes that the Austin blind
salamander is more subterranean than the other three species of
salamander. However, the Georgetown, Jollyville Plateau, and Salado
salamanders all spend large portions of their lives in subterranean
habitat. Further, the Jollyville Plateau and Georgetown salamanders
have cave-associated forms. There are numerous similarities among all
four of these species. On page 50770 of the proposed rule, the
similarities of these four salamander species are specified. They are
all within the same genus, entirely aquatic throughout each portion of
their life cycles, respire through gills, inhabit water of high quality
with a narrow range of conditions, depend on water from the Edwards
Aquifer, and have similar predators. The Barton Springs salamander
shares these same similarities. Based on this information, the Service
has determined that these species are suitable surrogates for each
other.
Exactly how much these species depend on surface water is unclear,
but the best available information suggests that the productivity of
surface habitat is important for individual growth. For example, a
recent study showed that Jollyville Plateau salamanders had negative
growth in body length and tail width while using subsurface habitat
during a drought and that growth did not become positive until surface
flow returned (Bendik and Gluesenkamp 2012, pp. 3-4). In addition, the
morphological variation found in these salamander populations may
provide insight into how much time is spent in subsurface habitat
compared to surface habitat.
(68) Comment: Another commenter stated that salamander use of
surface habitat is entirely dependent on rainfall events large enough
to generate sufficient spring and stream flow. Even after large
rainfall events, stream flow decreases quickly and dissipates within
days. As a result, the salamanders are predominately underground
species because groundwater is far more abundant and sustainable.
Our Response: See our response to previous comment above.
(69) Comment: Several commenters stated that there is insufficient
data on long-term flow patterns of the springs and creek and on the
correlation of flow, water quality, habitat, ecology, and community
response to make a listing determination. Commenters propose that
additional studies be conducted to evaluate hydrology and surface
recharge area, and water quality.
Our Response: We agree that there is a need for more study on the
hydrology of salamander sites, but there are sufficient available data
on the threats to these species to make a listing determination. We
make our listing determinations based on the five listing factors,
singly or in combination, as described in section 4(a)(1) of the Act.
In making our listing determination, we considered and evaluated the
best available scientific and commercial information.
Pesticides
(70) Comment: Claims of pesticides posing a significant threat are
unsubstantiated. The references cited in the proposed rule are in some
cases misquoted and others are refuted by more robust analysis. The
water quality monitoring reports, as noted in the proposed rule,
indicate that pesticides were found at levels below criteria set in the
aquatic life protection section of the Texas Surface Water Quality
Standards, and they were most often at sites with urban or partly urban
watersheds. This information conflicts with the statement that the
frequency and duration of exposure to harmful levels of pesticides have
been largely unknown or undocumented.
Our Response: We recognize there are uncertainties about the degree
to which different pesticides may be impacting water quality and
salamander health across the range of these salamander species, but the
very nature of pesticides being designed to control unwanted organisms
through toxicological mechanisms and their persistence in the
environment makes them pose an inherent risk to non-target species.
Numerous studies have documented the presence of pesticides in water,
particularly areas impacted by urbanization and agriculture, and there
is ample evidence that full life cycle and multigenerational exposures
to dozens of chemicals, even at low concentrations, contribute to
declines in the abundance and diversity of aquatic species. Few
pesticides or their breakdown products have been tested for
multigenerational effects to amphibians and many do not have an
applicable state or Federal water quality standard. For these reasons,
we maintain that commercial and residential pesticide use contributes
to habitat degradation and poses a threat to the Georgetown and Salado
salamanders, as well as the aquatic organisms that comprise their diet.
(71) Comment: The Service cites Rohr et al. (2003, p. 2,391)
indicating that carbaryl causes mortalities and deformities in
streamside salamanders (Ambystoma barbouri). However, Rohr et al.
(2003, p. 2,391) actually found that larval survival was reduced by the
highest concentrations of carbaryl tested (50 [mu]g/L) over a 37-day
exposure period. Rohr et al. (2003, p. 2,391) also found that embryo
survival and growth was not affected, and hatching was not delayed in
the 37 days of carbaryl exposure. In the same study, exposure to 400
[mu]g/L of atrazine over 37 days (the highest dose tested) had no
effect on larval or embryo survival, hatching, or growth. A Scientific
Advisory Panel (SAP) of the Environmental Protection Agency (EPA)
reviewed available information regarding atrazine effects on
amphibians, including the Hayes (2002) study cited by the Service, and
concluded that atrazine appeared to have no effect on clawed frog
(Xenopus laevis) development at atrazine concentrations ranging from
0.01 to 100 [micro]g/L. These studies do not support the Service's
conclusions.
Our Response: We do not believe that our characterization of Rohr
et al. (2003) misrepresented the results of the study. In their
conclusions, Rohr et al. (2003, p. 2,391) state, ``Carbaryl caused
significant larval mortality at the highest concentration, and produced
the greatest percent of malformed larvae, but did not significantly
affect behavior relative to controls. Although atrazine did not induce
significant mortality, it did seem to affect motor function.'' This
study clearly demonstrates that these two pesticides can have an impact
on amphibian biology and behavior. In addition, the EPA (2007, p. 9)
also found that carbaryl is likely to adversely affect the Barton
Springs salamander both directly and indirectly through reduction of
prey.
Regarding the Hayes (2002) study, we acknowledge that an SAP of the
EPA reviewed this information and concluded that atrazine
concentrations less than 100 [micro]g/L had no effects on clawed frogs
in 2007. However, the 2012 SAP did re-examine the conclusions of the
2007 SAP using a meta-analysis of published studies along with
additional studies on more species (EPA 2012, p. 35). The 2012 SAP
expressed concern that some studies were discounted in
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the 2007 SAP analysis, including studies like Hayes (2002) that
indicated that atrazine is linked to endocrine disruption in amphibians
(EPA 2012, p. 35). In addition, the 2007 SAP noted that their results
on clawed frogs are insufficient to make global conclusions about the
effects of atrazine on all amphibian species (EPA 2012, p. 33).
Accordingly, the 2012 SAP has recommended further testing on at least
three amphibian species before a conclusion can be reached that
atrazine has no effect on amphibians at concentrations less than 100
[micro]g/L (EPA 2012, p. 33). Due to potential differences in species
sensitivity, exposure scenarios that may include dozens of chemical
stressors simultaneously, and multigenerational effects that are not
fully understood, we continue to view pesticides in general, including
carbaryl, atrazine, and many others to which aquatic organisms may be
exposed, as a potential threat to water quality, salamander health, and
the health of aquatic organisms that comprise the diet of salamanders.
Impervious Cover
(72) Comment: One commenter stated that in the draft impervious
cover analysis the Service has provided no data to prove a cause and
effect relationship between impervious cover and the status of surface
salamander sites or the status of underground habitat.
Our Response: Peer reviewers agreed that we used the best available
scientific information in regards to the link between urbanization,
impervious cover, water quality, and salamander populations.
(73) Comment: On page 18 of the draft impervious cover analysis,
the Service dismisses the role and effectiveness of water quality
controls to mitigate the effects of impervious cover: ``. . . the
effectiveness of stormwater runoff measures, such as passive filtering
systems, is largely unknown in terms of mitigating the effects of
watershed-scale urbanization.'' It appears that the Service assumed
that existing water controls have no effect in reducing or removing
pollutants from stormwater runoff. The Service recognized the
effectiveness of such stormwater runoff measures in the final rule
listing the Barton Springs salamander as endangered in 1997. Since
1997, the Service has separately concurred on two occasions that the
water quality controls imposed in the Edwards Aquifer area protect the
Barton Springs salamander and the Georgetown salamander. It is not
appropriate to rely upon generalized findings regarding the
detectability of water quality degradation in watersheds with no water
quality controls.
Our Response: Our analysis within this final rule does not ignore
the effectiveness of water quality control measures. In fact, we
specifically address how these control measures factor into our
analysis under Factor D. We recognize that control measures can reduce
pollution entering bodies of water. However, as presented in our final
impervious cover analysis, data from around the country indicate that
urbanization within the watershed degrades water quality despite the
presence of water quality control measures that have been in place for
decades (Schueler et al. 2009, p. 313). Since 1997, water quality and
salamander counts have declined at several salamander sites within the
City of Austin, as described under Factor A in this final listing rule.
This is in spite of water quality control measures implemented in the
Edwards Aquifer area. Further discussion of these measures can be found
under Factor D of this final listing rule.
(74) Comment: The springshed, as defined in the draft impervious
cover analysis, is a misnomer because the so called springsheds
delineated in the study are not the contributing or recharge area for
the studied springs. Calling a surface area that drains to a specific
stretch of a creek a springshed is disingenuous and probably misleading
to less informed readers.
Our Response: We acknowledge that the term springshed may be
confusing to readers, and we have thus replaced this term with the
descriptors ``surface drainage area of a spring'' or ``surface
watershed of a spring'' throughout this final listing rule and
impervious cover analysis document.
(75) Comment: During the first public comment period, many entities
submitted comments and information directing the Service's attention to
the actual data on water quality in the affected creeks and springs.
Given the amount of water quality data available to the Service and the
public, the Texas Salamander Coalition is concerned that the Service
continues to ignore local data and instead focuses on impervious cover
and impervious cover studies conducted in other parts of the country
without regard to existing water quality regulations. Commenters
questioned why the Service sued models, generic data, and concepts when
actual data on the area of concern is readily available.
Our Response: The Service has examined and incorporated all water
quality data submitted during the public comment periods. However, the
vast majority of salamander sites are still lacking long-term
monitoring data that are necessary to make conclusions on the status of
the site's water quality. The impervious cover analysis allows us to
quantify this specific threat for sites where information is lacking.
Disease
(76) Comment: The Service concludes in the proposed rule that
chytrid fungus is not a threat to any of the salamanders. The Service's
justification for this conclusion is that they have no data to indicate
whether impacts from this disease may increase or decrease in the
future. There appears to be inconsistency in how the information
regarding threats is used.
Our Response: Threats are assessed by their imminence and
magnitude. Currently, we have no data to indicate that chytrid fungus
is a threat to the species. The few studies that have looked for
chytrid fungus in central Texas Eurycea found the fungus, but no
associated pathology was found within several populations and among
different salamander species.
Climate Change
(77) Comment: Climate change has already increased the intensity
and frequency of extreme rainfall events globally (numerous references)
and in central Texas. This increase in rainfall extremes means more
runoff possibly overwhelming the capacity of recharge features. This
has implications for water storage. Implications are that the number of
runoff events recharging the aquifer with a higher concentration of
toxic pollutants than past events will be occurring more frequently,
likely in an aquifer with a lower overall volume of water to dilute
pollutants. Understanding high concentration toxicity needs to be
evaluated in light of this.
Our Response: We agree that climate change will likely result in
less frequent recharge, affecting both water quantity and quality of
springs throughout the aquifer. We have added language in the final
listing rule to further describe the threat of climate change and
impacts to water quality.
(78) Comment: The section of the proposed rule addressing climate
change fails to include any consideration or description of a baseline
central Texas climate. The proposed rule describes flooding and drought
as threats, but fails to provide any serious contextual analysis of the
role of droughts and floods in the life history of the central Texas
salamanders.
Our Response: The proposed and final listing rules discuss the
threats of
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drought conditions and flooding, both in the context of naturally
occurring weather patterns and as a result of anthropogenic activities.
(79) Comment: The flooding analysis is one of several examples in
the proposed rule in which the Service cites events measured on micro-
scales of time and area, and fails to comprehend the larger ecosystem
at work. For example, the proposed rule describes one flood event
causing ``erosion, scouring the streambed channel, the loss of large
rocks, and creation of several deep pools.'' Later, the Service
describes other flooding events as depositing sediment and other
materials on spring openings at Salado Spring (page 50788). Scouring
and depositing sediment are both normal results of the intense rainfall
events in central Texas.
Our Response: While we agree that scouring and sediment deposition
are normal hydrologic processes, when the frequency and intensity of
these events is altered by climate change, urbanization, or other
anthropogenic forces, the resulting impacts to ecosystems can be more
detrimental than what would occur naturally.
Other Threats
(80) Comment: The risk of extinction is negatively or inversely
correlated with population size. Also, small population size, in and of
itself, can increase the risk of extinction due to demographic
stochasticity, mutation accumulation, and genetic drift. The
correlation between extinction risk and population size is not
necessarily indirect (that is, due to an additional extrinsic factor
such as environmental perturbation).
Our Response: Although we do not consider small population sizes to
be a threat in and of itself to either the Georgetown or Salado
salamander, we do conclude that small population sizes make them more
vulnerable to extinction from other existing or potential threats, such
as major stochastic events.
Water Quality
(81) Comment: The City of Georgetown's Unified Development Code
requires that all development in this territory, including projects
less than 1 ac (0.4 ha), must meet all requirements of the TCEQ for
water quality. For commercial sites, the City of Georgetown's Unified
Development Code allows a maximum of 70 percent impervious cover for
tracts less than 5 ac (2 ha). For tracts greater than 5 ac (2 ha), the
Unified Development Code allows 70 percent impervious cover for the
first 5 ac (2 ha), and then 55 percent impervious cover over the
initial 5 ac (2 ha). The Unified Development Code also allows the area
above the initial 5 ac (2 ha) to be upgraded to 70 percent impervious
with advanced water quality. The required advanced water-quality
systems are retention irrigation, removing 100 percent of the suspended
solids; wet ponds, removing 93 percent suspended solids; or
bioretention facilities, removing 89 percent suspended solids. For
residential projects, the City of Georgetown's Unified Development Code
allows a maximum of 45 percent impervious cover.
Our Response: We recognize and agree that best management
practices, such as the development codes mentioned by the commenter,
provide some protection to water quality. However the protections are
not effective in alleviating all the threat of degraded water quality
for any of the salamanders. On-site retention of storm flows and other
regulatory mechanisms to protect water quality are beneficial and work
well to remove certain types of pollutants such as total dissolved
solids, but in most cases, habitat quality in urban environments still
degrades over time due to persistent pollutants like trace metals and
pesticides that can accumulate in sediments and biological tissues.
(82) Comment: The Service should have consulted with those federal
and state agencies that are charged with protecting water quality and
that have the expertise to address water quality issues. The EPA, TCEQ,
and the USGS are experts on the reliability of the water quality
studies cited by the Service in its determination that water quality in
central Texas continues to decline.
Our Response: We notified and invited the EPA, TCEQ, and USGS to
comment on our proposed rule and provide any data on water quality
within the range of the salamander species. Two USGS biologists
provided peer reviews on our proposed rule, and we cited numerous
studies from the EPA, TCEQ, and USGS in our final analysis.
Taxonomy
(83) Comment: The level of genetic divergence among the Jollyville
Plateau, Georgetown, and Salado salamanders is not sufficiently large
to justify recognition of three species. The DNA papers indicate a
strong genetic relationship between individual salamanders found across
the area. Such a strong relationship necessarily means that on an
ecosystem wide basis, the salamanders are exchanging genetic material
on a regular basis. There is no evidence that any of these salamanders
are unique species.
Our Response: The genetic relatedness of the three northern species
(Georgetown salamander, Jollyville Plateau salamander, and Salado
salamanders) is not disputed. The three species are included together
on a main branch of the tree diagrams of mtDNA data (Chippindale et al.
2000, Figs. 4 and 6). The tree portraying relationships based on
allozymes (genetic markers based on differences in proteins coded by
genes) is concordant with the mtDNA trees (Chippindale et al. 2000,
Fig. 5). These trees support the evolutionary relatedness of the three
species, but not their identity as a single species. The lack of
sharing of mtDNA haplotype markers, existence of unique allozyme
alleles in each of the three species, and multiple morphological
characters diagnostic of each of the three species are inconsistent
with the assertion that they are exchanging genetic material on a
regular basis. The Austin blind salamander is on an entirely different
branch of the tree portraying genetic relationships among these species
based on mtDNA, and has diagnostic, morphological characters that
distinguish it from other Texas salamanders (Hillis et al. 2001, p.
267). Based on our review of these differences, and taking into account
the view expressed in peer reviews by taxonomists, we conclude that the
currently available evidence is sufficient for recognizing these
salamanders as four separate species.
(84) Comment: A genetics professor commented that Forstner's report
(2012) disputing the taxonomy of the four central Texas salamanders
represents a highly flawed analysis that has not undergone peer review.
It is not a true taxonomic analysis of the Eurycea complex and does not
present any evidence that call into question the current taxonomy of
the salamanders. Forstner's (2012) report is lacking key information
regarding exact methodology and analysis. It is not entirely clear what
resulting length of base pairs was used in the phylogenetic analysis
and the extent to which the data set was supplemented with missing or
ambiguous data. The amount of sequence data versus missing data is
important for understanding and interpreting the subsequent analysis.
It also appears as though Forstner included all individuals with
available, unique sequence when, in fact, taxonomic sampling--that is,
the number of individuals sampled within a particular taxon compared
with other taxa--can also affect the accuracy of the resulting
topology. The Forstner (2012)
[[Page 10255]]
report only relies on mitochondrial DNA whereas the original taxonomic
descriptions of these species relied on a combination of nuclear DNA,
mitochondrial DNA as well as morphology (Chippindale et al. 2000,
Hillis et al. 2001). Forstner's (2012) report does not consider non-
genetic factors such as ecology and morphology when evaluating
taxonomic differences. Despite the limitations of a mitochondrial DNA-
only analysis, Forstner's (2012) report actually contradicts an earlier
report by the same author that also relied only on mtDNA.
Our Response: This comment supports the Service's and our peer
reviewers' interpretation of the best available data (see responses to
comments 1 through 6 above).
(85) Comment: Forstner (2012) argues that the level of genetic
divergence among the three species of Texas Eurycea is not sufficiently
large to justify recognition of three species. A genetics professor
commented that this conclusion is overly simplistic. It is not clear
that the populations currently called Eurycea lucifuga in reality
represent a single species, as Forstner (2012) assumes. Almost all
cases of new species in the United States for the last 20 years (E.
waterlooensis is a rare exception) have resulted from DNA techniques
used to identify new species that are cryptic, meaning their similarity
obscured the genetic distinctiveness of the species. One could view the
data on Eurycea lucifuga as supporting that cryptic species are also
present. Moreover, Forstner's (2012) comparison was made to only one
species, rather than to salamanders generally. Moreover, there is
perhaps a problem with the Harlan and Zigler (2009) data. They
sequenced 10 specimens of E. lucifuga, all from Franklin County,
Tennessee; 9 of these show genetic distances between each other from
0.1 to 0.3 percent, which is very low. One specimen shows genetic
distance to all other nine individuals from 1.7 to 1.9 percent, an
order of magnitude higher. This single specimen is what causes the high
level of genetic divergence to which Forstner compares the Eurycea.
This discrepancy is extremely obvious in the Harlan and Zigler (2009)
paper, but was not mentioned by Forstner (2012). A difference of an
order of magnitude in 1 specimen of 10 is highly suspect, and,
therefore, these data should not be used as a benchmark in comparing
Eurycea.
The second argument in Forstner (2012) is that the phylogenetic
tree does not group all individuals of a given species into the same
cluster or lineage. Forstner's (2012) conclusions are overly
simplistic. The failure of all sequences of Eurycea tonkawae to cluster
closely with each other is due to the amount of missing data in some
sequences. It is well known in the phylogenetics literature that
analyzing sequences with very different data (in other words, large
amounts of missing data) will produce incorrect results because of this
artifact. As an aside, why is there missing data? The reason is that
these data were produced roughly 5 years apart. The shorter sequences
were made at a time when lengths of 350 bases for cytochrome b were
standard because of the limitations of the technology. As improved and
cheaper methods were available (about 5 to 6 years later), it became
possible to collect sequences that were typically 1,000 to 1,100 bases
long. It is important to remember that the data used to support the
original description of the three northern species by Chippindale et
al. (2000) were not only cytochrome b sequences, but also data from a
different, but effective, analysis of other genes, as well as analysis
of external characteristics. Forstner's (2012) assessment of the
taxonomic status (species or not) of the three species of the northern
group is not supported by the purported evidence that he presents (much
of it unpublished).
Our Response: This comment supports the Service's and our peer
reviewers' interpretation of the best available data (see Responses to
Comments 1 through 5 above)
(86) Comment: Until the scientific community determines the
appropriate systematic approach to identify the number of species, it
seems imprudent to elevate the salamanders to endangered.
Our Response: The Service must base its listing determinations on
the best available scientific and commercial information, and such
information includes considerations of correct taxonomy. To ensure the
appropriateness of our own analysis of the relevant taxonomic
literature, we sought peer reviews from highly qualified taxonomists,
particularly with specialization on salamander taxonomy, of our
interpretation of the available taxonomic literature and unpublished
reports. We find that careful analysis and peer review is the best way
to determine whether any particular taxonomic arrangement is likely to
be generally accepted by experts in the field. The peer reviews that we
received provide overall support, based on the available information,
for the species that we accept as valid in the final listing rule.
Technical Information
(87) Comment: The Service made the following statement in the
proposed rule: ``Therefore, the status of subsurface populations is
largely unknown, making it difficult to assess the effects of threats
on the subsurface populations and their habitat.'' In fact, the
difficulty of assessing threats for subsurface populations depends upon
the threats. One can more easily assess threats of chemical pollutants,
for example, because subterranean populations will be affected
similarly to surface ones because they inhabit the same or similar
water.
Our Response: The statement above was meant to demonstrate the
problems associated with not knowing how many salamanders exist in
subsurface habitat rather than how threats are identified. We have
removed the statement in the final listing rule to eliminate this
confusion.
City of Georgetown's Water Quality Ordinance
(88) Comment: Several comments supported the City of Georgetown's
Edwards Aquifer Recharge Zone Water Quality Ordinance that was adopted
by the Georgetown City Council on December 20, 2013. These commenters
stated that regulations to protect the Georgetown salamander are better
implemented at the local level compared to Federal regulations.
Our response: The Service appreciates the effort put forth by the
City of Georgetown and Williamson County to help reduce threats to the
Georgetown salamander through the implementation of their Edwards
Aquifer Recharge Zone Water Quality Ordinance. Section 4(b)(1)(A) of
the Act requires us to take into account those efforts being made by a
state or foreign nation, or any political subdivision of a state or
foreign nation, to protect such species. We also consider relevant
Federal and tribal laws and regulations in our threats analysis. In our
analysis, we consider whether or not existing regulatory mechanisms are
adequate enough to address the threats to the species such that listing
is no longer warranted. For further discussion of existing regulations
and ordinances, please see Factors A and D below in this final listing
rule.
(89) Comment: The combination of plans and promises put forward by
the City of Georgetown lack any true staying power and their
effectiveness seems largely up to the willingness of all interested
parties to cooperate on a voluntary basis. Importantly, the rules and
suggested development practices
[[Page 10256]]
laid out in the Edwards Aquifer Recharge Zone Water Quality Ordinance
and Georgetown Water Quality Management Plan make little mention of the
business of granting exceptions. The WCCF is a non-profit corporation
with strong allies in for-profit corporations. It is entirely within
the realm of reasonable possibility that trusting the front of the WCCF
to guide city policy instead would mask a for-profit pro-development
agenda. In fact, the City Ordinance 2013-59 makes explicit the City
Council's priority ``[. . .] to ensure that future growth and
development is unbridled by potential Federal oversight nor Federal
permitting requirements that would delay development projects
detrimentally to the sustained viability of the city's economy [. .
.].'' In this area, I am most concerned such that the real ``teeth'' of
the plans rests in the ability of the City of Georgetown to obtain and
keep what is almost entirely voluntary compliance.
Our response: The City of Georgetown's Edwards Aquifer Recharge
Zone Water Quality Ordinance was adopted by the Georgetown City Council
on December 20, 2013, and became effective immediately. All regulated
activities within the City of Georgetown and its extraterritorial
jurisdiction (ETJ) located over the recharge zone are required to
implement the protective measures established by the ordinance.
Compliance with the ordinance is not voluntary. The ordinance also
established an Adaptive Management Working Group to review Georgetown
salamander monitoring data and new research over time and recommending
improvements to the ordinance that may be necessary to ensure that it
achieves its stated purposes. This Adaptive Management Working Group,
which includes representatives of the Service and TPWD, will also
review and make recommendations on the approval of any variances to the
ordinance.
(90) Comment: Once the Federal government passes control to a local
government entity, any protection provided to the salamander will
eventually disappear.
Our response: The Service supports local involvement and interest
in the conservation of salamanders. Section 4(b)(1)(A) of the Act
requires us to take into account those efforts being made by a state or
foreign nation, or any political subdivision of a state or foreign
nation, to protect such species, and we fully recognize the
contributions of local programs.
(91) Comment: Several commenters stated that the City of Georgetown
ordinance does not fully alleviate known threats to the Georgetown
salamander and will not significantly reduce its danger of extinction.
They acknowledged that the ordinance could provide minor protections to
certain aspects of water quality in the immediate vicinity of occupied
spring sites, such as to decrease the probability of wholesale
destruction by physical disturbance of occupied springs. But, the
commenters stated that the ordinance would not protect the quantity of
spring flows or threats to water quality from more distant points in
the spring watersheds. Further, they noted that the ordinance does not
address the threats from small population size, drought, or climate
change.
(92) Comment: The buffer zones described in the ordinance lessen
the potential for further water quality degradation, but they do not
remove the threat posed by existing development. Four Georgetown
salamander sites are located in areas where the impervious cover
estimates exceed thresholds where harm to water quality is expected to
occur. The threat of chemical spills from existing highways, sewer
lines, and septic systems still exists. Existing development has
already affected salamander habitat and degradation will continue with
new development.
(93) Comment: The City of Austin Save Our Springs Ordinance is a
non-degradation ordinance that requires 100 percent removal of total
suspended solids (TSS). Despite this, the City of Austin rules were not
sufficient to preclude the 2013 listing of the Austin Blind Salamander.
Because it requires only 85 percent removal of TSS, the City of
Georgetown's water quality ordinance is substantially less protection
than the City of Austin's. Thus, it would be inconsistent for the
Service to preclude listing of the Georgetown Salamander on this basis.
(94) Comment: The City of Georgetown ordinance does not specify a
prohibition on sediment discharge during the critical ground-disturbing
construction phase of new development, and no performance criteria for
sediment removal are specified. Thus, the ordinance is insufficient to
eliminate sedimentation of salamander habitat as a result of new
development construction.
(95) Comment: In addition to the impacts from existing development
that would continue under the Georgetown ordinance, projects that were
platted or planned prior to the Georgetown ordinance would not be
subject to the new ordinance as exempted under Chapter 245
``grandfathering'' provisions of Texas State law. Five Georgetown
salamander sites are exempt from the requirements of the Georgetown
ordinance (Cowan Spring, Bat Well Cave, Water Tank Cave, Knight Spring,
and Shadow Canyon Spring). The development near Shadow Canyon Spring is
currently under consultation with the Service, while the four other
sites are all compliant with the Red Zone as described in the
ordinance. Because current TCEQ development regulations require removal
of 80 percent TSS for every project within the recharge zone of the
Edwards Aquifer as opposed to the 85 percent TSS removal required in
the new ordinance, the overall effect on the water quality of the
Edwards Aquifer from these four small sites is minimal.
(96) Comment: The Georgetown ordinance does not include impervious
cover limitations in the upstream surface water or groundwater
contributing areas to salamander habitat. The effectiveness and
protectiveness of the flood and water quality controls included in the
Georgetown ordinance decrease with increasing impervious cover.
(97) Comment: The City of Georgetown and Williamson County have
continually demonstrated their ongoing commitment to establishing and
implementing programs to preserve open space, protect species habitat
and reduce dependence on groundwater water supplies. The success of
these programs to protect endangered karst dwelling invertebrates and
songbirds highlights the willingness and intention to implement and
enforce the recently approved Georgetown salamander ordinances. The
successful working relationship established between Williamson County
and the Service also speaks to the likelihood of implementation. In
addition, the City of Georgetown staffs a code enforcement division
responsible for monitoring both public and private property, commercial
and residential, to ensure compliance with all city codes and
ordinances. The City of Georgetown has successfully implemented water
quality regulations within its jurisdiction in the past.
(98) Comment: The certainty of effectiveness of the ordinance is
increased by the formation of an Adaptive Management Working Group and
an Adaptive Management Plan charged specifically with reviewing
salamander monitoring data and new research over time and recommending
improvements to the ordinance that may be necessary to ensure that it
achieves its stated purposes. This Adaptive Management Working Group,
which includes representatives of the Service and TPWD, will also
review and make
[[Page 10257]]
recommendations on the approval of any variances to the ordinance.
Our response to Comments 91-98: The Service has analyzed the effect
of the ordinance on the threats identified below under Summary of
Factors Affecting the Species and have made a determination as to
whether or not the regulatory mechanism (City of Georgetown ordinance)
has reduced the threats to the point that listing the species as
threatened or endangered under the Act is no longer warranted.
(99) Comment: The Red Zone buffer should extend past culverts and
roadways because these are not documented impediments to salamander
migration.
Our response: The ordinance specifically states that the Red Zone
``. . . shall not extend beyond any existing physical obstructions that
prevent the surface movement of Georgetown salamanders . . .''
Therefore, the Service believes that any physical obstructions that do
not prevent the surface movement of salamanders would not be included
as limiting the size of the Red Zone.
(100) Comment: Development activities within the contributing area
of the spring outside of the 984-ft (300-m) buffer of the Orange Zone
would still affect the quality and quantity of spring discharge.
Our response: The Service agrees that some activities occurring
further than 984 ft (300 m) from a spring site could have the potential
to impact the quality and quantity of spring discharge. However,
overall, we believe that the ordinance has minimized and reduced some
of the threats to the Georgetown salamander. See the discussion below
under Summary of Factors Affecting the Species.
(101) Comment: While the City of Georgetown has expressed its
intention to rely upon surface water or wells outside the Edwards
Aquifer for additional future water supplies, these intentions are
purely voluntary and cannot be considered sufficient to remove the
threat of inadequate spring flows.
Our response: The Service does not consider the City of
Georgetown's intention to rely upon surface water or wells outside the
Edwards Aquifer sufficient to entirely remove the threat of inadequate
spring flows.
Summary of Changes From the Proposed Rule
Based upon our review of the public comments, comments from other
Federal and State agencies, peer review comments, issues addressed at
the public hearing, and any new relevant information that may have
become available since the publication of the proposal, we reevaluated
our proposed rule and made changes as appropriate. The Service has
incorporated information related to the Edwards Aquifer Recharge Zone
Water Quality Ordinance approved by the Georgetown City Council on
December 20, 2013 (Ordinance No. 2013-59). The purpose of this
ordinance is to reduce some of the threats to the Georgetown salamander
within the City of Georgetown and its ETJ through the protection of
water quality near occupied sites known at the time the ordinance was
approved, enhancement of water quality protection throughout the
Edwards Aquifer recharge zone, and establishment of protective buffers
around all springs and streams. Additionally, an Adaptive Management
Working Group has been established that is charged specifically with
reviewing Georgetown salamander monitoring data and new research over
time and recommending improvements to the ordinance that may be
necessary to ensure that it achieves its stated purposes. This Adaptive
Management Working Group, which includes representatives of the Service
and TPWD, will also review and make recommendations on the approval of
any variances to the ordinance.
During the two comment periods that were opened during the 6-month
extension, the Service did not receive any additional information to
assist us in making a conclusion regarding the population trends of
either of these two species. However, a report submitted by the
Williamson County Conservation Foundation noted that since April 2012
biologists have observed Georgetown salamanders at Swinbank Spring and
Twin Springs (Pierce and McEntire 2013, p. 8). These two sites and one
additional site (Cowan Spring) are the only Georgetown salamander
locations for which population surveys have been conducted over
multiple years. We are not aware of any population trend analysis that
has been conducted for the Georgetown salamander. Dr. Toby Hibbits
conducted surveys for the Salado salamander at nine different locations
during the fall of 2013 and was unable to locate any salamanders. He
concluded ``. . . even in the best conditions that Salado Salamanders
are difficult to find and likely occupy the surface habitat in low
numbers'' (Hibbits 2013, p. 3). Therefore, we are not making any
conclusions related to the short- and long-term population trends of
the Georgetown or Salado salamanders in this final rule.
Finally, in addition to minor clarifications and incorporation of
additional information on the species' biology and related to the new
Georgetown water quality ordinance, this determination differs from the
proposal because, based on our analyses, the Service has determined
that the Georgetown and Salado salamanders should be listed as
threatened species instead of endangered species.
Summary of Factors Affecting the Species
Section 4 of the Act and its implementing regulations (50 CFR 424)
set forth the procedures for adding species to the Federal Lists of
Endangered and Threatened Wildlife and Plants. A species may be
determined to be an endangered or threatened species due to one or more
of the five factors described in section 4(a)(1) of the Act: (A) The
present or threatened destruction, modification, or curtailment of its
habitat or range; (B) overutilization for commercial, recreational,
scientific, or educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; or (E) other natural or
manmade factors affecting its continued existence. Listing actions may
be warranted based on any of the above threat factors, singly or in
combination. Each of these factors is discussed below.
In considering what factors might constitute threats, we must look
beyond the mere exposure of the species to the factor to determine
whether the species responds to the factor in a way that causes actual
impacts to the species. If there is exposure to a factor, but no
response, or only a positive response, that factor is not a threat. If
there is exposure and the species responds negatively, the factor may
be a threat and we then attempt to determine how significant a threat
it is. If the threat is significant, it may drive or contribute to the
risk of extinction of the species such that the species warrants
listing as endangered or threatened as those terms are defined by the
Act. This does not necessarily require empirical proof of a threat. The
combination of exposure and some corroborating evidence of how the
species is likely impacted could suffice. The mere identification of
factors that could impact a species negatively is not sufficient to
compel a finding that listing is appropriate; we require evidence that
these factors are operative threats that act on the species to the
point that the species meets the definition of an endangered or
threatened species under the Act.
[[Page 10258]]
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Habitat modification, in the form of degraded water quality and
quantity and disturbance of spring sites, is the primary threat to the
Georgetown and Salado salamanders. Water quality degradation in
salamander habitat has been cited in several studies as the top concern
for closely related salamander species in the central Texas region
(Chippindale et al. 2000, pp. 36, 40, 43; Hillis et al. 2001, p. 267;
Bowles et al. 2006, pp. 118-119; O'Donnell et al. 2006, pp. 45-50). The
Georgetown and Salado salamanders spend their entire life cycle in
water. They have evolved under natural aquifer conditions both
underground and as the water discharges from natural spring outlets.
Deviations from high water quality and quantity have detrimental
effects on salamander ecology because the aquatic habitat can be
rendered unsuitable for salamanders by changes in water chemistry and
flow patterns. Substrate modification is also a major concern for
aquatic salamander species (City of Austin (COA) 2001, pp. 101, 126;
Geismar 2005, p. 2; O'Donnell et al. 2006, p. 34). Unobstructed
interstitial space is a critical component to the surface habitat for
both the Georgetown and Salado salamander species, because it provides
cover from predators and habitat for their macroinvertebrate prey items
within surface sites. When the interstitial spaces become compacted or
filled with fine sediment, the amount of available foraging habitat and
protective cover for salamanders with these behaviors is reduced,
resulting in population declines (Welsh and Ollivier 1998, p. 1,128;
Geismar 2005, p. 2; O'Donnell et al. 2006, p. 34).
Threats to the habitat of the Georgetown and Salado salamanders
(including those that affect water quality, water quantity, or the
physical habitat) may affect only the surface habitat, only the
subsurface habitat, or both habitat types. For example, substrate
modification degrades the surface springs and spring-runs but does not
impact the subsurface environment within the aquifer, while water
quality degradation can impact both the surface and subsurface
habitats, depending on whether the degrading elements are moving
through groundwater or are running off the ground surface into a spring
area (surface watershed). Our assessment of water quality threats from
urbanization is largely focused on surface watersheds because of the
limited information available on subsurface flows and drainage areas
that feed into the spring and cave locations. An exception to this
would be threats posed by chemical pollutants to water quality, which
would negatively impact both surface and subsurface habitats. These
recharge areas are additional pathways for impacts to the Georgetown
and Salado salamanders to happen that we are not able to precisely
assess at each known salamander site. However, we can consider
urbanization and various other sources of impacts to water quality and
quantity over the larger recharge zone to the aquifer (as opposed to
individual springs) to assess the potential for impacts at salamander
sites.
The threats under Factor A will be presented in reference to
stressors and sources. We consider a stressor to be a physical,
chemical, or biological alteration that can induce an adverse response
from an individual salamander. These alterations can act directly on an
individual or act indirectly on an individual through impacts to
resources the species requires for feeding, breeding, or sheltering. A
source is the origin from which the stressor (or alteration) arises.
The majority of the discussion below under Factor A focuses on
evaluating the nature and extent of stressors and their sources related
to urbanization, the primary source of water quality degradation,
within the ranges of the Georgetown and Salado salamander species.
Additionally, other stressors causing habitat destruction and
modification, including water quantity degradation and physical
disturbance to surface habitat, will be addressed.
Throughout the threats discussion below, we have provided
references to studies or other information available in our files that
evaluate threats to the Georgetown and Salado salamanders that are
occurring or are likely to occur in the future given the considerable
human population growth that is projected for the areas known to be
occupied by these species. Establishing causal relationships between
environmental stressors and observed effects in organisms is difficult
because there are no widely accepted and proven approaches for
determining such relationships and because experimental studies (either
in the laboratory or the field) on the effects of each stressor on a
particular organism are rare.
In the field of aquatic ecotoxicology, it is common practice to
apply the results of experiments on common species to other species
that are of direct interest (Caro et al. 2005, p. 1,823). In addition,
the field of conservation biology is increasingly relying on
information about substitute species to predict how related species
will respond to stressors (for example, see Caro et al. 2005 pp. 1,821-
1,826; Wenger 2008, p. 1,565). In instances where information was not
available for the Georgetown and Salado salamander specifically, we
have provided references for studies conducted on similarly related
species, such as the Jollyville Plateau salamander (Eurycea tonkawae)
and Barton Springs salamander (Eurycea sosorum), which occur within the
central Texas area, and other salamander species that occur in other
parts of the United States. The similarities among these species may
include: (1) A clear systematic (evolutionary) relationship (for
example, members of the Family Plethodontidae); (2) shared life-history
attributes (for example, the lack of metamorphosis into a terrestrial
form); (3) similar morphology and physiology (for example, the lack of
lungs for respiration and sensitivity to environmental conditions); (4)
similar prey (for example, small invertebrate species); and (5) similar
habitat and ecological requirements (for example, dependence on aquatic
habitat in or near springs with a rocky or gravel substrate). Depending
on the amount and variety of characteristics in which one salamander
species can be analogous to another, we used these similarities as a
basis to infer further parallels in how a species or population may
respond or be affected by a particular source or stressor.
Water Quality Degradation
Urbanization
Urbanization is one of the most significant sources of water
quality degradation that can reduce the survival of aquatic organisms,
such as the Georgetown and Salado salamanders (Bowles et al. 2006, p.
119; Chippindale and Price 2005, pp. 196-197). Urban development leads
to various stressors on spring systems, including increased frequency
and magnitude of high flows in streams, increased sedimentation,
increased contamination and toxicity, and changes in stream morphology
and water chemistry (Coles et al. 2012, pp. 1-3, 24, 38, 50-51).
Urbanization can also impact aquatic species by negatively affecting
their invertebrate prey base (Coles et al. 2012, p. 4). Urbanization
also increases the sources and risks of an acute or catastrophic
contamination event, such as a leak from an underground storage tank or
a hazardous materials spill on a highway.
Rapid human population growth is occurring within the ranges of the
Georgetown and Salado salamanders.
[[Page 10259]]
The Georgetown salamander's range is located within an increasingly
urbanized area of Williamson County, Texas (Figure 1). In 2010, the
human population within the City of Georgetown's extraterritorial
jurisdiction was 68,821 (City of Georgetown 2013, p. 3). By one
estimate, this population is expected to exceed 225,000 by 2033 (City
of Georgetown 2008, p. 3.5), which would be a 227 percent increase over
a 23-year period. Another model projects that the City of Georgetown
population will increase to 135,005 by 2030, a 96 percent increase over
the 20-year period. The Texas State Data Center (2012, pp. 166-167)
estimates an increase in human population in Williamson County from
422,679 in 2010, to 2,015,294 in 2050, exceeding the human population
size of adjacent Travis County where the City of Austin metropolitan
area is located. This would represent a 377 percent increase over a 40-
year timeframe. Population projections from the Texas State Data Center
(2012, p. 353) estimate that Bell County, where the Salado salamander
occurs, will increase in population from 310,235 in 2010 to 707,840 in
2050, a 128 percent increase over the 40-year period. By comparison,
the national United States' population is expected to increase from
310,233,000 in 2010 to 439,010,000 in 2050, which is about a 42 percent
increase over the 40-year period (U.S. Census Bureau 2008, p. 1).
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Growing human population sizes increase demand for residential and
commercial development, drinking water supply, flood control, and other
municipal foods and services that alter the environment, often
degrading salamander habitat by changing hydrologic regimes and
decreasing the quantity and quality of water resources (Coles et al.
2012, pp. 9-10). As development increases within the watersheds where
the Georgetown and Salado salamanders occur, more opportunities exist
for the detrimental effects of urbanization to impact salamander
habitat without further conservation measures. A comprehensive study by
the USGS found that across the United States contaminants, habitat
destruction, and increasing stream flow flashiness (rapid response of
large increases of stream flow to storm events) resulting from
[[Page 10261]]
urban development have been associated with the disruption of
biological communities, particularly the loss of sensitive aquatic
species (Coles et al. 2012, p. 1).
Several researchers have examined the negative impact of
urbanization on stream salamander habitat by making connections between
salamander abundances and levels of development within the watershed.
In a 1972 study on the dusky salamander (Desmognathus fuscus) in
Georgia, Orser and Shure (p. 1,150) were among the first biologists to
show a decrease in stream salamander density with increasing urban
development. A similar relationship between salamander populations and
urbanization was found in another study on the dusky salamander, two-
lined salamander (Eurycea bislineata), southern two-lined salamander
(Eurycea cirrigera), and other species in North Carolina (Price et al.
2006, pp. 437-439; Price et al. 2012a, p. 198), Maryland, and Virginia
(Grant et al. 2009, pp. 1,372-1,375). Willson and Dorcas (2003, pp.
768-770) demonstrated the importance of examining disturbance within
the entire watershed as opposed to areas just adjacent to the stream by
showing that salamander abundance in the dusky and two-lined
salamanders is most closely related to the amount and type of habitat
within the entire watershed. In central Texas, Bowles et al. (2006, p.
117) found lower Jollyville Plateau salamander densities in tributaries
with developed watersheds as compared to tributaries with undeveloped
watersheds. Developed tributaries also had higher concentrations of
chloride, magnesium, nitrate-nitrogen, potassium, sodium, and sulfate
(Bowles et al. 2006, p. 117). Because of the similarities in size,
morphology, habitat requirements, and life history traits shared with
the dusky salamander, two-lined salamander, southern two-lined
salamander, and Jollyville Plateau salamander, we expect development
occurring within the Georgetown and Salado salamanders' watersheds to
affect these species in a similar manner.
The impacts that result from urbanization can affect the physiology
of individual salamanders. An unpublished study has demonstrated that
Jollyville Plateau salamanders in disturbed habitats have greater
stress levels than those in undisturbed habitats, as determined by
measurements of water-borne stress hormones in urbanized (approximately
25 percent impervious cover within the watershed) and undisturbed
streams (Gabor 2012, Texas State University, pers. comm.). Chronic
stress can decrease survival of individuals and may lead to a decrease
in reproduction. Both of these factors may partially account for the
decrease in abundance of salamanders in streams within disturbed
environments (Gabor 2012, Texas State University, pers. comm.). Because
of the similarities in morphology, physiology, habitat requirements,
and life history traits shared with the Jollyville Plateau salamander,
we expect chronic stress in disturbed environments to decrease
survival, reproduction, and abundance of Georgetown and Salado
salamanders.
Urbanization occurring within the watersheds of the Georgetown and
Salado salamanders has the potential to cause irreversible declines or
extirpation of salamander populations with continuous exposure to its
effects (such as, contaminants, changes in water chemistry, and changes
in stream flow) over a relatively short time span. Although surface
watersheds for the Georgetown and Salado salamander are not as
developed as that of the Jollyville Plateau salamander at the present
time, it is likely that impacts from this threat will increase in the
future as urbanization expands within the surface watersheds for these
species as well.
Impervious cover is another source of water quality degradation and
is directly correlated with urbanization (Coles et al. 2012, p. 38).
For this reason, impervious cover is often used as a surrogate
(substitute) measure for urbanization (Schueler et al. 2009, p. 309).
Impervious cover is any surface material that prevents water from
filtering into the soil, such as roads, rooftops, sidewalks, patios,
paved surfaces, or compacted soil (Arnold and Gibbons 1996, p. 244).
Once vegetation in a watershed is replaced with impervious cover,
rainfall is converted to surface runoff instead of filtering through
the ground (Schueler 1991, p. 114). Impervious cover in a watershed has
the following effects: (1) It alters the hydrology or movement of water
through a watershed, (2) it increases the inputs of contaminants to
levels that greatly exceed those found naturally in streams, and (3) it
alters habitats in and near streams that provide living spaces for
aquatic species (Coles et al. 2012, p. 38), such as the Georgetown and
Salado salamanders and their prey. During periods of high precipitation
levels in highly urbanized areas, stormwater runoff enters recharge
areas of the Edwards Aquifer and rapidly transports sediment,
fertilizer nutrients, and toxic contaminants (such as pesticides,
metals, and petroleum hydrocarbons) to salamander habitat (COA 1990,
pp. 12-14). The Adaptive Management Working Group will monitor data and
new research over time and recommend improvements to the Ordinance that
may be necessary to ensure that it achieves its stated purposes to
maintain the Georgetown salamander at its current or improved status.
Both nationally and locally, consistent relationships between
impervious cover and water quality degradation through contaminant
loading have been documented. Stormwater runoff loads were found to
increase with increasing impervious cover in a study of contaminant
input from various land use areas in Austin, Texas (COA 1990, pp. 12-
14). This study also found that contaminant input rates of the more
urbanized watersheds were higher than those of the small suburban
watersheds (COA 1990, pp. 12-14). Stormwater contaminant loading is
positively correlated with development intensity in Austin (Soeur et
al. 1995, p. 565). Several different contaminant measurements were
found to be positively correlated with impervious cover (5-day
biochemical oxygen demand, chemical oxygen demand, ammonia, dissolved
phosphorus, copper, lead, and zinc) in a study of 38 small watersheds
in the Austin area (COA 2006, p. 35). Using stream data from 1958 to
2007 at 24 Austin-area sites, the COA's water quality index
demonstrated a strong negative correlation with impervious cover (Glick
et al. 2009, p. 9). Mean concentrations of most water quality
constituents, such as total suspended solids and other pollutants, are
lower in undeveloped watersheds than those for urban watersheds
(Veenhuis and Slade 1990, pp. 18-61).
Impervious cover has demonstrable impacts on biological communities
within streams. Sites receiving runoff from high impervious cover
drainage areas lose sensitive aquatic macroinvertebrate species, which
are replaced by species more tolerant of pollution and hydrologic
stress (high rate of changes in discharges over short periods of time)
(Schueler 1994, p. 104). Considerable losses of algal, invertebrate,
and fish species in response to stressors brought about by urban
development were documented in an analysis of nine regions across the
United States (Coles et al. 2012, p. 58). Additionally, a strong
negative relationship between impervious cover and the abundance of
larval southern two-lined salamander (Eurycea cirrigera) was found in
an analysis of 43 North Carolina streams (Miller et al. 2007, pp. 78-
79).
[[Page 10262]]
Like the Georgetown and Salado salamanders, larval (juveniles that
are strictly aquatic) southern two-lined salamanders are entirely
aquatic salamanders within the family Plethodontidae. They are also
similar to the Georgetown and Salado salamanders in morphology,
physiology, size, and habitat requirements. Given these similarities,
we expect a negative relationship between the abundance of Georgetown
and Salado salamanders and impervious cover within the surface
watersheds of these species as human population growth and development
increase.
To reduce the stressors associated with impervious cover, the City
of Georgetown recently adopted a water quality ordinance that requires
that permanent structural water quality controls for regulated
activities over the Edwards Aquifer recharge zone must remove 85
percent of total suspended solids for the entire project. This
increases the amount of total suspended solids that must be removed
from projects within the City of Georgetown and its ETJ by 5 percent
over the existing requirements (i.e., removal of 80 percent total
suspended solids) found in the Edwards Aquifer Rules. In addition, the
ordinance requires that all regulated activities implement temporary
best management practices (BMPs) to minimize sediment runoff during
construction. Finally, the Adaptive Management Working Group is charged
specifically with reviewing Georgetown salamander monitoring data and
new research over time and recommending improvements to the City of
Georgetown's water quality ordinance that may be necessary to ensure
that it achieves its stated purposes. This Adaptive Management Working
Group, which includes representatives of the Service and TPWD, will
also review and make recommendations on the approval of any variances
to the ordinance.
In another example from a more closely related species, the COA
cited five declining Jollyville Plateau salamander populations from
1997 to 2006: Balcones District Park Spring, Tributary 3, Tributary 5,
Tributary 6, and Spicewood Tributary (O'Donnell et al. 2006, p. 4). All
of these populations occur within surface watersheds containing more
than 10 percent impervious cover (Service 2013, pp. 9-11). Springs with
relatively low amounts of impervious cover in their surface drainage
areas (6.77 and 0 percent for Franklin and Wheless Springs,
respectively) tend to have generally stable or increasing salamander
populations (Bendik 2011a, pp. 18-19). Bendik (2011a, pp. 26-27)
reported statistically significant declines in Jollyville Plateau
salamander populations over a 13-year period at six monitored sites
with high impervious cover (18 to 46 percent) compared to two sites
with low impervious cover (less than 1 percent). These results are
consistent with Bowles et al. (2006, p. 111), who found lower densities
of Jollyville Plateau salamanders at urbanized sites compared to non-
urbanized sites.
We recognize that the long-term survey data of Jollyville Plateau
salamanders using simple counts may not give conclusive evidence on the
long-term trend of the population at each site. However, based on the
threats and evidence from the literature and other information
available in our files (provided by peer reviewers of the Jollyville
Plateau salamander listing determination), the declines in counts seen
at urban Jollyville Plateau salamander sites are likely representative
of real declines in the population. Because of the similarities in
morphology, physiology, habitat requirements, and life history traits
shared with the Jollyville Plateau salamander, we expect downward
trends in Georgetown and Salado salamander populations in the future as
human population growth increases within the range of these species.
This human population growth is projected to increase by 377 percent in
the range of the Georgetown salamander and by 128 percent in the range
of the Salado salamander by 2050. As indicated by the analogies
presented above, subsequent urbanization within the watersheds occupied
by the Georgetown and Salado salamanders will likely cause declines in
habitat quality and numbers of individuals.
Impervious Cover Analysis
For this final rule, we calculated impervious cover within the
watersheds occupied by the Georgetown and Salado salamanders. In this
analysis, we delineated the surface areas that drain into spring sites
and which of these sites may be experiencing habitat quality
degradation as a result of impervious cover in the surface drainage
area. However, we only examined surface drainage areas for each spring
site for the Georgetown and Salado salamanders because we did not know
the recharge area for specific spring or cave sites. Also, we did not
account for riparian (stream edge) buffers or stormwater runoff control
measures, both of which have the potential to mitigate some of the
effects of impervious cover on streams (Schueler et al. 2009, pp. 312-
313). Please see the Service's refined impervious cover analysis
(Service 2013, pp. 2-7) for a description of the methods used to
conduct this analysis. This analysis may not represent the current
impervious cover because small areas may have gone undetected at the
resolution of our analysis and additional areas of impervious cover may
have been added since 2006, which is the year the impervious cover data
for our analysis were generated. We compared our results with the
results of similar analyses completed by SWCA, and impervious cover
percentages at individual sites from these analyses were generally
higher than our own (Service 2013, Appendix C).
Impervious Cover Categories
We examined studies that report ecological responses to watershed
impervious cover levels based on a variety of degradation measurements
(Service 2013, Table 1, p. 4). Most studies examined biological
responses to impervious cover (for example, aquatic invertebrate and
fish diversity), but several studies measured chemical and physical
responses as well (for example, water quality parameters and stream
channel modification). In light of these studies, we created the
following impervious cover categories:
None: 0 percent impervious cover in the watershed
Low: Greater than 0 percent to 10 percent impervious cover in
the watershed
Medium: Greater than 10 percent to 20 percent impervious cover
in the watershed
High: Greater than 20 percent impervious cover in the
watershed
Sites in the Low category may still be experiencing impacts from
urbanization, as cited in studies such as Coles et al. (2012, p. 64),
King et al. (2011, p. 1,664), and King and Baker (2010, p. 1,002). In
accordance with the findings of Bowles et al. (2006, pp. 113, 117-118),
sites in the Medium category are likely experiencing impacts from
urbanization that are negatively impacting salamander densities. Sites
in the High category are so degraded that habitat recovery will either
be impossible or very difficult (Schueler et al. 2009, pp. 310, 313).
Results of Our Impervious Cover Analysis
We estimated impervious cover percentages for each surface drainage
area of a spring known to have at least one population of either a
Georgetown or Salado salamander (cave locations were omitted). These
estimates and
[[Page 10263]]
maps of the surface drainage area of spring locations are provided in
our refined impervious cover analysis (Service 2013, pp. 1-25). Our
analysis did not include the watersheds for Hogg Hollow Spring, Hogg
Hollow II Spring, or Garey Ranch Spring because confirmation of the
Georgetown salamander at these sites was not received until after the
analysis was completed.
For the Georgetown salamander, a total of 12 watersheds were
delineated, representing 12 spring sites. The watersheds varied greatly
in size, ranging from the 1-ac (0.4-ha) watershed of Walnut Spring to
the 258,017-ac (104,416-ha) watershed of San Gabriel Spring. Most
watersheds (10 out of 12) were categorized as Low impervious cover. Two
watersheds had no impervious cover (Knight Spring and Walnut Spring)
and Swinbank Spring had the highest amount of impervious cover at 6.9
percent. The largest watershed, San Gabriel Spring, had a low
proportion of impervious cover overall. However, most of the impervious
cover in this watershed is in the area immediately surrounding the
spring site.
The Salado salamander had a total of six watersheds delineated,
representing seven different spring sites. The watersheds ranged in
size from the 67-ac (27-ha) watershed of Solana Spring to 86,681-ac
(35,079-ha) watershed of Big Boiling and Lil' Bubbly Springs. Five of
the six watersheds were categorized as Low, and the watershed of Hog
Hollow had no impervious cover. Although the largest watershed (Big
Boiling and Lil' Bubbly Springs) has a low amount of impervious cover
(0.41 percent), almost all of that impervious cover is located within
the Village of Salado surrounding the spring site.
Although most of the watersheds in our analysis were classified as
low, it is important to note that low levels of impervious cover (that
is, less than 10 percent) may degrade salamander habitat. Recent
studies in the eastern United States have reported large declines in
aquatic macroinvertebrates (the prey base of salamanders) at impervious
cover levels as low as 0.5 percent (King and Baker 2010, p. 1,002; King
et al. 2011, p. 1,664). Several authors have argued that negative
effects to stream ecosystems are seen at low levels of impervious cover
and gradually increase as impervious cover increases (Booth et al.
2002, p. 838; Groffman et al. 2006, pp. 5-6; Schueler et al. 2009, p.
313; Coles et al. 2012, pp. 4, 64).
Although general percentages of impervious cover within a watershed
are helpful in determining the general level of impervious cover within
watersheds, it does not tell the complete story of how urbanization may
be affecting salamanders or their habitat. Understanding how a
salamander might be affected by water quality degradation within its
habitat requires an examination of where the impervious cover occurs
and what other threat sources for water quality degradation are present
within the watershed (for example, non-point source runoff, highways
and other sources of hazardous materials, livestock and feral hogs, and
gravel and limestone mining (quarries); see discussions of these
sources in their respective sections in Factor A below). For example,
San Gabriel Spring's watershed (a Georgetown salamander site) has an
impervious cover of only 1.2 percent, but the salamander site is in the
middle of a highly urbanized area: the City of Georgetown. The habitat
is in poor condition, and Georgetown salamanders have not been observed
here since 1991 (Chippindale et al. 2000, p. 40; Pierce 2011b, pers.
comm.).
In addition, the spatial arrangement of impervious cover is
influential to the impacts that occur to aquatic ecosystems. Certain
urban pattern variables, such as land use intensity, land cover
composition, landscape configuration, and connectivity of the
impervious area are important in predicting effects to aquatic
ecosystems (Alberti et al. 2007, pp. 355-359). King et al. (2005, pp.
146-147) found that the closer developed land was to a stream in the
Chesapeake Bay watershed, the larger the effect it had on stream
macroinvertebrates. On a national scale, watersheds with development
clustered in one large area (versus being interspersed throughout the
watershed) and development located closer to streams had higher
frequency of high-flow events (Steuer et al. 2010, pp. 47-48, 52).
Based on these studies, it is likely that the way development is
situated in the landscape of a surface drainage area of a salamander
spring site plays a large role in how that development impacts
salamander habitat.
One major limitation of this analysis is that we only examined
surface drainage areas (watersheds) for each spring site for the
Georgetown and Salado salamanders. In addition to the surface habitat,
these salamanders use the subsurface habitat. Moreover, the base flow
of water discharging from the springs on the surface comes from
groundwater sources, which are in turn replenished by recharge features
on the surface. As Shade et al. (2008, p. 3-4) points out, ``. . .
little is known of how water recharges and flows through the subsurface
in the Northern Segment of the Edwards Aquifer. Groundwater flow in
karst is often not controlled by surface topography and crosses beneath
surface water drainage boundaries, so the sources and movements of
groundwater to springs and caves are poorly understood. Such
information is critical to evaluating the degree to which salamander
sites can be protected from urbanization.'' So a recharge area for a
spring may occur within the surface watershed, or it could occur many
miles away in a completely different watershed. A site completely
surrounded by development may still contain unexpectedly high water
quality because that spring's base flow is coming from a distant
recharge area that is free from impervious cover. While some dye tracer
work has been done in the Northern Segment (Shade et al. 2008, p. 4),
clearly delineated recharge areas that flow to specific springs in the
Northern Segment have not been identified for any of these spring
sites; therefore, we could not examine impervious cover levels on
recharge areas to better understand how development in those areas may
impact salamander habitat.
Impervious cover within the watersheds of the Georgetown and Salado
salamanders alone (that is, without the consideration of additional
threat sources that may be present at specific sites) could cause
irreversible declines or extirpation of populations with continuous
exposure to water quality degradation over a relatively short time span
without measures in place to reduce these threats. Although the
impervious cover levels for the Georgetown and Salado salamanders
remain relatively low at the present time, we expect impacts from this
threat to increase in the future as urbanization expands within the
surface watersheds for these species as well. This has already been
observed in the closely related Jollyville Plateau salamander. Bowles
et al. (2006, pp. 113, 117-118) found lower Jollyville Plateau
salamander densities in watersheds with more than 10 percent impervious
cover. Given the similar morphology, physiology, habitat requirements,
and life-history traits between the Jollyville Plateau, Georgetown, and
Salado salamanders, we expect that downward trends in Georgetown and
Salado salamander populations will occur as human population growth
increases. As previously noted, the human population is projected to
increase by 377 percent in the range of the Georgetown
[[Page 10264]]
salamander and by 128 percent in the range of the Salado salamander by
2050. Subsequent urbanization will likely cause declines in habitat
quality and numbers of individuals at sites occupied by these species.
The recently adopted ordinances in the City of Georgetown may reduce
these threats. The Adaptive Management Working Group will provide the
monitoring and research to track whether the ordinance is helping to
reduce this threat.
Hazardous Material Spills
The Edwards Aquifer is at risk from a variety of sources of
contaminants and pollutants (Ross 2011, p. 4), including hazardous
materials that have the potential to be spilled or leaked, resulting in
contamination of both surface and groundwater resources (Service 2005,
pp. 1.6-14-1.6-15). Utility structures such as storage tanks or
pipelines (particularly gas and sewer lines) can accidentally
discharge. Any activity that involves the extraction, storage,
manufacture, or transport of potentially hazardous substances, such as
fuels or chemicals, can contaminate water resources and cause harm to
aquatic life. Spill events can involve a short release with immediate
impacts, such as a collision that involves a tanker truck carrying
gasoline. Alternatively, the release can be long-term, involving the
slow release of chemicals over time, such as a leaking underground
storage tank.
A peer reviewer for the proposed rule provided information from the
National Response Center's database of incidents of chemical and
hazardous materials spills (http://www.nrc.uscg.mil/foia.html) from
anthropogenic activities including, but not limited to, automobile or
freight traffic accidents, intentional dumping, storage tanks, and
industrial facilities. The number of incidents is likely to be an
underestimate of the total number of incidents because not all
incidents are discovered or reported. The database produced 189 records
of spill events (33 that directly affected a body of water) in
Williamson County between 1990 and 2012. Our search of the database
produced 49 records of spill events that all directly affected water in
Bell County between 1990 and 2013. Spills that did not directly affect
aquatic environments may have indirectly done so by contaminating soils
within watersheds that recharge springs where salamanders are known to
occur (Gillespie 2012, University of Texas, pers. comm.). The risk of
this type of contamination is currently ongoing and expected to
increase as urbanization continues within the ranges of the Georgetown
and Salado salamanders.
Hazardous material spills pose a significant threat to the
Georgetown and Salado salamanders, and impacts from spills could
increase substantially under drought conditions due to lower dilution
and buffering capability of impacted water bodies. Spills under low-
flow conditions are predicted to have an impact at much smaller volumes
(Turner and O'Donnell 2004, p. 26). A significant hazardous materials
spill within stream drainages of the Georgetown or Salado salamander
could have the potential to threaten its long-term survival and
sustainability of multiple populations or possibly the entire species.
For example, a single hazardous materials spill on Interstate Highway
35 in the Village of Salado could cause three (Big Boiling Springs,
Lil' Bubbly Springs, and Lazy Days Fish Farm Springs) of the seven
known Salado salamander populations to go extinct. The City of
Georgetown ordinances have a requirement that new roadways providing a
capacity of 25,000 vehicles per day must provide for hazardous spill
containment. This measure reduces the threat of spills on larger
roadways in the future. In combination with the other threats
identified in this final rule, a catastrophic hazardous materials spill
could contribute to the species' risk of extinction by reducing its
overall probability of persistence. Furthermore, we consider hazardous
material spills to be an ongoing significant threat to the Georgetown
and Salado salamanders due to their limited distributions, the
abundance of potential sources, and the number of salamanders that
could be killed during a single spill event.
Underground Storage Tanks
The risk of hazardous material spills from underground storage
tanks is widespread in Texas and is expected to increase as
urbanization continues to occur. As of 1996, more than 6,000 leaking
underground storage tanks in Texas had resulted in contaminated
groundwater (Mace et al. 1997, p. 2), including a large leak in the
range of the Georgetown salamander (Mace et al. 1997, p. 32). In 1993,
approximately 6,000 gallons (22,712 liters) of gasoline leaked from an
underground storage tank located near Krienke Springs in southern
Williamson County, Texas, which is known to be occupied by the
Jollyville Plateau salamander (Manning 1994, p. 1). The leak originated
from an underground storage tank from a gas station near the salamander
site. This incident illustrates that despite laws or ordinances that
require all underground storage tanks to be protected against
corrosion, installed properly, and equipped with spill protection and
leak detection mechanisms, leaks can still occur in urbanized areas
despite the precautions put in place to prevent them (Manning 1994, p.
5). As human population growth increases within the ranges of the
Georgetown and Salado salamanders, such leaks could be threat to these
species.
Several groundwater contamination incidents have occurred within
Salado salamander habitat (Price et al. 1999, p. 10). Big Boiling
Springs is located on the south bank of Salado Creek, near locations of
past contamination events (Chippindale et al. 2000, p. 43). Between
1989 and 1993, at least four incidents occurred within 0.25 mi (0.4 km)
from the spring site, including a 700-gallon (2,650-liter) and 400-
gallon (1,514-liter) gasoline spill and petroleum leaks from two
underground storage tanks associated with a gas station and a gas
distributor business, respectively (Price et al. 1999, p. 10). Because
no follow-up studies were conducted, we have no information to indicate
what effect these spills had on the species or its habitat. However,
between 1991 and 1998, only a single salamander was observed at Big
Boiling Springs despite multiple surveys (Chippindale et al. 2000, p.
43; TPWD 2011, p. 2). Between 2008 and 2010, one salamander was
confirmed by biologists (Gluesenkamp 2010, TPWD, pers. comm.) at Lil'
Bubbly Spring, and one additional unconfirmed sighting of a Salado
salamander in Big Boiling Springs was reported by a citizen of Salado,
Texas.
The threat of water quality degradation from an underground storage
tank alone (that is, without the consideration of additional threat
sources that may be present at specific sites) could cause irreversible
declines or extirpation in local populations or significant declines in
habitat quality of the Georgetown or Salado salamander with only one
exposure event. This is considered to be an ongoing threat of high
impact to the Georgetown and Salado salamanders. We expect this to
become a more significant threat in the future for these salamander
species as urbanization continues to expand within their surface
watersheds.
Highways
The transport of hazardous materials is common on many highways,
which are major transportation routes (Thompson et al. 2011, p. 1).
Every year, thousands of tons of hazardous materials are transported
over Texas highways (Thompson et al. 2011, p. 1).
[[Page 10265]]
Transporters of hazardous materials (such as gasoline, cyclic
hydrocarbons, fuel oils, and pesticides) carry volumes ranging from a
few gallons up to 10,000 gallons (37,854 liters) or more of hazardous
material (Thompson et al. 2011, p. 1). An accident involving hazardous
materials can cause the release of a substantial volume of material
over a very short period of time. As such, the capability of standard
stormwater management structures (or best management practices) to trap
and treat such releases might be overwhelmed (Thompson et al. 2011, p.
2).
Interstate Highway 35 crosses the watersheds that contribute
groundwater to spring sites known to be occupied by the Georgetown and
Salado salamanders. A catastrophic spill could occur if a transport
truck overturned and its contents entered the recharge zone of the
Northern Segment of the Edwards Aquifer. Researchers at Texas Tech
University reviewed spill records to identify locations or segments of
highway where spill incidents on Texas roadways are more numerous and,
therefore, more likely to occur than other areas of Texas. These
researchers found that one such area is a 10-mi (16-km) radius along
Interstate Highway 35 within Williamson County (Thompson et al. 2011,
pp. 25, 44). Three of the five spills reported in this area between
2000 and 2006 occurred on this highway within the City of Georgetown,
and one occurred on the same highway within the City of Round Rock
(Thompson et al. 2011, pp. 25-26, 44). As recently as 2011, a fuel
tanker overturned in Georgetown and spilled 3,500 gallons (13,249
liters) of gasoline (McHenry et al. 2011, p. 1). A large plume of
hydrocarbons was detected within the Edwards Aquifer underneath
Georgetown in 1997 (Mace et al. 1997, p. 32), possibly the result of a
leaking fuel storage tank. Thus, spills from Interstate Highway 35 are
an ongoing threat source. The City of Georgetown's water quality
ordinance now requires that new roadways or expansions to existing
roadways that provide a capacity of 25,000 vehicles per day and are
located on the Edwards Aquifer recharge zone must provide for spill
containment as described in TCEQ's Optional Enhanced Measures. This
measure will reduce the threat of hazardous spills on new roadways or
expansions but does not address the threat from existing roadways.
Transportation accidents involving hazardous materials spills at
bridge crossings are of particular concern because recharge areas in
creek beds can transport contaminants directly into the aquifer
(Service 2005, p. 1.6-14). Salado salamander sites located downstream
of Interstate Highway 35 may be particularly vulnerable due to their
proximity to this major transportation corridor. Interstate Highway 35
crosses Salado Creek just 760 to 1,100 ft (231 to 335 m) upstream from
three spring sites (Big Boiling Springs, Lil' Bubbly Springs, and Lazy
Days Fish Farm Springs) where the Salado salamander is known to occur.
The highway also crosses the surface watershed of an additional Salado
salamander site, Robertson Spring. Should a hazardous materials spill
occur at the Interstate Highway 35 bridge that crosses at Salado Creek
or over the watershed of Robertson Spring, the Salado salamander could
be at risk from contaminants entering the water flowing into its
surface habitat downstream.
In addition, the Texas Department of Transportation is
reconstructing a section of Interstate Highway 35 within the Village of
Salado (Najvar 2009, Service, pers. comm.). This work includes the
replacement of four bridges that cross Salado Creek (two main lane
bridges and two frontage road bridges) in an effort to widen the
highway at this location. This project could affect the risk of
hazardous materials spills and runoff into Salado Creek upstream of
known Salado salamander locations. In August 2009, the Texas Department
of Transportation began working with the Service to identify measures,
such as the installation of permanent water quality control mechanisms
to contain runoff, to protect the Salado salamander and its habitat
from the effects of this project (Najvar 2009, Service, pers. comm.).
The threat of water quality degradation from highways alone (that
is, without the consideration of additional threat sources that may be
present at specific sites) could cause irreversible declines or
extirpation in local populations or significant declines in habitat
quality of any of the four central Texas salamander species with only
one exposure event. We consider this to be an ongoing threat of high
impact to the Georgetown and Salado salamanders. Given the amount of
urbanization predicted for Williamson and Bell Counties, Texas, the
risk of exposure from this threat is expected to increase in the future
as well.
Water and Sewage Lines
Sewage spills often include contaminants such as nutrients,
polycyclic aromatic hydrocarbons (PAHs), metals, pesticides,
pharmaceuticals, and high levels of fecal coliform bacteria (Turner and
O'Donnell 2004, p. 27). Increased ammonia levels and reduced dissolved
oxygen are the most likely impacts of a sewage spill that could cause
rapid mortality of large numbers of salamanders (Turner and O'Donnell
2004, p. 27). Fecal coliform bacteria from sewage spills cause diseases
in salamanders and their prey base (Turner and O'Donnell 2004, p. 27).
Municipal water lines that convey treated drinking water throughout the
surrounding areas of Georgetown and Salado salamander habitat could
break and potentially flow into surface or subsurface habitat, exposing
salamanders to chlorine concentrations that are potentially toxic. A
typical chlorine concentration in a water line is 1.5 mg/L, and a
lethal concentration of chloride for the related San Marcos salamander
is 0.088 mg/L (Herrington and Turner 2009, p. 1).
The Georgetown salamander is particularly exposed to the threat of
water and sewage lines. As of the date of this rule, there are eight
water treatment plants within the Georgetown city limits, with
wastewater and chlorinated drinking water lines running throughout
Georgetown salamander stream drainages (City of Georgetown 2008, p.
3.37). A massive wastewater line is being constructed in the South San
Gabriel River drainage (City of Georgetown 2008, p. 3.22), which is
within the watershed of one known Georgetown salamander site. Almost
700 septic systems were permitted or inspected in Georgetown in 2006
(City of Georgetown 2008, p. 3.36). Service staff also noted a sewage
line that runs nearby Bat Well Cave. Data submitted to the Service
during our comment period (SWCA 2012, p. 20) indicated that one
Georgetown salamander site (Cedar Breaks Spring) had a concentration of
fecal coliform bacteria [83,600 colony-forming units per 100
milliliters (cfu/100mL)] 418 times the concentration that the Service
recommended to be protective of federally listed salamanders (200 cfu/
100mL) (White et al. 2006, p. 51). It is unknown if this elevated
concentration of fecal coliform bacteria was the result of a sewage or
septic spill, or what impact this poor water quality had on the Cedar
Breaks Spring population.
Spills from sewage and water lines have been documented in the past
in the central Texas area within the ranges of closely related
salamander species. There are 9,470 known septic facilities in the
Barton Springs Segment of the Edwards Aquifer as of 2010 (Herrington et
al. 2010, p. 5), up from 4,806 septic systems in 1995 (COA 1995, p. 3-
13). In one COA survey of these septic systems, over 7 percent were
identified as failing (no longer functioning properly, causing
[[Page 10266]]
water from the septic tank to leak out and accumulate on the ground
surface) (COA 1995, p. 3-18). Sewage spills from pipelines also have
been documented in watersheds supporting Jollyville Plateau salamander
populations (COA 2001, pp. 16, 21, 74). For example, in 2007, a sewage
line overflowed an estimated 50,000 gallons (190,000 liters) of raw
sewage into the Stillhouse Hollow drainage area of Bull Creek below the
area where salamanders are known to occur (COA 2007b, pp. 1-3). The
human population is projected to increase by 377 percent in the range
of the Georgetown salamander and by 128 percent in the range of the
Salado salamander by 2050. We expect that subsequent urbanization will
increase the prevalence of water and sewage systems within the areas
where Georgetown and Salado salamander populations are known to occur,
and thereby increase the exposure of salamanders to this threat source.
The threat of water quality degradation from water and sewage lines
alone (that is, without the consideration of additional threat sources
that may be present at specific sites) could cause irreversible
declines or extirpation in local populations or significant declines in
habitat quality with only one exposure event. We consider this to be an
ongoing threat of high impact to the Georgetown salamander that is
likely to increase in the future as urbanization expands within the
ranges of these species. Although we are unaware of any information
that indicates water and sewage lines are located in areas that could
impact Salado salamanders if spills occurred, we expect this to become
a significant threat in the future for this species as urbanization
continues to expand within its surface watersheds.
Construction Activities
Short-term increases in pollutants, particularly sediments, can
occur during construction in areas of new development. When vegetation
is removed and rain falls on unprotected soils, large discharges of
suspended sediments can erode from newly exposed areas, resulting in
increased sedimentation in downstream drainage channels (Schueler 1987,
pp. 1-4; Turner 2003, p. 24; O'Donnell et al. 2005, p. 15). This
increased sedimentation from construction activities has been linked to
declines in Jollyville Plateau salamander counts at multiple sites
(Turner 2003, p. 24; O'Donnell et al. 2006, p. 34).
Cave sites are also impacted by construction, as Testudo Tube Cave
(Jollyville Plateau salamander habitat) showed an increase in nickel,
calcium, and nitrates/nitrites after nearby road construction (Richter
2009, pp. 6-7). Barton Springs (Austin blind salamander habitat) is
also under the threat of pollutant loading due to its proximity to
construction activities and the spring's location at the downstream
side of the watershed (COA 1997, p. 237). The COA (1995, pp. 3-11)
estimated that construction-related sediment and in-channel erosion
accounted for approximately 80 percent of the average annual sediment
load in the Barton Springs watershed. In addition, the COA (1995, pp.
3-10) estimated that total suspended sediment loads have increased 270
percent over pre-development loadings within the Barton Springs Segment
of the Edwards Aquifer. Because the Jollyville Plateau and Barton
Springs salamanders are similar to the Georgetown and Salado salamander
with regard to size, morphology, physiology, life history traits and
habitat requirements, we expect similar declines to occur for the
Georgetown and Salado salamanders from construction activities as the
human population growth increases and subsequent development follows
within surface watersheds of these species.
At this time, we are not aware of any studies that have examined
sediment loading due to construction activities within the watersheds
of Georgetown or Salado salamander habitats. However, because
construction occurs and is expected to continue in many of these
watersheds occupied by the Georgetown and Salado salamanders as the
human population is projected to increase by 377 percent in the range
of the Georgetown salamander and by 128 percent in the range of the
Salado salamander by 2050, we have determined that the threat of
construction in areas of new development applies to these species as
well. The City of Georgetown's water quality ordinance now requires
stream buffers for all streams in the Edwards Aquifer recharge zone
within the City of Georgetown and its ETJ that drain more than 64 acres
(26 ha). These buffers are similar to those required under similar
water quality regulations in central Texas and will help reduce the
amount of sediment and other pollutants that enter waterways.
The ordinance also requires that permanent structural water quality
controls for regulated activities over the Edwards Aquifer recharge
zone must remove 85 percent of total suspended solids for the entire
project. This increases the amount of total suspended solids that must
be removed from projects within the City of Georgetown and its ETJ by 5
percent over the existing requirements (i.e., removal of 80 percent
total suspended solids) found in the Edwards Aquifer Rules. Lastly, the
ordinance requires that all developments implement temporary BMPs to
minimize sediment runoff during construction. Construction is
intermittent and temporary, but it affects both surface and subsurface
habitats and is occurring throughout the ranges of these salamanders.
Therefore, we have determined that this threat is ongoing and will
continue to affect the Georgetown and Salado salamanders and their
habitats in the future.
Also, the physical construction of pipelines, shafts, wells, and
similar structures that penetrate the subsurface has the potential to
negatively affect subsurface habitat for salamander species. It is
known that the Georgetown and Salado salamanders inhabit the subsurface
environment and that water flows through the subsurface to the surface
habitat. Tunneling for underground pipelines can destroy potential
habitat by removing subsurface material, thereby destroying subsurface
spaces/conduits in which salamanders can live, grow, forage, and
reproduce. Additional material can become dislodged and result in
increased sediment loading into the aquifer and associated spring
systems. In addition, disruption of water flow to springs inhabited by
salamanders can occur through the construction of tunnels and vertical
shafts to access them. Because of the complexity of the aquifer and
subsurface structure and because detailed maps of the underground
conduits that feed springs in the Edwards Aquifer are not available,
tunnels and shafts have the possibility of intercepting and severing
those conduits (COA 2010a, p. 28). Affected springs could rapidly
become dry and would not support salamander populations. The closer a
shaft or tunnel location is to a spring, the more likely that the
construction will impact a spring (COA 2010a, p. 28). Even small shafts
pose a threat to nearby spring systems. As the human population is
projected to increase by 377 percent in the range of the Georgetown
salamander and by 128 percent in the range of the Salado salamander by
2050, we expect subsurface construction of pipelines, shafts, wells,
and similar structures to be a threat to their surface and subsurface
habitats. However, under the City of Georgetown's water quality
ordinance, these types of activities will no longer be permitted within
262 ft (80
[[Page 10267]]
m) of occupied Georgetown salamander sites.
The threat of water quality degradation from construction
activities alone (that is, without the consideration of additional
threat sources that may be present at specific sites) could cause
irreversible declines or extirpation in local populations or
significant declines in habitat quality of the salamander species with
only one exposure event (if subsurface flows were interrupted or
severed) or with repeated exposure over a relatively short time span.
From information available in our files and provided to us during the
peer review and public comment period for the proposed rule, we found
that 3 of the 17 Georgetown salamander sites have been known to have
had construction activities around their perimeters, and 1 has been
modified within the spring site itself. Construction activities have
led to physical habitat modification in at least three of the seven
known Salado salamander spring sites. Even though the impacts of water
quality degradation from construction activities is reduced by the City
of Georgetown's water quality ordinance, we consider future
construction activities to be an ongoing threat of high impact to both
the Georgetown and Salado salamanders that are likely to increase as
urbanization expands within their respective surface watersheds.
Quarries
Construction activities within rock quarries can permanently alter
the geology and groundwater hydrology of the immediate area, and
adversely affect springs that are hydrologically connected to impacted
sites (Ekmekci 1990, p. 4; van Beynan and Townsend 2005, p. 104;
Humphreys 2011, p. 295). Limestone rock is an important raw material
that is mined in quarries all over the world due to its popularity as a
building material and its use in the manufacture of cement (Vermeulen
and Whitten 1999, p. 1). The potential environmental impacts of
quarries include destruction of springs or collapse of karst caverns,
as well as impacts to water quality through siltation and
sedimentation, and impacts to water quantity through water diversion,
dewatering, and reduced flows (Ekmekci 1990, p. 4; van Beynan and
Townsend 2005, p. 104). The mobilization of fine materials from
quarries can lead to the occlusion of voids and the smothering of
surface habitats for aquatic species downstream (Humphreys 2011, p.
295).
Quarry activities can also generate pollution in the aquatic
ecosystem through leaks or spills of waste materials from mining
operations (such as petroleum products) (Humphreys 2011, p. 295). For
example, a spill of almost 3,000 gallons (11,356 liters) of diesel from
an above-ground storage tank occurred on a limestone quarry in New
Braunfels, Texas (about 4.5 mi (7.2 km) from Comal Springs in the
Southern Segment of the Edwards Aquifer) in 2000 (Ross et al. 2005, p.
14). Also, perchlorate (a chemical used in producing explosives used in
quarries) contamination was detected in the City of Georgetown public
water supply wells in November 2003. A total of 46 private and public
water wells were sampled in December 2004 in Williamson County (Berehe
2005, p. 44). Out of these, five private wells had detections of
perchlorate above the TCEQ interim action levels of 4.0 parts per
billion (ppb). Four surface water (spring) samples had detection
ranging from 6.3 to 9.2 ppb (Berehe 2005, p. 44). Perchlorate is known
to affect thyroid functions, which are responsible for helping to
regulate embryonic growth and development in vertebrate species (Smith
et al. 2001, p. 306). Aquatic organisms inhabiting perchlorate-
contaminated surface water bodies contain detectable concentrations of
perchlorate (Smith et al. 2001, pp. 311-312). Perchlorate has been
shown to cause malformations in embryos, delay larval growth and
development, and decrease reproductive success in laboratory studies in
the African clawed frog (Xenopus laevis) (Dumont 2008, pp. 5, 8, 12,
19). Because the thyroid has the same function in salamander physiology
as it does for the African clawed frog, we expect perchlorate to affect
the Georgetown and Salado salamanders in a similar manner.
Limestone is a common geologic feature of the Edwards Aquifer, and
active quarries exist throughout the region. For example, at least 3 of
the 17 Georgetown salamander sites (Avant Spring, Knight [Crockett
Gardens] Spring, and Cedar Breaks Hiking Trail Spring) occur adjacent
to a limestone quarry that has been active since at least 1995. Avant
Spring is within 328 ft (100 m) and Knight and Cedar Breaks Hiking
Trail Springs are each between 1,640 and 2,624 ft (500 and 800 m) from
the quarry. The population status of the Georgetown salamander is
unknown at Knight Spring and Cedar Breaks Hiking Trail Spring, but
salamanders are seen infrequently and in low abundance at the closest
spring to the quarry (Avant Spring; Pierce 2011c, Southwestern
University, pers. comm.). In total, there are currently quarries
located in the watersheds of 5 of the 12 Georgetown salamander surface
sites and 5 of the 7 Salado salamander sites. Therefore, we consider
this to be an ongoing threat of high impact given the exposure risk of
this threat to the Georgetown and Salado salamanders that could worsen
as quarries expand in the future.
Contaminants and Pollutants
Contaminants and pollutants are stressors that can affect
individual salamanders or their habitats or their prey. They find their
way into aquatic habitat through a variety of ways, including
stormwater runoff, point (a single identifiable source) and non-point
(coming from many diffuse sources) discharges, and hazardous material
spills (Coles et al. 2012, p. 21). For example, sediments eroded from
soil surfaces as a result of stormwater runoff can concentrate and
transport contaminants (Mahler and Lynch 1999, p. 165). The Georgetown
and Salado salamanders and their prey species are directly exposed to
sediment-borne contaminants present within the aquifer and discharging
through the spring outlets. For example, in addition to sediment, trace
metals such as arsenic, cadmium, copper, lead, nickel, and zinc were
found in Barton Springs in the early 1990s (COA 1997, pp. 229, 231-
232). Such contaminants associated with sediments are known to
negatively affect survival and growth of an amphipod species, which are
part of the prey base of the Georgetown and Salado salamanders
(Ingersoll et al. 1996, pp. 607-608; Coles et al. 2012, p. 50). In
addition, various industrial and municipal activities result in the
discharge of treated wastewater or unintentional release of industrial
contaminants as point source pollution. Urban environments are host to
a variety of human activities that generate many types of sources for
contaminants and pollutants. These substances, especially when
combined, often degrade nearby waterways and aquatic resources within
the watershed (Coles et al. 2012, pp. 44-53).
As a karst aquifer system, the Edwards Aquifer is more vulnerable
to the effects of contamination due to: (1) A large number of conduits
that offer no filtering capacity, (2) high groundwater flow velocities,
and (3) the relatively short amount of time that water is inside the
aquifer system (Ford and Williams 1989, pp. 518-519). These
characteristics of the aquifer allow contaminants in the watershed to
enter and move through the aquifer more easily, thus reaching
salamander habitat within spring sites more quickly than other types of
aquifer systems.
[[Page 10268]]
Amphibians, especially their eggs and larvae (which are usually
restricted to a small area within an aquatic environment), are
sensitive to many different aquatic pollutants (Harfenist et al. 1989,
pp. 4-57). Contaminants found in aquatic environments, even at
sublethal concentrations, may interfere with a salamander's ability to
develop, grow, or reproduce (Burton and Ingersoll 1994, pp. 120, 125).
Salamanders in the central Texas region are particularly vulnerable to
contaminants, because they have evolved under very stable environmental
conditions, remain aquatic throughout their entire life cycle, have
highly permeable skin, have severely restricted ranges, and cannot
escape contaminants in their environment (Turner and O'Donnell 2004, p.
5). In addition, macroinvertebrates, such as small freshwater
crustaceans (amphipods and copepods), that aquatic salamanders feed on
are especially sensitive to water pollution (Phipps et al. 1995, p.
282; Miller et al. 2007, p. 74; Coles et al. 2012, pp. 64-65). For
example, studies in the Bull Creek watershed in Austin, Texas, found a
loss of some sensitive macroinvertebrate species, potentially due to
contaminants of nutrient enrichment and sediment accumulation (COA
2001, p. 15; COA 2010b, p. 16). Below, we discuss specific contaminants
and pollutants that may be impacting the Georgetown and Salado
salamanders.
Polycyclic Aromatic Hydrocarbons
Polycyclic aromatic hydrocarbons (PAHs) are a common form of
aquatic contaminants in urbanized areas that could affect salamanders,
their habitat, or their prey. This form of pollution can originate from
petroleum products, such as oil or grease, or from atmospheric
deposition as a byproduct of combustion (for example, vehicular
combustion). These pollutants accumulate over time on impervious cover,
contaminating water supplies through urban and highway runoff (Van
Metre et al. 2000, p. 4,067; Albers 2003, pp. 345-346). Although
information is lacking on PAH loading in Williamson and Bell Counties,
research shows that the main source of PAH loading in Austin-area
streams is parking lots with coal tar emulsion sealant, even though
this type of lot only covers 1 to 2 percent of the watersheds (Mahler
et al. 2005, p. 5,565). A recent analysis of the rate of wear on coal
tar lots revealed that the sealcoat wears off relatively quickly and
contributes more to PAH loading than previously thought (Scoggins et
al. 2009, p. 4,914).
Petroleum and petroleum byproducts can adversely affect living
organisms by causing direct toxic action, altering water chemistry,
reducing light, and decreasing food availability (Albers 2003, p. 349).
Exposure to PAHs at certain levels can cause impaired reproduction,
reduced growth and development, and tumors or cancer in species of
amphibians, reptiles, and other organisms (Albers 2003, p. 354). Coal
tar pavement sealant slowed hatching, growth, and development of a frog
(Xenopus laevis) in a laboratory setting (Bryer et al. 2006, pp. 244-
245). High concentrations of PAHs from coal tar sealant negatively
affected the righting ability (amount of time needed to flip over after
being placed on back) of adult eastern newts (Notophthalmus
viridescens) and may have also damaged the newt's liver (Sparling et
al. 2009, pp. 18-20). For juvenile spotted salamanders (Ambystoma
maculatum), PAHs reduced growth in the lab (Sparling et al. 2009, p.
28). Bommarito et al. (2010, pp. 1,151-1,152) found that spotted
salamanders displayed slower growth rates and diminished swimming
ability when exposed to PAHs. These contaminants are also known to
cause death, reduced survival, altered physiological function,
inhibited reproduction, and changes in community composition of
freshwater invertebrates (Albers 2003, p. 352). From the information
available above, we conclude that PAHs are known to cause disruptions
to the survival, growth, development, and reproduction in a variety of
amphibian species and alterations to their prey base of aquatic
invertebrates. Therefore, the same effects are expected to occur to the
Georgetown and Salado salamanders when exposed to PAHs.
This form of aquatic contaminant has already been documented in the
central Texas area within the urbanized ranges of closely related
salamander species. Limited sampling by the COA has detected PAHs at
concentrations of concern at multiple sites within the range of the
Jollyville Plateau salamander. Most notable were the levels of nine
different PAH compounds at the Spicewood Springs site in the Shoal
Creek drainage area, which were above concentrations known to adversely
affect aquatic organisms (O'Donnell et al. 2005, pp. 16-17). The
Spicewood Springs site is located within an area with greater than 30
percent impervious cover and down gradient from a commercial business
that changes vehicle oil. This is also one of the sites where
salamanders have shown declines in abundance (from an average of 12
individuals per visit in 1997 to an average of 2 individuals in 2005)
during the COA's long-term monitoring studies (O'Donnell et al. 2006,
p. 47). Another study found several PAH compounds in seven Austin-area
streams, including Barton, Bull, and Walnut Creeks, downstream of coal
tar sealant parking lots (Scoggins et al. 2007, p. 697). Sites with
high concentrations of PAHs (located in Barton and Walnut Creeks) had
fewer macroinvertebrate species and lower macroinvertebrate density
(Scoggins et al. 2007, p. 700). This form of contamination has also
been detected at Barton Springs, which is the Austin blind salamander's
habitat (COA 1997, p. 10).
The threat of water quality degradation from PAH exposure alone
(that is, without the consideration of additional threat sources that
may be present at specific sites) could cause irreversible declines or
extirpation in local populations or significant declines in habitat
quality of any of the Georgetown and Salado salamander sites with
continuous or repeated exposure. In some instances, exposure to PAH
contamination could negatively impact a salamander population in
combination with exposure to other sources of water quality
degradation, resulting in significant habitat declines or other
significant negative impacts (such as loss of invertebrate prey
species). We consider water quality degradation from PAH contamination
to be a threat of high impact to Georgetown and Salado salamanders now
and in the future as urbanization increases within these species'
surface watersheds.
Pesticides
Pesticides (including herbicides and insecticides) are also
associated with urban areas. Sources of pesticides include lawns, road
rights-of-way, and managed turf areas, such as golf courses, parks, and
ball fields. Pesticide application is also common in residential,
recreational, and agricultural areas. Pesticides have the potential to
leach into groundwater through the soil or be washed into streams by
stormwater runoff. Pesticides are known to impact amphibian species in
a number of ways. For example, Reylea (2009, p. 370) demonstrated that
diazinon reduces growth and development in larval amphibians. Another
pesticide, carbaryl, causes mortality and deformities in larval
streamside salamanders (Ambystoma barbouri) (Rohr et al. 2003, p.
2,391). The Environmental Protection Agency (EPA) (2007, p. 9) also
found that carbaryl is likely to adversely affect the
[[Page 10269]]
Barton Springs salamander both directly and indirectly through
reduction of prey. Additionally, atrazine has been shown to impair
sexual development in male amphibians (African clawed frogs) at
concentrations as low as 0.1 parts per billion (Hayes 2002, p. 5,477).
Atrazine levels were found to be greater than 0.44 parts per billion
after rainfall in Barton Springs Pool (Mahler and Van Mere 2000, pp. 4,
12). From the information available above, we conclude that pesticides
are known to cause disruptions to the survival, growth, development,
and reproduction in a variety of amphibian species. Therefore, we
conclude such effects may occur to the Georgetown and Salado
salamanders when exposed to pesticides as well.
We acknowledge that in 2007 a Scientific Advisory Panel (SAP) of
the EPA reviewed the available information on atrazine effects on
amphibians and concluded that atrazine concentrations less than 100
[micro]g/L had no effects on clawed frogs. However, the 2012 SAP is
currently re-examining the conclusions of the 2007 SAP using a meta-
analysis of published studies along with additional studies on more
species (EPA 2012, p. 35). The 2012 SAP expressed concern that some
studies were discounted in the 2007 SAP analysis, including studies
like Hayes (2002, p. 5,477) that indicated that atrazine is linked to
endocrine (hormone) disruption in amphibians (EPA 2012, p. 35). In
addition, the 2007 SAP noted that their results on clawed frogs are
insufficient to make global conclusions about the effects of atrazine
on all amphibian species (EPA 2012, p. 33). Accordingly, the 2012 SAP
has recommended further testing on at least three amphibian species
before a conclusion can be reached that atrazine has no effect on
amphibians at concentrations less than 100 [micro]g/L (EPA 2012, p.
33). Due to potential differences in species sensitivity, exposure
scenarios that may include dozens of chemical stressors simultaneously,
and multigenerational effects that are not fully understood, we
continue to view pesticides, including carbaryl, atrazine, and many
others to which aquatic organisms may be exposed, as a potential threat
to water quality, salamander health, and the health of aquatic
organisms that comprise the diet of salamanders.
The threat of water quality degradation from pesticide exposure
alone (that is, without the consideration of additional threat sources
that may be present at specific sites) could cause irreversible
declines or extirpation in local populations or significant declines in
habitat quality of the Georgetown and Salado salamanders. In some
instances, exposure to pesticide contamination could negatively impact
a salamander population in combination with exposure to other sources
of water quality degradation, resulting in significant habitat declines
or other significant negative impacts (such as loss of invertebrate
prey species). Although the best available information does not
indicate that pesticides have been detected in the aquatic environments
within the ranges of the Georgetown and Salado salamanders to date
(SWCA 2012, pp. 17-18), we expect this to become a significant threat
in the future for these species as the human population expands within
their surface watersheds.
Nutrients
Nutrient input (such as phosphorus and nitrogen) to watershed
drainages, which often results in abnormally high organic growth in
aquatic ecosystems, can originate from multiple sources, such as human
and animal wastes, industrial pollutants, and fertilizers (from lawns,
golf courses, or croplands) (Garner and Mahler 2007, p. 29). As the
human population grows and subsequent urbanization occurs within the
ranges of the Georgetown and Salado salamanders, they will likely
become more susceptible to the effects of excessive nutrients within
their habitats because their exposure increases. To illustrate, an
estimated 102,262 domestic dogs and cats (pet waste is a potential
source of excessive nutrients) were known to occur within the Barton
Springs Segment of the Edwards Aquifer in 2010 (Herrington et al. 2010,
p. 15). Their distributions were correlated with human population
density (Herrington et al. 2010, p. 15).
Human population growth will bring about an increase in the use of
nutrients that are harmful to aquatic species, such as the Georgetown
and Salado salamanders. This was the case as urban development
increased within the Jollyville Plateau salamander's range. Various
residential properties and golf courses use fertilizers to maintain
turf grass within watersheds where Jollyville Plateau salamander
populations are known to occur (COA 2003, pp. 1-7). Analysis of water
quality attributes conducted by the COA (1997, pp. 8-9) showed
significant differences in nitrate, ammonia, total dissolved solids,
total suspended solids, and turbidity concentrations between watersheds
dominated by golf courses, residential land, and rural land. Golf
course tributaries were found to have higher concentrations of these
constituents than residential tributaries, and both golf course and
residential tributaries had substantially higher concentrations for
these five water quality attributes than rural tributaries (COA 1997,
pp. 8-9).
Residential irrigation of wastewater effluent is another source
that leads to excessive nutrient input aquatic systems, as has been
identified in the recharge and contributing zones of the Barton Springs
Segment of the Edwards Aquifer (Ross 2011, pp. 11-18; Mahler et al.
2011, pp. 16-23). Wastewater effluent permits do not require treatment
to remove metals, pharmaceutical chemicals, or the wide range of
chemicals found in body care products, soaps, detergents, pesticides,
or other cleaning products (Ross 2011, p. 6). These chemicals remaining
in treated wastewater effluent can enter streams and the aquifer and
alter water quality within salamander habitat. A USGS study found
nitrate concentrations in Barton Springs and the five streams that
provide most of its recharge much higher during 2008 to 2010 than
before 2008 (USGS 2011, pp. 1-4). Additionally, nitrate levels in water
samples collected between 2003 and 2010 from Barton Creek tributaries
exceeded TCEQ screening levels and were identified as screening level
concerns (TCEQ 2012a, p. 344). The rapid development over the Barton
Springs contributing zone since 2000 was associated with an increase in
the generation of wastewater (Mahler et al. 2011, p. 29). Septic
systems and land-applied treated wastewater effluent are likely sources
contributing nitrate to the recharging streams (Mahler et al. 2011, p.
29).
As of November 2010, the permitted volume of irrigated flow in the
contributing zone of the Barton Springs Segment of the Edwards Aquifer
was 3,300,000 gallons (12,491 kiloliters) per day. About 95 percent of
that volume was permitted during 2005 to 2010 (Mahler et al. 2011, p.
30). As the human population is projected to increase by 377 percent in
the range of the Georgetown salamander and by 128 percent in the range
of the Salado salamander by 2050, we expect the permitted volume of
irrigated flow of wastewater effluent in the contributing zone of the
Northern Segment of the Edwards Aquifer to increase considerably.
Excessive nutrient input into aquatic systems can increase plant
growth (including algae blooms), which pulls more oxygen out of the
water when the dead plant matter decomposes, resulting in less oxygen
being available in the water for salamanders to breathe (Schueler 1987,
pp. 1.5-1.6; Ross 2011,
[[Page 10270]]
p. 7). A reduction in dissolved oxygen concentrations could not only
affect respiration in salamander species, but also lead to decreased
metabolic functioning and growth in juveniles (Woods et al. 2010, p.
544), or death (Ross 2011, p. 6). Excessive plant material can also
reduce stream velocities and increase sediment deposition (Ross 2011,
p. 7). When the interstitial spaces become compacted or filled with
fine sediment, the amount of available foraging habitat and protective
cover is reduced (Welsh and Ollivier 1998, p. 1,128).
Increased nitrate levels have been known to affect amphibians by
altering feeding activity and causing disequilibrium and physical
abnormalities (Marco et al. 1999, p. 2,837). Nitrate toxicity studies
have indicated that salamanders and other amphibians are sensitive to
these pollutants (Marco et al. 1999, p. 2,837). Some studies have
indicated that nitrate concentrations between 1.0 and 3.6 mg/L can be
toxic to aquatic organisms (Rouse 1999, p. 802; Camargo et al. 2005, p.
1,264; Hickey et al. 2009, pp. ii, 17-18). Nitrate concentrations have
been documented within this range (1.85 mg/L) at one Salado salamander
site (Lazy Days Fish Farm, which is reported as Critchfield Springs in
Norris et al. 2012, p. 14) and higher than this range (4.05 mg/L, 4.28
mg/L, and 4.21 mg/L) at three Salado salamander sites (Big Boiling,
Lil' Bubbly, and Robertson Springs, respectively) (Norris et al. 2012,
pp. 23-25). Likewise, nitrate samples taken at a Georgetown salamander
site (Swinbank Springs) were found to be as high as 3.32 mg/L (SWCA
2012, pp. 15, 20). For comparison, nitrate levels in undeveloped
Edwards Aquifer springs (watersheds without high levels of
urbanization) are typically close to 1 mg/L (O'Donnell et al. 2006, p.
26). From the information available on the effects of elevated nitrate
levels on amphibian species, we conclude that the salamanders at these
sites may be experiencing impairments to their respiratory, metabolic,
and feeding capabilities.
We also assessed the risk of exposure to sources of excessive
nutrient input for the Georgetown and Salado salamanders by examining
2012 Google Earth aerial imagery. For the 12 known surface sites of the
Georgetown salamander, we found 3 have golf courses; 3 have livestock;
and we assumed that 10 of the surface watersheds are accessible to
feral hogs given that they are common across the landscape and because
we could not identify any fencing that would exclude them from these
areas. In addition, we found that surface watersheds for six of the
seven known Salado salamander sites have livestock access. We also
assumed these six surface watersheds contain feral hogs.
The threat of water quality degradation from excessive nutrient
exposure alone (that is, without the consideration of additional threat
sources that may be present at specific sites) could cause irreversible
declines or extirpation in local populations or significant declines in
habitat quality of any of the Georgetown and Salado salamanders with
continuous or repeated exposure. In some instances, exposure to
excessive nutrient exposure could negatively impact a salamander
population in combination with exposure to other sources of water
quality degradation, resulting in significant habitat declines. The
City of Georgetown's water quality ordinance requires that permanent
structural water quality controls for regulated activities over the
Edwards Aquifer recharge zone must remove 85 percent of total suspended
solids for the entire project. This increases the amount of total
suspended solids that must be removed from projects within the City of
Georgetown and its ETJ by 5 percent over the existing requirements
(i.e. removal of 80 percent total suspended solids) found in the
Edwards Aquifer Rules. Although structural water quality controls are
generally less efficient at removing nutrients from stormwater, by
increasing the required removal of total suspended solids, the
implementation of the ordinance will result in an increase in the
amount of nutrients removed from stormwater. In addition, the ordinance
now requires stream buffers for all streams in the Edwards Aquifer
recharge zone within the City of Georgetown and its ETJ that drain more
than 64 ac (26 ha). These buffers are similar to those required under
similar water quality regulations in central Texas and will help reduce
the amount of nutrients and other pollutants that enter waterways.
However, we still consider excessive nutrient exposure to be an ongoing
threat of high impact for the Georgetown and Salado salamanders that is
likely to continue in the future.
Changes in Water Chemistry
Conductivity
Conductivity is a measure of the ability of water to carry an
electrical current and can be used to approximate the concentration of
dissolved inorganic solids in water that can alter the internal water
balance in aquatic organisms, affecting the four central Texas
salamanders' survival. Conductivity levels in the Edwards Aquifer are
naturally low, ranging from approximately 550 to 700 microsiemens per
centimeter ([mu]S cm-1) (derived from several conductivity
measurements in two references: Turner 2005, pp. 8-9; O'Donnell et al.
2006, p. 29). As ion concentrations, such as chlorides, sodium,
sulfates, and nitrates rise, conductivity will increase. These
compounds are the chemical products or byproducts of many common
pollutants that originate from urban environments (Menzer and Nelson
1980, p. 633), which are often transported to streams via stormwater
runoff from impervious cover. This combined with the stability of the
measured ions makes conductivity an excellent monitoring tool for
assessing the impacts of urbanization to overall water quality.
Conductivity can be influenced by weather. Rainfall serves to
dilute ions and lower conductivity while drought has the opposite
effect. The trends of increasing conductivity in urban watersheds were
evident under baseflow conditions and during a period when
precipitation was above average in all but 3 years, so drought was not
a factor (NOAA 2013, pp. 1-7). The COA also monitored water quality as
impervious cover increased in several subdivisions with known
Jollyville Plateau salamander sites between 1996 and 2007. They found
increasing ions (calcium, magnesium, and bicarbonate) and nitrates with
increasing impervious cover at four Jollyville Plateau salamander sites
and as a general trend during the course of the study from 1997 to 2006
(Herrington et al. 2007, pp. 13-14). These results indicate that
developed watersheds can alter the water chemistry within salamander
habitats.
High conductivity has been associated with declining salamander
abundance in a species that is closely related to the Georgetown and
Salado salamanders. For example, three of the four sites with
statistically significant declining Jollyville Plateau salamander
counts from 1997 to 2006 are cited as having high conductivity readings
(O'Donnell et al. 2006, p. 37). Similar correlations were shown in
studies comparing developed and undeveloped sites from 1996 to 1998
(Bowles et al. 2006, pp. 117-118). This analysis found significantly
lower numbers of salamanders and significantly higher measures of
specific conductance at developed sites as compared to undeveloped
sites (Bowles et al. 2006, pp. 117-118). Tributary 5 of Bull Creek has
had an increase in conductivity, chloride, and sodium and a decrease in
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invertebrate diversity from 1996 to 2008 (COA 2010b, p. 16). Only one
Jollyville Plateau salamander has been observed here from 2009 to 2010
in quarterly surveys (Bendik 2011a, p. 16). A separate analysis found
that ions such as chloride and sulfate increased in Barton Creek
despite the enactment of city-wide water quality control ordinances
(Turner 2007, p. 7). Poor water quality, as measured by high specific
conductance and elevated levels of ion concentrations, is cited as one
of the likely factors leading to statistically significant declines in
salamander counts at the COA's long-term monitoring sites (O'Donnell et
al. 2006, p. 46). Because the Jollyville Plateau salamander is similar
to the Georgetown and Salado salamanders with regard to morphology,
physiology, habitat requirements, and life history traits, we expect
similar declines of Georgetown and Salado salamanders as impervious
cover increases within Williamson and Bell Counties, Texas. The human
population is projected to increase by 377 percent in the range of the
Georgetown salamander and by 128 percent in the range of the Salado
salamander by 2050, so we expect that conductivity levels within the
areas where Georgetown and Salado salamander populations are known to
occur will increase the exposure of salamanders to this stressor.
The threat of water quality degradation from high conductivity
alone (that is, without the consideration of additional threat sources
that may be present at specific sites) could cause irreversible
declines or extirpation in local populations or significant declines in
habitat quality of the Georgetown and Salado salamanders with
continuous or repeated exposure. In some instances, exposure to high
conductivity could negatively impact a salamander population in
combination with exposure to other sources of water quality
degradation, resulting in significant habitat declines. Although the
best available information does not indicate that increased
conductivity is occurring within the ranges of the Georgetown and
Salado salamanders to date (SWCA 2012, p. 19), we expect this to become
a significant threat in the future for these species as urbanization
continues to expand within their surface watersheds.
Changes in Prey Base Community
As noted above, stressors from urbanization such as contaminants
can alter the invertebrate community of a water body by replacing
sensitive species with species that are more tolerant of pollution
(Schueler 1994, p. 104; Coles et al. 2012, pp. 4, 58). This shift in
community can have negative, indirect effects on Georgetown and Salado
salamander populations. Studies on closely related species of
salamanders have shown these predators to be sensitive to changes in
the species composition of their prey base. For example, Johnson and
Wallace (2005, pp. 305-306) found that when the Blue Ridge two-lined
salamander (Eurycea wilderae) fed on an altered composition of prey
species, salamander densities were lower compared to salamanders
feeding on an unaltered prey community. The researchers partly
attributed this difference in density to reduced larval growth caused
by the lack of nutrition in the diet (Johnson and Wallace 2005, p.
309). Another study on the Tennessee cave salamander (Gyrinophilus
palleucus) found the prey composition of salamanders within one cave
differed from another cave, and this difference resulted in significant
differences in salamander densities and biomass (Huntsman et al. 2011,
pp. 1750-1753). Based on this literature, we conclude that the species
composition of invertebrates is an important factor in determining the
health of Georgetown and Salado salamander populations. Although the
best available information does not indicate shifting invertebrate
communities within the ranges of the Georgetown and Salado salamanders,
we expect this to become a significant threat in the future for these
species as urbanization continues to expand within their surface
watersheds.
Water Quantity Degradation
Water quantity decreases and spring flow declines are considered
threats to Eurycea salamanders (Corn et al. 2003, p. 36; Bowles et al.
2006, p. 111) because drying spring habitats can cause salamanders to
be stranded, resulting in death of individuals (O'Donnell et al. 2006,
p. 16). It is also known that prey availability is low underground due
to the lack of primary production (Hobbs and Culver 2009, p. 392).
Therefore, relying entirely on subsurface habitat during dry conditions
on the surface may negatively impact the salamanders' feeding abilities
and slow individual and population growth. Ultimately, dry surface
conditions can exacerbate the risk of extirpation in combination with
other threats occurring at the site. In addition, water quantity
increases in the form of large spring discharge events and flooding may
impact salamander populations by flushing individuals downstream into
unsuitable habitat (Petranka and Sih 1986, p. 732; Barrett et al. 2010,
p. 2,003) or forcing individuals into subsurface habitat refuge (Bendik
2011b, COA, pers. comm.; Bendik and Gluesenkamp 2012, pp. 3-4). Below,
we evaluate the sources of water quantity alterations in Georgetown and
Salado salamander habitat.
Urbanization
Increased urbanization in the watershed has been cited as one
factor, particularly in combination with drought that causes
alterations in spring flows (COA 2006, pp. 46-47; TPWD 2011, pp. 4-5;
Coles et al. 2012. p. 10). This is partly due to increases in
groundwater pumping and reductions in baseflow due to impervious cover.
Urbanization removes the ability of a watershed to allow slow
filtration of water through soils following rain events. Instead
rainfall runs off impervious surfaces and into stream channels at
higher rates, increasing downstream ``flash'' flows and decreasing
groundwater recharge and subsequent baseflows from springs (Miller et
al. 2007, p. 74; Coles et al. 2012, pp. 2, 19). Urbanization can also
impact water quantity by increasing groundwater pumping and altering
the natural flow regime of streams. These stressors are discussed in
more detail below.
Urbanization can also result in increased groundwater pumping,
which has a direct impact on spring flows, particularly under drought
conditions. From 1980 to 2000, groundwater pumping in the Northern
Segment of the Edwards Aquifer nearly doubled (TWDB 2003, pp. 32-33).
Municipal wells within 500 ft (152 m) of San Gabriel Springs
(Georgetown salamander habitat) now flow in the summer only
intermittently due to pumping from nearby water wells (Booker 2011,
Service, pers. comm.). Georgetown salamanders have not been found there
since 1991 despite searches for them (Chippindale et al. 2000, p. 40;
Pierce 2011b, Southwestern University, pers. comm.).
Furthermore, water levels in Williamson County wells were lower in
2005 than in 1995 (Boghici 2011, pp. 28-29). The declining water levels
are attributed in part to groundwater pumping by industrial and public
supply users (Berehe 2005, p. 18). Pumpage from the Edwards Aquifer has
consistently exceeded the estimate available supply between 1985 and
1997 in Williamson County (Ridgeway and Petrini 1999, p. 35). Over a
50-year horizon (2001 to 2050), models predict a gradual long-term
water-level decline will occur in the Pflugerville-Round Rock-
Georgetown area of Williamson County (Berehe 2005, p. 2). There are 34
[[Page 10272]]
active public water supply systems in Williamson County (Berehe 2005,
pp. 3, 63). Through water conservation programs and other efforts to
meet new demands, TCEQ believes that water purveyors in Williamson
County can generally maintain their present groundwater systems (Berehe
2005, pp. 3, 63). In addition, all wholesale and retail water suppliers
are required to prepare and adopt drought contingency plans on TCEQ
rules (Title 30, Texas Administrative Code, Chapter 288) (Berehe 2005,
p. 64). However, there is no groundwater conservation district in place
with authority to control large-scale groundwater pumping for private
purposes (Berehe 2005, pp. 3, 63). Thus, groundwater levels may
continue to decline due to private pumping.
The City of Georgetown predicts the average water demand to
increase from 8.21 million gallons (30,000 kiloliters) per day in 2003,
to 10.9 million gallons (37,000 kiloliters) per day by 2030 (City of
Georgetown 2008, p. 3.36). Under peak flow demands (18 million gallons
[68,000 kiloliters] per day in 2003), the City of Georgetown uses seven
groundwater wells in the Edwards Aquifer (City of Georgetown 2008, p.
3.36). Total water use for Williamson County was 82,382 acre feet (ac
ft) in 2010, and is projected to increase to 109,368 ac ft by 2020, and
to 234,936 ac ft by 2060, representing a 185 percent increase over the
50-year period (TWDB 2011, p. 78). Similarly, Bell County predicts a 59
percent and 91 percent increase in total water use over the same 50-
year period, respectively (TWDB 2011, pp. 5, 72).
While the demand for water is expected to increase with human
population growth, future groundwater use in this area is predicted to
drop as municipalities convert from groundwater to surface water
supplies (TWDB 2003, p. 65). To meet the increasing water demand, the
2012 State Water Plan recommends more reliance on surface water,
including existing and new reservoirs, rather than groundwater (TWDB
2012, p. 190). For example, one recommended project conveys water from
Lake Travis to Williamson County (TWDB 2012, pp. 192-193). There is
also a recommendation to augment the surface water of Lake Granger in
Williamson County with groundwater from Burleson County and the
Carrizo-Wilcox Aquifer (TWDB 2012, pp. 164, 192-193). However, it is
unknown if this reduction in groundwater use will occur, and if it
does, how that will affect spring flows for salamanders. Water supply
from the Edwards Aquifer in Williamson and Bell Counties is projected
to remain the same through 2060 (Berehe 2005, p. 38; Hassan 2011, p.
7). The Georgetown City Manager has recently indicated that the City of
Georgetown will not use water from the Edwards Aquifer in plans for
future and additional municipal water supplies (Brandenburg 2013, pers.
comm). Instead, the City of Georgetown intends to use surface water or
non-Edwards wells for future sources of water.
The COA found a negative correlation between urbanization and
spring flows at Jollyville Plateau salamander sites (Turner 2003, p.
11). Field studies have also shown that a number of springs that
support Jollyville Plateau salamanders have already gone dry
periodically, and that spring waters resurface following rain events
(O'Donnell et al. 2006, pp. 46-47). Through a site-by-site assessment
from information available in our files and provided during the peer
review and public comment period for the proposed rule, we found that
at least 2 out of the 15 known Georgetown salamander surface sites and
3 out of the 7 known Salado salamander surface sites have gone dry for
some period of time. Because we lack flow data for some of the spring
sites, it is possible that even more sites have gone dry for a period
of time as well.
Flow is a major determining factor of physical habitat in streams,
which in turn, is a major determining factor of aquatic species
composition within streams (Bunn and Arthington 2002, p. 492). Various
land-use practices, such as urbanization, conversion of forested or
prairie habitat to agricultural lands, excessive wetland draining, and
overgrazing can reduce water retention within watersheds by routing
rainfall quickly downstream, increasing the size and frequency of flood
events and reducing baseflow levels during dry periods (Poff et al.
1997, pp. 772-773). Over time, these practices can degrade in-channel
habitat for aquatic species (Poff et al. 1997, p. 773).
Baseflow is defined as that portion of stream flow that originates
from shallow, subsurface groundwater sources, which provide flow to
streams in periods of little rainfall (Poff et al. 1997, p. 771). The
land-use practices mentioned above can cause stream flow to shift from
predominately base flow, which is derived from natural filtration
processes, to predominately stormwater runoff. For example, an
examination of 24 stream sites in the urbanized Austin area revealed
that increasing impervious cover in the watersheds resulted in
decreased base flow, increased high-flow events of shorter duration,
and more rapid rises and falls of the stream flow (Glick et al. 2009,
p. 9). Increases in impervious cover within the Walnut Creek watershed
(Jollyville Plateau salamander habitat) have likely caused a shift to
more rapid rises and falls of that stream flow (Herrington 2010, p.
11).
With increasing stormwater runoff, the amount of baseflow available
to sustain water supplies during drought cycles is diminished and the
frequency and severity of flooding increases (Poff et al. 1997, p.
773). The increased quantity and velocity of runoff increases erosion
and streambank destabilization, which in turn, leads to increased
sediment loadings, channel widening, and detrimental changes in the
morphology and aquatic ecology of the affected stream system (Hammer
1972, pp. 1,535-1,536, 1,540; Booth 1990, pp. 407-409, 412-414; Booth
and Reinelt 1993, pp. 548-550; Schueler 1994, pp. 106-108; Pizzuto et
al. 2000, p. 82; Center for Watershed Protection 2003, pp. 41-48; Coles
et al. 2012, pp. 37-38). The City of Georgetown's water quality
ordinance requires that regulated activities occurring on the Edwards
Aquifer recharge zone shall not cause any increase in the developed
flow rate of stormwater for the 2-year, 3-hour storm. Most
municipalities currently enforce this or a similar standard for new
developments, and it is unclear the effect this requirement will have
on the quantity and velocity of runoff from developments in Georgetown
or its ETJ.
Changes in flow regime can directly affect salamander populations.
For example, the density of aquatic southern two-lined salamanders
(Eurycea cirrigera) declined more drastically in streams with urbanized
watersheds compared to streams with forested or pastured watersheds in
Georgia (Barrett et al. 2010, pp. 2,002-2,003). A statistical analysis
indicated that this decline in urban streams was due to an increase in
flooding frequency from stormwater runoff. In artificial stream
experiments, salamander larvae were flushed from sand-based sediments
at significantly lower velocities, as compared to gravel, pebble, or
cobble-based sediments (Barrett et al. 2010, p. 2,003). This has also
been observed in the wild in small-mounted salamanders (Ambystoma
texanum) whereby large numbers of individuals were swept downstream
during high stream discharge events resulting in death by predation or
physical trauma (Petranka and Sih 1986, p. 732). We expect increased
flow velocities from impervious cover will cause the flushing of
Georgetown and Salado salamanders from their habitats.
The threat of water quantity degradation from urbanization could
cause irreversible declines in
[[Page 10273]]
population sizes or habitat quality for the Georgetown and Salado
salamanders. Also, it could cause irreversible declines or the
extirpation of a salamander population at a site with continuous
exposure. Although we do not consider water quantity degradation from
urbanization to be a significant threat to Georgetown and Salado
salamanders at the present time, we expect this threat to become
significant in the future as urbanization expands within these species'
surface watersheds.
Drought
Drought conditions cause lowered groundwater tables and reduced
spring flows. The Northern Segment of the Edwards Aquifer, which
supplies water to Georgetown and Salado salamander habitat, is
vulnerable to drought (Chippindale et al. 2000, p. 36). A drought
lasting from 2008 to 2009 was considered one of the worst droughts in
central Texas history and caused numerous salamander sites to go dry in
the central Texas region (Bendik 2011a, p. 31). An even more pronounced
drought throughout Texas began in 2010, with the period from October
2010 through September 2011 being the driest 12-month period in Texas
since rainfall records began (Hunt et al. 2012, p. 195). Rainfall in
early 2012 lessened the intensity of drought conditions, but 2012
monthly summer temperatures continued to be higher than average (NOAA
2013, p. 6). Moderate to extreme drought conditions continued into 2013
in the central Texas region (LCRA 2013, p. 1). Weather forecasts called
for near to slightly less than normal rainfall across Texas through
August 2013, but there was not enough rain to break the drought (LCRA
2013, p. 1). Year-end totals show that 2013 was the second lowest year
of inflows into the Highland Lakes region of central Texas since the
dams were built in the 1940s. There was some heavy rain in late-2013 in
central Texas but much of it fell in Austin or downstream of Austin
having little effect on recharging the Edwards Aquifer (LCRA 2014, p.
1).
The specific effects of low flow on the Georgetown and Salado
salamanders can be inferred by examining studies on the closely related
Barton Springs salamander. Drought decreases spring flow and dissolved
oxygen levels and increases temperature in Barton Springs (Turner 2004,
p. 2; Turner 2009, p. 14). Low dissolved oxygen levels decrease
reproduction in Barton Springs salamanders (Turner 2004, p. 6; 2009, p.
14). Turner (2009, p. 14) also found that Barton Springs salamander
counts decline with decreasing discharge. The number of Barton Springs
salamander observed during surveys decreased during a prolonged drought
from June 2008 through September 2009 (COA 2011, pp. 19, 24, 27). The
drought in 2011 also resulted in dissolved oxygen concentrations so low
that COA used an aeration system to maintain oxygenated water in Eliza
and Sunken Gardens Springs (Dries 2011, COA, pers. comm.).
The Georgetown and Salado salamanders may be able to persist
through temporary surface habitat degradation because of their ability
to retreat to subsurface habitat. Drought conditions are common to the
region, and the ability to retreat underground may be an evolutionary
adaptation of Eurycea salamanders to such natural conditions (Bendik
2011a, pp. 31-32). However, it is important to note that although
salamanders may survive a drought by retreating underground, this does
not necessarily mean they are resilient to long-term drought conditions
(particularly because sites may already be affected by other,
significant stressors, such as water quality declines). Studies on
other aquatic salamander species have reported decreased occupancy,
loss of eggs, decreased egg-laying, and extirpation from sites during
periods of drought (Camp et al. 2000, p. 166; Miller et al. 2007, pp.
82-83; Price et al. 2012b, pp. 317-319).
Dry surface conditions can affect salamanders by reducing their
access to food. Surface habitats are important for prey availability as
well as individual and population growth. Therefore, sites with
suitable surface flow and adequate prey availability are likely able to
support larger population densities (Bendik 2012, COA, pers. comm.).
Research on related salamander species, such as the grotto salamander
(Typhlotriton spelaeus) and the Oklahoma salamander (Eurycea
tynerensis), demonstrates that resource-rich surface habitat is
necessary for juvenile growth (Tumlison and Cline 1997, p. 105). Prey
availability for carnivores, such as the Georgetown and Salado
salamanders, is low underground due to the lack of sunlight and primary
production (Hobbs and Culver 2009, p. 392). Complete loss of surface
habitat may lead to the extirpation of predominately subterranean
populations that depend on surface flows for biomass input (Bendik
2012, COA, pers. comm.). In addition, length measurements taken during
a COA mark-recapture study at Lanier Spring demonstrated that
individual Jollyville Plateau salamanders exhibited negative growth
(shrinkage) during a 10-month period of retreating to the subsurface
from 2008 to 2009 (Bendik 2011b, COA, pers. comm.; Bendik and
Gluesenkamp 2012, pp. 3-4). The authors of this study hypothesized that
the negative growth could be the result of soft tissue contraction and/
or bone loss, but more research is needed to determine the physical
mechanism with which the shrinkage occurs (Bendik and Gluesenkamp 2012,
p. 5). Although this shrinkage in body length was followed by positive
growth when normal spring flow returned, the long-term consequences of
catch-up growth are unknown for these salamanders (Bendik and
Gluesenkamp 2012, pp. 4-5).
Therefore, threats to surface habitat at a given site may not
extirpate populations of these salamander species in the short term,
but this type of habitat degradation may severely limit population
growth and increase a population's overall risk of extirpation from
other stressors occurring in the surface watershed.
The threat of water quantity degradation from drought alone (that
is, without the consideration of additional threat sources that may be
present at specific sites) could cause irreversible declines in
population sizes or habitat quality for the Georgetown and Salado
salamanders. Also, it could negatively impact salamander populations in
combination with other threats and contribute to significant declines
in the size of the populations or habitat quality. For example, changes
in water quantity will have direct impacts on the quality of that water
in terms of concentrations of contaminants and pollutants. Therefore,
we consider water quantity degradation from drought to be a threat of
high impact for the Georgetown and Salado salamanders now and in the
future.
Climate Change
Our analyses under the Endangered Species Act include consideration
of ongoing and projected changes in climate. The terms ``climate'' and
``climate change'' are defined by the Intergovernmental Panel on
Climate Change (IPCC). The term ``climate'' refers to the mean and
variability of different types of weather conditions over time, with 30
years being a typical period for such measurements, although shorter or
longer periods also may be used (IPCC 2007a, p. 78). The term ``climate
change'' thus refers to a change in the mean or variability of one or
more measures of climate (for example, temperature or precipitation)
that persists for an extended period, typically decades or longer,
whether the change is due to natural variability,
[[Page 10274]]
human activity, or both (IPCC 2007a, p. 78).
According to the IPCC (2007b, p. 1), ``Warming of the climate
system is unequivocal, as is now evident from observations of increases
in global average air and ocean temperatures, widespread melting of
snow and ice, and rising global average sea level.'' Average Northern
Hemisphere temperatures during the second half of the 20th century were
very likely higher than during any other 50-year period in the last 500
years and likely the highest in at least the past 1300 years (IPCC
2007b, p. 1). It is very likely that from 1950 to 2012 cold days and
nights have become less frequent, and hot days and hot nights have
become more frequent on a global scale (IPCC 2013, p. 4). It is likely
that the frequency and intensity of heavy precipitation events has
increased over North America (IPCC 2013, p. 4).
The IPCC (2013, pp. 15-16) predicts that changes in the global
climate system during the 21st century are very likely to be larger
than those observed during the 20th century. For the next two decades
(2016 to 2035), a warming of 0.3 [deg]C (0.5[emsp14][deg]F) to 0.7
[deg]C (1.3[emsp14][deg]F) per decade is projected (IPCC 2013, p. 15).
Afterwards, temperature projections increasingly depend on specific
emission scenarios (IPCC 2007b, p. 6). Various emissions scenarios
suggest that by the end of the 21st century, average global
temperatures are expected to increase 0.3 [deg]C to 4.8 [deg]C
(0.5[emsp14][deg]F to 8.6[emsp14][deg]F), relative to 1986 to 2005
(IPCC 2013, p. 15). By the end of 2100, it is virtually certain that
there will be more frequent hot and fewer cold temperature extremes
over most land areas on daily and seasonal timescales, and it is very
likely that heat waves and extreme precipitation events will occur with
a higher frequency and intensity (IPCC 2013, pp. 15-16).
Global climate projections are informative, and, in some cases, the
only or the best scientific information available for us to use.
However, projected changes in climate and related impacts can vary
substantially across and within different regions of the world (for
example, IPCC 2007b, p. 9). Therefore, we use ``downscaled''
projections when they are available and have been developed through
appropriate scientific procedures, because such projections provide
higher resolution information that is more relevant to spatial scales
used for analyses of a given species (see Glick et al. 2011, pp. 58-61,
for a discussion of downscaling). With regard to our analysis for the
Georgetown and Salado species, downscaled projections are available.
Localized projections suggest the southwest may experience the
greatest temperature increase of any area in the lower 48 States (IPCC
2007b, p. 8). Temperature in Texas is expected to increase by up to 4.8
[deg]C (8.6[emsp14][deg]F) by the end of 2100 (Jiang and Yang 2012, p.
235). The IPCC also predicts that hot extremes and heat waves will
increase in frequency and that many semi-arid areas like the western
United States will suffer a decrease in water resources due to climate
change (IPCC 2007b, p. 8). Model projections of future climate in
southwestern North America show a transition to a more arid climate
that began in the late 20th and early 21st centuries (Seager et al.
2007, p. 1183). Milly et al. (2005, p. 349) project a 10 to 30 percent
decrease in stream flow in mid-latitude western North America by the
year 2050 based on an ensemble of 12 climate models. Based on
downscaling global models of climate change, Texas is expected to
receive up to 20 percent less precipitation in winters and up to 10
percent more precipitation in summers (Jiang and Yang 2012, p. 238).
However, most regions in Texas are predicted to become drier as
temperatures increase (Jiang and Yang 2012, pp. 240-242).
An increased risk of drought in Texas could occur if evaporation
exceeds precipitation levels in a particular region due to increased
greenhouse gases in the atmosphere (CH2M HILL 2007, p. 18). A reduction
of recharge to aquifers and a greater likelihood for more extreme
droughts, such as the droughts of 2008 to 2009 and 2011, were
identified as potential climate change-related impacts to water
resources (CH2M HILL 2007, p. 23). Extreme droughts in Texas are now
much more probable than they were 40 to 50 years ago (Rupp et al. 2012,
pp. 1053-1054).
Various changes in climate may have direct or indirect effects on
species. These effects may be positive, neutral, or negative, and they
may change over time, depending on the species and other relevant
considerations, such as interactions of climate with other variables
(for example, habitat fragmentation) (IPCC 2007a, pp. 8-14, 18-19).
Identifying likely effects often involves aspects of climate change
vulnerability analysis. Vulnerability refers to the degree to which a
species (or system) is susceptible to, and unable to cope with, adverse
effects of climate change, including climate variability and extremes.
Vulnerability is a function of the type, magnitude, and rate of climate
change and variation to which a species is exposed, its sensitivity,
and its adaptive capacity (IPCC 2007a, p. 89; see also Glick et al.
2011, pp. 19-22). There is no single method for conducting such
analyses that applies to all situations (Glick et al. 2011, p. 3). We
use our expert judgment and appropriate analytical approaches to weigh
relevant information, including uncertainty, in our consideration of
various aspects of climate change.
Climate change could compound the threat of decreased water
quantity at salamander spring sites. Recharge, pumping, natural
discharge, and saline intrusion of Texas groundwater systems could all
be affected by climate change (Mace and Wade 2008, p. 657). Although
climate change predictions on the Northern Segment of the Edwards
Aquifer are not available, the Southern Edwards Aquifer is predicted to
experience additional stress from climate change that could lead to
decreased recharge (Lo[aacute]iciga et al. 2000, pp. 192-193). In
addition, CH2M HILL (2007, pp. 22-23) identified possible effects of
climate change on water resources within the Lower Colorado River
Watershed (which contributes recharge to the Barton Springs Segment of
the Edwards Aquifer, just south of the range of the Georgetown and
Salado salamanders). We therefore conclude that the best available
evidence indicates that the Northern Segment of the Edwards Aquifer
will respond similarly to climate change as the rest of the Edwards
Aquifer.
Rainfall and ambient temperatures are factors that may affect
Georgetown and Salado salamander populations. Different ambient
temperatures in the season that rainfall occurs can influence spring
water temperature if aquifers have fast transmission of rainfall to
springs (Martin and Dean 1999, p. 238). Gillespie (2011, p. 24) found
that reproductive success and juvenile survivorship in the Barton
Springs salamander may be significantly influenced by fluctuations in
mean monthly water temperature. This study also found that groundwater
temperature is influenced by the season in which rainfall events occur
over the recharge zone of the aquifer. When recharging rainfall events
occur in winter when ambient temperature is low, mean monthly water
temperature within the aquatic habitat of this species can drop as low
as 65.5 [deg]F (18.6 [deg]C) and remain below the annual average
temperature of 70.1 [deg]F (21.2 [deg]C) for several months (Gillespie
2011, p. 24).
In summary, the threat of water quantity degradation from climate
change could negatively impact the Georgetown and Salado salamanders in
combination with other threats and
[[Page 10275]]
contribute to significant declines in population sizes or habitat
quality. We consider this to be a threat of moderate impact for the
Georgetown and Salado salamanders now and in the future.
Physical Modification of Surface Habitat
The Georgetown and Salado salamanders are sensitive to direct
physical modification of surface habitat from sedimentation,
impoundments, flooding, feral hogs, livestock, and human activities.
Direct mortality to salamanders can also occur as a result of these
stressors, such as being crushed by feral hogs, livestock, or humans.
Sedimentation
Elevated mobilization of sediment (mixture of silt, sand, clay, and
organic debris) is a stressor that occurs as a result of increased
velocity of water running off impervious surfaces (Schram 1995, p. 88;
Arnold and Gibbons 1996, pp. 244-245). Increased rates of stormwater
runoff also cause increased erosion through scouring in headwater areas
and sediment deposition in downstream channels (Booth 1991, pp. 93,
102-105; Schram 1995, p. 88). Waterways are adversely affected in urban
areas, where impervious cover levels are high, by sediment loads that
are washed into streams or aquifers during storm events. Sediments are
either deposited into layers or become suspended in the water column
(Ford and Williams 1989, p. 537; Mahler and Lynch 1999, p. 177).
Sediment derived from soil erosion has been cited as the greatest
single source of pollution of surface waters by volume (Menzer and
Nelson 1980, p. 632).
Excessive sediment from stormwater runoff is a threat to the
physical habitat of salamanders because it can cover substrates
(Geismar 2005, p. 2). Sediments suspended in water can clog gill
structures in aquatic animals, which can impair breathing and reduce
their ability to avoid predators or locate food sources due to
decreased visibility (Schueler 1987, p. 1.5). Excessive deposition of
sediment in streams can physically reduce the amount of available
habitat and protective cover for aquatic organisms, by filling the
interstitial spaces of gravel and rocks where they could otherwise
hide. As an example, a California study found that densities of two
aquatic salamander species were significantly lower in streams that
experienced a large infusion of sediment from road construction after a
storm event (Welsh and Ollivier 1998, pp. 1,118-1,132). The
vulnerability of the aquatic salamander species in this California
study was attributed to their reliance on interstitial spaces in the
streambed habitats (Welsh and Ollivier 1998, p. 1,128).
Excessive sedimentation has contributed to declines in Jollyville
Plateau salamander populations in the past. Monitoring by the COA found
that, as sediment deposition increased at several sites, salamander
abundances significantly decreased (COA 2001, pp. 101, 126).
Additionally, the COA found that sediment deposition rates have
increased significantly along one of the long-term monitoring sites
(Bull Creek Tributary 5) as a result of construction activities
upstream (O'Donnell et al. 2006, p. 34). This site has had significant
declines in salamander abundance, based on 10 years of monitoring, and
the COA attributes this decline to the increases in sedimentation
(O'Donnell et al. 2006, pp. 34-35). The location of this monitoring
site is within a large preserved tract. However, the headwaters of this
drainage are outside the preserve and the development in this area
increased sedimentation downstream and impacted salamander habitat
within the preserved tract.
Effects of sedimentation on the Georgetown and Salado salamanders
are expected to be similar to the effects on the Barton Spring
salamanders based on similarities in their ecology and life-history
needs. Barton Spring salamander population numbers are adversely
affected by high turbidity and sedimentation (COA 1997, p. 13).
Sediments discharge through Barton Springs, even during baseflow
conditions (not related to a storm event) (Geismar 2005, p. 12). Storms
can increase sedimentation rates substantially (Geismar 2005, p. 12).
Areas in the immediate vicinity of the spring outflows lack sediment,
but the remaining bedrock is sometimes covered with a layer of sediment
several inches thick (Geismar 2005, p. 5). Further, urban development
within the watersheds of Georgetown and Salado salamander sites will
increase sedimentation and degrade water quality in salamander habitat
both during and after construction activities. However, the City of
Georgetown's water quality ordinance requires that permanent structural
water quality controls for regulated activities over the Edwards
Aquifer recharge zone must remove 85 percent of total suspended solids
for the entire project. This increases the amount of total suspended
solids that must be removed from projects within the City of Georgetown
and its ETJ by 5 percent over the existing requirements (i.e. removal
of 80 percent total suspended solids) found in the Edwards Aquifer
Rules. Additional threats from sediments as a source of contaminants
were discussed in the ``Contaminants and Pollutants'' under the ``Water
Quality Degradation'' section above.
The threat of physical modification of surface habitat from
sedimentation by itself could cause irreversible declines in population
sizes or habitat quality for the Georgetown and Salado salamanders. It
could also negatively impact the species in combination with other
threats to contribute to significant declines. Although we do not
consider this to be an ongoing threat to the Georgetown and Salado
salamanders at the present time, we expect physical modification of
surface habitat from sedimentation to become a significant threat in
the future as urbanization expands within these species' surface
watersheds.
Impoundments
Impoundments can alter the Georgetown and Salado salamanders'
physical habitat in a variety of ways that are detrimental.
Impoundments can alter the natural flow regime of streams, increase
siltation, support larger, predatory fish (Bendik 2011b, COA, pers.
comm.), leading to a variety of impacts to the Georgetown and Salado
salamanders and their surface habitats. For example, a low water
crossing on a tributary of Bull Creek occupied by the Jollyville
Plateau salamander resulted in sediment build-up above the impoundment
and a scour hole below the impoundment that supported predaceous fish
(Bendik 2011b, COA, pers. comm.). As a result, Jollyville Plateau
salamanders were not found in this degraded habitat after the
impoundment was constructed. When the crossing was removed in October
2008, the sediment build-up was removed, the scour hole was filled, and
Jollyville Plateau salamanders were later observed (Bendik 2011b, COA,
pers. comm.).
Impoundments have also impacted some of the Georgetown and Salado
salamanders' surface habitats. Two sites for the Georgetown salamander
(Cobb Spring and Shadow Canyon) have spring openings that are
surrounded at least in part by brick and mortar impoundments (White
2011, SWCA, pers. comm.; Booker 2011, Service, pers. comm.), presumably
to collect the spring water for cattle. San Gabriel Springs is also
impounded with a substrate of aquarium gravel (Booker 2011, Service,
pers. comm.). However, the future threat of impoundments at occupied
Georgetown salamander sites has been reduced through the City of
[[Page 10276]]
Georgetown's water quality ordinance. The ordinance established a 984-
ft (300-m) buffer zone within which the construction of impoundments
would not be permitted. In addition, all springs within the City of
Georgetown or its ETJ will be protected by a 164-ft (50-m) buffer zone.
Two sites for the Salado salamander (Cistern Springs and Lazy Days Fish
Farm) have been modified by impoundments.
The threat of physical modification of surface habitat from
impoundments by itself may not be likely to cause significant
population declines, but it could negatively impact the Salado
salamander in combination with other threats and contribute to
significant declines in the population size or habitat quality. We
consider impoundments to be an ongoing threat of moderate impact to the
Salado salamander and their surface habitats that will continue in the
future. Due to the City of Georgetown's water quality ordinance, we do
not expect additional Georgetown salamander sites to be impounded in
the future.
Flooding
Flooding as a result of rainfall events can considerably alter the
substrate and hydrology of salamander habitat, negatively impacting
salamander populations and behavior (Rudolph 1978, p. 155). Extreme
flood events have occurred in the Georgetown and Salado salamanders'
surface habitats (Pierce 2011a, p. 10; TPWD 2011, p. 6; Turner 2009, p.
11; O'Donnell et al. 2005, p. 15). A flood in September 2010 modified
surface habitat for the Georgetown salamander in at least two sites
(Swinbank Spring and Twin Springs) (Pierce 2011a, p. 10). The
stormwater runoff caused erosion, scouring of the streambed channel,
the loss of large rocks, and the creation of several deep pools.
Georgetown salamander densities dropped dramatically in the days
following the flood (Pierce 2011a, p. 11). At Twin Springs, Georgetown
salamander densities increased some during the winter following the
flood and again within 2 weeks after habitat restoration took place
(returning large rocks to the spring run) in the spring of 2011 (Pierce
2011a, p. 11). Likewise, three storm events in 2009 and 2010 deposited
sediment and other material on top of spring openings at Salado Spring
(TPWD 2011, p. 6). The increased flow rate from flooding causes
unusually high dissolved oxygen concentrations, which may exert direct
or indirect, sub-lethal effects (reduced reproduction or foraging
success) on salamanders (Turner 2009, p. 11).
Salamanders also may be flushed from the surface habitat by strong
flows during flooding, which can result in death by predation or by
physical trauma, as has been observed in other aquatic salamander
species (Baumgartner et al. 1999, p. 36; Sih et al. 1992, p. 1,429).
Bowles et al. (2006, p. 117) observed no Jollyville Plateau salamanders
in riffle habitat at one site during high water velocities and
hypothesized that individual salamanders were either flushed downstream
or retreated to the subsurface. Rudolph (1978, p. 158) observed that
severe floods could reduce populations of five different species of
aquatic salamanders by 50 to 100 percent.
Flooding can alter the surface salamander habitat by deepening
stream channels, which may increase habitat for predaceous fish. Much
of the Georgetown and Salado salamanders' surface habitat is
characterized by shallow water depth (COA 2001, p. 128; Pierce 2011a,
p. 3). However, deep pools are sometimes formed within stream channels
from the scouring of floods. As water depth increases, the deeper pools
support more predaceous fish populations. However, several central
Texas Eurycea species are able to survive in deep water environments in
the presence of many predators. Examples include the San Marcos
salamander in Spring Lake, Eurycea species in Landa Lake, and the
Barton Springs salamander in Barton Springs Pool. All of these sites
have vegetative cover, which may allow salamanders to avoid predation.
Anti-predator behaviors may allow these species to co-exist with
predaceous fish, but the effectiveness of these behaviors may be
species-specific (reviewed in Pierce and Wall 2011, pp. 18-19), and
many of the shallow surface habitats of the Georgetown and Salado
salamanders do not have much vegetative cover.
The threat of physical modification of surface habitat from
flooding by itself may not be likely to cause significant population
declines, but it could negatively impact the species in combination
with other threats and contribute to significant declines in the
population size or habitat quality. We consider this to be a threat of
moderate impact to the Georgetown and Salado salamanders that will
likely increase in the future as urbanization and impervious cover
increases within the surface watersheds of these species, causing more
frequent and more intense flash flooding (see discussion in the
``Urbanization'' section under ``Water Quantity Degradation'' above).
Feral Hogs
Feral hogs are another source of physical habitat disturbance to
Georgetown and Salado salamander surface sites. There are between 1.8
and 3.4 million feral hogs in Texas, and the feral hog population in
Texas is projected to increase 18 to 21 percent every year (Texas A&M
University (TAMU) 2011, p. 2). Feral hogs prefer to live around moist
areas, including riparian areas near streams, where they can dig into
the soft ground for food and wallow in mud to keep cool (Mapson 2004,
pp. 11, 14-15). Feral hogs disrupt these ecosystems by decreasing plant
species diversity, increasing invasive species abundance, increasing
soil nitrogen, and exposing bare ground (TAMU 2012, p. 4). Feral hogs
negatively impact surface salamander habitat by digging and wallowing
in spring heads, which increases sedimentation downstream (O'Donnell et
al. 2006, pp. 34, 46). This activity can also result in direct
mortality of amphibians (Bull 2009, p. 243).
Feral hogs have become abundant in some areas where the Georgetown
and Salado salamanders occur. Evidence of hogs has been observed near
one Georgetown salamander site (Cobbs Spring) (Booker 2011, Service,
pers. comm.). The landowner of Cobbs Spring is actively trapping feral
hogs (Booker 2011, Service, pers. comm.), but the effectiveness of this
management has not been assessed. Feral hogs are also present in the
area of several Salado salamander sites. At least one private landowner
has fenced off three spring sites known to be occupied by the Salado
salamander (Cistern, Hog Hollow, and Solana Springs) (Glen 2012,
Sedgwick LLP, pers. comm.), which likely provides protection from feral
hogs at these sites.
The threat of physical modification of surface habitat from feral
hogs by itself may not be likely to cause significant population
declines, but it could negatively impact the Georgetown and Salado
salamanders in combination with other threats and contribute to
significant declines in the population size or habitat quality. We
consider physical modification of surface habitat from feral hogs to be
an ongoing threat of moderate impact to the Georgetown and Salado
salamanders that will likely continue in the future as the feral hog
population increases.
Livestock
Similar to feral hogs, livestock can negatively impact surface
salamander habitat by disturbing the substrate and increasing
sedimentation in the spring
[[Page 10277]]
run where salamanders are often found. Poorly managed livestock grazing
results in changes in vegetation (from grass-dominated to brush-
dominated), which leads to increased erosion of the soil profile along
stream banks (COA 1995, p. 3-59) and sediment in salamander habitat.
Evidence of trampling and grazing in riparian areas from cattle was
found at one Georgetown salamander site (Shadow Canyon) (White 2011,
SWCA, pers. comm.), and cattle are present on at least one other
Georgetown salamander site (Cobbs Spring). Cattle are also present on
lands where four Salado salamander sites occur (Gluesenkamp 2011c,
TPWD, pers. comm.; Texas Section Society for Range Management 2011, p.
2). However, a private landowner has fenced three spring sites where
Salado salamanders are known to occur (Cistern, Hog Hollow, and Cistern
Springs), which likely provide the salamander and its habitat
protection from the threat of livestock at these locations (Glen 2012,
Sedgwick LLP, pers. comm.).
We assessed the risk of exposure of the Georgetown and Salado
salamanders to the threat of physical habitat modification from
livestock by examining 2012 Google Earth aerial imagery. Because
livestock are so common across the landscape, we assumed that where
present, these animals have access to spring sites unless they are
fenced out. For our assessment, we assumed that unless we could
identify the presence of fencing or unless the site is located in a
densely urbanized area, livestock have access and present a threat of
physical habitat modification to as many as 9 of the 15 Georgetown
salamander surface sites and 1 of the 7 Salado salamander sites.
There is some management of livestock occurring that reduces the
magnitude of negative impacts. An 8,126-ac (3,288-ha) property in Bell
County with at least three Salado salamander sites (Cistern, Hog
Hollow, and Solana Springs) has limited its cattle rotation to a
maximum of 450 head (Texas Section Society for Range Management 2011,
p. 2), which is considered a moderate stocking rate. In addition, the
landowner of Cobbs Spring (a Georgetown salamander site) is in the
process of phasing out cattle on the property (Boyd 2011, Williamson
County Conservation Foundation, pers. comm.).
The threat of physical modification of surface habitat from
livestock by itself may not be likely to cause significant population
declines, but it could negatively impact the Georgetown and Salado
salamanders in combination with other threats and contribute to
significant declines in the population size or habitat quality,
particularly with repeated or continuous exposure. We consider
livestock to be an ongoing threat of moderate impact to the Georgetown
salamander because 9 of its 15 surface sites are likely affected. On
the other hand, because only 1 of the 7 Salado salamander surface sites
is exposed to livestock, we do not consider this to be a threat to the
Salado salamander now or in the future.
Other Human Activities
Some of the Georgetown and Salado salamander sites have been
directly modified by human-related activities. In the summer of 2008, a
spring opening at a Salado salamander site was covered with gravel
(Service 2010, p. 6). Although we received anecdotal information that
at least one salamander was observed at the site after the gravel was
dumped at Big Boiling Springs, the Service has no detailed information
on how the Salado salamander was affected by this action. Heavy
machinery is currently used in the riparian area of Big Boiling and
Lil' Bubbly Springs to clear out vegetation and maintain a grassy lawn
to the water's edge (Gluesenkamp 2011a, c, TPWD, pers. comm.), which
has led to erosion problems during flood events (TPWD 2011, p. 6). The
modification of springs for recreation or other purposes degrades
natural riparian areas, which are important for controlling erosion and
attenuating floodwaters in aquatic habitats.
Other recent human activities at Big Boiling Spring include pumping
water from the spring opening, contouring the substrate of the spring
environment, and covering spring openings with gravel (TPWD 2011, p.
4). In the fall of 2011, the outflow channels and edges of Big Boiling
and Lil' Bubbly Springs were reconstructed with large limestone blocks
and mortar. In addition, the U.S. Army Corps of Engineers issued a
cease and desist order to the Salado Chamber of Commerce in October
2011, for unauthorized discharge of dredged or fill material that
occurred in this area (Brooks 2011, U.S. Army Corps of Engineers, pers.
comm.). This order was issued in relation to the need for a section 404
permit under the Clean Water Act (33 U.S.C. 1251 et seq.). Also in
October 2011, a TPWD game warden issued a citation to the Salado
Chamber of Commerce due to the need for a sand and gravel permit from
the TPWD for these activities being conducted within TPWD's
jurisdiction (Heger 2012a, TPWD, pers. comm.). The citation was issued
because the Salado Chamber of Commerce had been directed by the game
warden to stop work within TPWD's jurisdiction until they obtained a
permit, which the Salado Chamber of Commerce did temporarily, but work
started again despite the game warden's directive (Heger 2012a, TPWD,
pers. comm.). A sand and gravel permit was obtained on March 21, 2012.
The spring run modifications were already completed by this date, but
further modifications in the springs were prohibited by the permit.
Additional work on the bank of Salado Creek upstream of the springs was
permitted and completed (Heger 2012b, TPWD, pers. comm.).
At the complex of springs occupied by the Georgetown salamander
within San Gabriel River Park, a thick bed of nonnative aquarium gravel
has been placed in the spring runs (TPWD 2011, p. 9). This gravel is
too small to serve as cover habitat and does not form the interstitial
spaces required for Georgetown salamanders. Georgetown salamanders have
not been observed here since 1991 (Chippindale et al. 2000, p. 40;
Pierce 2011b, Southwestern University, pers. comm.). Aquarium gravel
dumping has not been documented at any other Georgetown salamander
sites. The City of Georgetown's water quality ordinance establishes a
262-ft (80-m) no-disturbance zone around occupied sites within which
only limited activities such as maintenance of existing improvements,
scientific monitoring, and fences will be permitted. In addition, the
ordinance establishes a no-disturbance zone that extends 164 ft (50 m)
around all springs within the Edwards Aquifer recharge zone in
Georgetown and its ETJ. These measures will reduce the threat of
habitat modification as the result of human activities. Additionally,
for the Georgetown salamander, the Adaptive Management Working Group is
charged specifically with reviewing Georgetown salamander monitoring
data and new research over time and recommending improvements to the
ordinance that may be necessary to ensure that it achieves its stated
purposes. This Adaptive Management Working Group, which includes
representatives of the Service and TPWD, will also review and make
recommendations on the approval of any variances to the ordinance.
Frequent human visitation of sites occupied by the Georgetown and
Salado salamanders may negatively affect the species and their
habitats. The COA has documented disturbed vegetation, vandalism, and
the destruction of travertine deposits (fragile rock formations formed
by deposit of calcium carbonate on stream bottoms) by
[[Page 10278]]
pedestrian traffic at one of their Jollyville Plateau salamander
monitoring sites in the Bull Creek watershed (COA 2001, p. 21), and it
may have resulted in direct destruction of small amounts of the
salamander's habitat. Eliza Spring and Sunken Garden Spring, locations
for both the Barton Springs and Austin blind salamanders, also
experience vandalism despite the presence of fencing and signage (Dries
2011, COA, pers. comm.). Frequent human visitation can reduce the
amount of cover available for salamander breeding, feeding, and
sheltering. We are aware of impacts from recreational use at one
Georgetown salamander site (San Gabriel Springs) and two Salado
salamander sites (Big Boiling and Lil Bubbly Springs) (TPWD 2011, pp.
6, 9). However, as the human population is projected to increase by 377
percent in the range of the Georgetown salamander and by 128 percent in
the range of the Salado salamander by 2050, we expect more Georgetown
and Salado salamander sites will be negatively affected from frequent
human visitation.
The threat of physical modification of surface habitat from human
visitation, recreation, and alteration is not significantly affecting
the Georgetown and Salado salamanders now. However, we consider this
will be a threat of moderate impact in the future as the human
population increases in Williamson and Bell Counties.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
When considering the listing determination of species, it is
important to consider conservation efforts that are nonregulatory, such
as habitat conservation plans, safe harbor agreements, habitat
management plans, memorandums of understanding, or other voluntary
actions that may be helping to ameliorate stressors to the species'
habitat, but are not legally required. There have been a number of
efforts aimed at minimizing the habitat destruction, modification, or
curtailment of the salamanders' ranges. For example, the WCCF, a
nonprofit organization established by Williamson County in 2002, is
currently working to find ways to conserve endangered species and other
unlisted species of concern in Williamson County, Texas. This
organization held a Georgetown salamander workshop in November 2003, in
an effort to bring together landowners, ranchers, farmers, developers,
local and state officials, Federal agencies, and biologists to discuss
information currently known about the Georgetown salamander and to
educate the public on the threats faced by this species.
In a separate undertaking, and with the help of a grant funded
through section 6 of the Act, the WCCF developed the Williamson County
Regional Habitat Conservation Plan (HCP) to obtain a section
10(a)(1)(B) permit for incidental take of federally listed endangered
species in Williamson County, Texas. This HCP became final in October
2008. Although the Georgetown salamander was not a covered species in
the incidental take permit, the WCCF included some considerations for
the Georgetown salamander in the HCP. In particular, they included work
to conduct a status review of the Georgetown salamander, which is
currently underway. The WCCF began allocating funding for Georgetown
salamander research and monitoring beginning in 2010. The WCCF plans to
fund at least $50,000 per year for 5 years for monitoring, surveying,
and gathering baseline data on water quality and quantity at salamander
spring sites. They intend to use information gathered during this
status review to develop a conservation strategy for this species. A
portion of that funding supported mark-recapture studies of the
Georgetown salamander at two of its known localities (Twin Springs and
Swinbank Spring) in 2010 and 2011 (Pierce 2011a, p. 20) by Dr. Benjamin
Pierce of Southwestern University, who had already been studying the
Georgetown salamander for several years prior to this. Additional funds
have been directed at water quality assessments of at least two known
localities and efforts to find previously undiscovered Georgetown
salamander populations (Boyd 2011, WCCF, pers. comm.). We have received
water quality data on several Georgetown salamander locations (SWCA
2012, pp. 11-20) and the location of one previously undiscovered
Georgetown salamander population (Hogg Hollow Spring 2; Covey 2013,
pers. comm.) as a result of this funding.
The Service worked with the WCCF to develop the Williamson County
Regional HCP for several listed karst invertebrates, and it is also
expected to benefit the Georgetown salamander by lessening the
potential for water quality degradation where karst invertebrate
preserves are established in the surface watersheds of known Georgetown
salamander sites. As part of the Williamson County Regional HCP, the
WCCF has begun establishing preserves that are beneficial to karst
invertebrate species. In addition, the WCCF has purchased an easement
on the 64.4-ac (26.1-ha) Lyda tract (Cobbs Cavern) in Williamson County
through the Service's section 6 grant program. This section 6 grant was
awarded for the protection of listed karst invertebrate species;
however, protecting this land also benefits the Georgetown salamander.
Although the spring where salamanders are located was not included in
the easement, a portion of the contributing surface watershed was
included. For this reason, some water quality benefits to the
salamander are expected. In January 2008, the WCCF also purchased the
145-ac (59-ha) Twin Springs preserve area. This area contains one of
the sites known to be occupied by the Georgetown salamander. This
species is limited to 17 known localities, 2 of which (Cobbs Spring and
Twin Springs) have some amount of protection by the WCCF. The
population size of Georgetown salamanders at Cobbs Spring is unknown,
while the population size at Twin Springs is estimated to be 100 to 200
individuals (Pierce 2011a, p. 18). Furthermore, the surface watersheds
of both springs are currently only partially protected by the WCCF, and
there is uncertainty about where subsurface flows are coming from at
both sites and whether or not these subsurface areas are protected as
well.
In Bell County, the landowners of a 8,126-ac (3,288-ha) property
(Solana Ranch) with at least three Salado salamander sites along with
the landowner of another property (Robertson Ranch) that contains one
Salado salamander site have shown a commitment to natural resource
conservation and land stewardship practices that benefit the Salado
salamander. Neither ranch owner has immediate plans to develop their
land, which means that the Salado salamander is currently not faced
with threats from urbanization (see discussion above under Factor A) at
these four sites. Furthermore, in early 2013, the Texas Nature
Conservancy acquired funding to obtain a conservation easement over 256
acres (104 hectares) of the Solana Ranch that encompasses all three
spring outlets (Cistern, Hog Hollow, and Solana Springs) occupied by
Salado salamanders. This easement would permanently protect the area
around these springs from urban development. In addition, the Solana
Ranch has fenced off feral hogs and livestock around its three springs.
The conservation efforts implemented thus far for the Salado
salamander represent over half of the known spring sites occupied by
this species. This includes about 21 percent of the surface
[[Page 10279]]
watershed for the three Salado salamander sites is contained within the
Solana Ranch property boundary, and only 3 percent of the surface
watershed for the one Salado salamander site (Robertson Spring) is
contained within the Robertson Ranch property boundary. The efforts by
these landowners represent an important step toward the conservation of
the Salado salamander.
The remaining area of the surface watersheds and the recharge zone
for these springs is not contained within the properties and is not
protected from future development. Considering the projected growth
rates expected in Bell County (from 310,235 in 2010 to 707,840 in 2050,
a 128 percent increase over the 40-year period; Texas State Data Center
2012, p. 353), these four Salado salamander spring sites are still at
threat from the detrimental effects of urbanization that could occur
outside of these properties. Although the pattern of existing
infrastructure suggests that much of the urbanization will occur along
IH-35 and downstream of the three Solana Ranch springs, the threat of
development and urbanization continues into the future because more
than 75 percent of the surface watershed for these sites is located
outside the boundaries of these properties. There are no long-term,
binding conservation plans currently in place for either of these
properties as the conservation easement for Solana Ranch has not been
finalized. In addition, the regulations in place in Bell County are not
adequate to protect water quality within occupied watersheds or within
the Edwards Aquifer recharge zone.
Although these conservation efforts likely contribute water quality
benefits to surface flow, surface habitats can be influenced by land
use throughout the recharge zone of the aquifer that supplies its
spring flow. Furthermore, the surface areas influencing subsurface
water quality (that is draining the surface and flowing to the
subsurface habitat) is not clearly delineated for many of the sites
(springs or caves) for the Georgetown and Salado salamanders. Because
we are not able to precisely assess additional pathways for negative
impacts to the Georgetown and Salado salamanders to occur, many of
their sites may be affected by threats that cannot be mitigated through
the conservation efforts that are currently ongoing.
Conclusion of Factor A
Degradation of habitat, in the form of reduced water quality and
quantity and disturbance of spring sites (physical modification of
surface habitat), is the primary threat to the Georgetown and Salado
salamanders. This threat may affect only the surface habitat, only the
subsurface habitat, or both habitat types. In consideration of the
stressors currently impacting the salamander species and their habitats
along with their risk of exposure to potential sources of this threat,
we find the threat of habitat destruction and modification within the
ranges of the Georgetown and Salado salamanders to be of low severity
now, but will become significant in the future as the human population
is projected to increase by 377 percent in the range of the Georgetown
salamander and by 128 percent in the range of the Salado salamander by
2050.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
There is little available information regarding overutilization of
the Georgetown and Salado salamanders for commercial, recreational,
scientific, or educational purposes, although we are aware that some
individuals of these species have been collected from their natural
habitat for a variety of purposes. Collecting individuals from
populations that are already small enough to experience reduced
reproduction and survival due to inbreeding depression or become
extirpated due to environmental or demographic stochasticity and other
catastrophic events (see the discussion on small population sizes under
Factor E--Other Natural or Manmade Factors Affecting Its Continued
Existence below) can pose a risk to the continued existence of these
populations. Additionally, there are no regulations currently in place
to prevent or restrict the collections of salamanders from their
habitat in the wild for scientific or other purposes, and we know of no
plans within the scientific community to limit the amount or frequency
of collections at known salamander locations. We recognize the
importance of collecting for scientific purposes; such as for research,
captive assurance programs, taxonomic analyses, and museum collections.
However, removing individuals from small, localized populations in the
wild, without any proposed plans or regulations to restrict these
activities, could increase the population's vulnerability and decrease
its resiliency and ability to withstand stochastic events.
Currently, we do not consider overutilization from collecting
salamanders in the wild to be a threat by itself, but it may contribute
to significant population declines, and could negatively impact the
Georgetown and Salado salamanders in combination with other threats.
C. Disease or Predation
Chytridiomycosis (chytrid fungus) is a fungal disease that is
responsible for killing amphibians worldwide (Daszak et al. 2000, p.
445). The chytrid fungus has been documented on the feet of Jollyville
Plateau salamanders from 15 different sites in the wild (O'Donnell et
al. 2006, pp. 22-23; Gaertner et al. 2009, pp. 22-23) and on Austin
blind salamanders in captivity (Chamberlain 2011, COA, pers. comm.).
However, the Austin blind and Jollyville Plateau salamanders did not
display any noticeable health effects (O'Donnell et al. 2006, p. 23).
We do not consider chytridiomycosis to be a threat to the Georgetown
and Salado salamanders at this time. The best available information
does not indicate that impacts from this disease on the Georgetown or
Salado salamander may increase or decrease in the future, and
therefore, we conclude that this disease is not a threat to either
species.
Regarding predation, COA biologists found Jollyville Plateau
salamander abundances were negatively correlated with the abundance of
predatory centrarchid fish (carnivorous freshwater fish belonging to
the sunfish family), such as black bass (Micropterus spp.) and sunfish
(Lepomis spp.) (COA 2001, p. 102). Predation of a Jollyville Plateau
salamander by a centrarchid fish was observed during a May 2006 field
survey (O'Donnell et al. 2006, p. 38). The Georgetown and Salado
salamanders have been observed retreating into gravel substrate after
cover was moved, suggesting these salamanders display anti-predation
behavior (Bowles et al. 2006, p. 117). Studies have found that San
Marcos salamanders (Eurycea nana) and Barton Springs salamanders both
have the ability to recognize and show anti-predator response to the
chemical cues of introduced and native centrarchid fish predators (Epp
and Gabor 2008, p. 612; DeSantis et al. 2013, p. 294). However, the
best available information does not indicate that predation of the
Georgetown and Salado salamanders is significantly limiting these
species.
In summary, while disease and predation may be affecting
individuals of these salamander species, these are not significant
factors affecting the species. Neither disease nor predation is
occurring at a level that we consider to be a threat to the Georgetown
and Salado salamanders now or in the future.
[[Page 10280]]
D. The Inadequacy of Existing Regulatory Mechanisms
The primary threats to the Georgetown and Salado salamanders are
habitat degradation related to a reduction of water quality and
quantity and disturbance at spring sites that will increase in the
future as human populations continue to grow and urbanization
increases. The human population in Georgetown is expected to grow by
375 percent between 2000 and 2033 (City of Georgetown 2008, p. 3.5).
The Texas State Data Center also estimates a 377 percent increase in
human population in Williamson County from 2010 to 2050. Population
projections from the Texas State Data Center (2012, p. 353) estimate
that Bell County, where the Salado salamander resides, will increase in
population by 128 percent over the same 40-year period. Therefore,
regulatory mechanisms that protect water quality and quantity of the
Edwards Aquifer from development related impacts are crucial to the
future survival of these species. Federal, State, and local laws and
regulations have been insufficient to prevent past and ongoing impacts
to the habitat of Georgetown and Salado salamanders from water quality
degradation, reduction in water quantity, and surface disturbance of
spring sites. They are unlikely to prevent further impacts to the
Salado salamander in the future. The new ordinance approved by the
Georgetown City Council in December 2013 is intended to reduce the
threats to the Georgetown salamander in the future and is discussed in
detail below.
State and Federal Regulations
Laws and regulations pertaining to endangered or threatened animal
species in the state of Texas are contained in Chapters 67 and 68 of
the Texas Parks and Wildlife Department Code and Sections 65.171-65.176
of Title 31 of the Texas Administrative Code (T.A.C.). TPWD regulations
prohibit the taking, possession, transportation, or sale of any of the
animal species designated by State law as endangered or threatened
without the issuance of a permit. The Georgetown and Salado salamanders
are not listed on the Texas State List of Endangered or Threatened
Species (TPWD 2013, p. 3). Therefore, these species are receiving no
direct protection from State of Texas regulations.
Under authority of the T.A.C. (Title 30, Chapter 213), the TCEQ
regulates activities having the potential for polluting the Edwards
Aquifer and hydrologically connected surface streams through the
Edwards Aquifer Protection Program or ``Edwards Rules.'' The Edwards
Rules require a number of water quality protection measures for new
development occurring in the recharge, transition, and contributing
zones of the Edwards Aquifer. The Edwards Rules were enacted to protect
existing and potential uses of groundwater and maintain Texas Surface
Water Quality Standards. Specifically, a water pollution abatement plan
(WPAP) must be submitted to the TCEQ in order to conduct any
construction-related or post-construction activities on the recharge
zone. The WPAP must include a description of the site and location
maps, a geologic assessment conducted by a geologist, and a technical
report describing, among other things, temporary and permanent best
management practices (BMPs) designed to reduce pollution related
impacts to nearby water bodies.
The permanent BMPs and measures identified in the WPAP are
designed, constructed, operated, and maintained to remove at least 80
percent of the incremental increase in annual mass loading of total
suspended solids from the site caused by the regulated activity (TCEQ
2005, p. 3-1). The use of this standard results in some level of water
quality degradation since up to 20 percent of total suspended solids
are ultimately discharged from the site into receiving waterways (for
example, creeks, rivers, lakes). Furthermore, this standard does not
address the concentration of dissolved pollutants, such as nitrates,
chloride, pesticides, and other contaminants shown to have detrimental
impacts on salamander biology. Separate Edwards Aquifer protection
plans are required for organized sewage collection systems, underground
storage tank facilities, and aboveground storage tank facilities.
Regulated activities exempt from the requirements of the Edwards Rules
are: (1) The installation of natural gas lines; (2) the installation of
telephone lines; (3) the installation of electric lines; (4) the
installation of water lines; and (5) the installation of other utility
lines that are not designed to carry and will not carry pollutants,
stormwater runoff, sewage effluent, or treated effluent from a
wastewater treatment facility.
Under the Edwards Rules, temporary erosion and sedimentation
controls are required to be installed and maintained during
construction for any exempted activities located on the recharge zone.
Individual land owners who seek to construct single-family residences
on sites are exempt from the Edwards Aquifer protection plan
application requirements provided the plans do not exceed 20 percent
impervious cover. Similarly, the Executive Director of the TCEQ may
waive the requirements for permanent BMPs for multifamily residential
subdivisions, schools, or small businesses when 20 percent or less
impervious cover is used at the site.
The jurisdiction of the Edwards Rules does not extend into Bell
County (TCEQ 2001, p. 1), which is where all seven of the known Salado
salamander populations are located. Therefore, many salamander
populations do not directly benefit from these protections. The Service
recognizes that implementation of the Edwards Rules in northern
Williamson County has the potential to positively influence conditions
at some spring sites occupied by the Salado salamander in southern Bell
County. However, all seven occupied sites and more than half of the
associated surface watersheds are located within Bell County and
receive no protection from the Edwards Rules.
The Edwards Rules provide some benefit to water quality, however,
they were not designed to remove all types of pollutants and they still
allow impacts to basic watershed hydrology, chemistry, and biology. The
Edwards Rules do not address land use, impervious cover limitations,
some nonpoint-source pollution, or application of fertilizers and
pesticides over the recharge zone (30 TAC 213.3). They also do not
contain requirements for stream buffers, surface buffers around
springs, or the protection of stream channels from erosion, all of
which would help to minimize water quality degradation in light of
projected human population growth in Williamson and Bell Counties. In
addition, the purpose of the Edwards Rules is to ``. . . protect
existing and potential uses of groundwater and maintain Texas Surface
Water Quality Standards'', which may not be entirely protective of the
Georgetown and Salado salamanders. We are unaware of any State or
Federal water quality regulations that are more restrictive than the
TCEQ's Edwards Rules in Bell or Williamson Counties outside the City of
Austin.
Texas has an extensive program for the management and protection of
water that operates under State statutes and the Federal Clean Water
Act (CWA). It includes regulatory programs such as the following: Texas
Pollutant Discharge Elimination System (to control point-source
pollution), Texas Surface Water Quality Standards (to protect
designated uses like recreation or aquatic life), and Total Maximum
Daily Load Program (under Section 303(d) of the CWA) (to
[[Page 10281]]
reduce pollution loading for impaired waters)
In 1998, the State of Texas assumed the authority from the
Environmental Protection Agency (EPA) to administer the National
Pollutant Discharge Elimination System. As a result, the TCEQ's TPDES
program has regulatory authority over discharges of pollutants to Texas
surface water, with the exception of discharges associated with oil,
gas, and geothermal exploration and development activities, which are
regulated by the Railroad Commission of Texas. In addition, stormwater
discharges as a result of agricultural activities are not subject to
TPDES permitting requirements. The TCEQ issues two general permits that
authorize the discharge of stormwater and non-stormwater to surface
waters in the State associated with: (1) Small municipal separate storm
sewer systems (MS4) (TPDES General Permit TXR040000) and (2)
construction sites (TPDES General Permit TXR150000). The MS4
permit covers small municipal separate storm sewer systems that were
fully or partially located within an urbanized area, as determined by
the 2000 Decennial Census by the U.S. Bureau of Census, and the
construction general permit covers discharges of stormwater runoff from
small and large construction activities impacting greater than 1 acre
of land. In addition, both of these permits require new discharges to
meet the requirements of the Edwards Rules.
To be covered under the MS4 general permit, a municipality must
submit a Notice of Intent (NOI) and a copy of their Storm Water
Management Program (SWMP) to TCEQ. The SWMP must include a description
of how that municipality is implementing the seven minimum control
measures, which include the following: (1) Public education and
outreach; (2) public involvement and participation; (3) detection and
elimination of illicit discharges; (4) construction site stormwater
runoff control (when greater than 1 ac (0.4 ha) is disturbed); (5)
post-construction stormwater management; (6) pollution prevention and
good housekeeping for municipal operations; and (7) authorization for
municipal construction activities (optional). The City of Georgetown
and the Village of Salado were not previously considered urbanized
areas and covered under the MS4 general permit. Therefore, they were
not operating under a SWMP authorized by TCEQ. However, the City of
Georgetown is now considered a small MS4 under the new TPDES general
permit and must develop and implement a Storm Water Management Program
(SWMP) within five years (TCEQ 2013, p. 22).
To be covered under the construction general permit, an applicant
must prepare a stormwater pollution and prevention plan (SWP3) that
describes the implementation of practices that will be used to
minimize, to the extent practicable, the discharge of pollutants in
stormwater associated with construction activity and non-stormwater
discharges. For activities that disturb greater than 5 ac (2 ha), the
applicant must submit an NOI to TCEQ as part of the approval process.
As stated above, the two general permits issued by the TCEQ do not
address discharge of pollutants to surface waters from oil, gas, and
geothermal exploration and geothermal development activities,
stormwater discharges associated with agricultural activities, and from
activities disturbing less than 5 acres (2 ha) of land. Despite the
significant value the TPDES program has in regulating point-source
pollution discharged to surface waters in Texas, it does not adequately
address all sources of water quality degradation, including nonpoint-
source pollution and the exceptions mentioned above, that have the
potential to negatively impact the Georgetown and Salado salamanders.
In reviewing the 2012 Texas Water Quality Integrated Report
prepared by the TCEQ, the Service identified 5 of 9 (56 percent) stream
segments located within surface watersheds occupied by the Georgetown
and Salado salamanders where parameters within water samples exceeded
screening level criteria (TCEQ 2012b, pp. 646-736). The analysis of
surface water quality monitoring data collected by TCEQ indicated
``screening level concerns'' for nitrate, dissolved oxygen, and
impaired benthic communities. The TCEQ screening level for nitrate
(1.95 mg/L) is within the range of concentrations (1.0 to 3.6 mg/L)
above which the scientific literature indicates may be toxic to aquatic
organisms (Camargo et al. 2005, p. 1,264; Hickey and Martin 2009, pp.
ii, 17-18; Rouse 1999, p. 802). In addition, the TCEQ screening level
for dissolved oxygen (5.0 mg/L) is similar to that recommended by the
Service in 2006 to be protective of federally listed salamanders (White
et al. 2006, p. 51). The Service also received baseline water quality
data from grab samples (that is, samples collected at one point in
time) collected during the summer of 2012 at four springs (Hogg Hollow,
Swinbank, Cedar Breaks Hiking Trail, and Cobb Springs) occupied by the
Georgetown salamander (SWCA 2012, pp. 11-20). Of these four samples,
one sample (collected from Swinbank Springs) had nitrate levels that
exceeded the TCEQ screening level, and one sample (collected from Cedar
Breaks Hiking Trail Spring) exceeded the TCEQ screening levels for E.
coli and fecal coliform bacteria. Therefore, water quality data
collected and analyzed by the TCEQ and specific water quality data
collected by SWCA at springs occupied by the Georgetown salamander
support our concern with the adequacy of existing regulations to
protect the Georgetown and Salado salamanders from the effects of water
quality degradation.
The TCEQ and Service jointly developed voluntary water quality
protection measures, also known as Optional Enhanced Measures, for
developers to implement that would minimize water quality effects to
springs systems and other aquatic habitats within the Edwards Aquifer
region of Texas by providing a higher level of water quality protection
(TCEQ 2005, p. i). In February 2005, the Service concurred that these
measures, if implemented, would protect several aquatic species,
including the Georgetown, Barton Springs, and San Marcos salamanders
from ``take under Section 9 of the Act'' due to water quality
degradation resulting from development in the Edwards Aquifer (TCEQ
2007, p. 1). This concurrence does not cover projects that: (1) Occur
outside the area regulated under the Edwards Rules; (2) result in water
quality impacts that may affect federally listed species not
specifically named above; (3) result in impacts to federally listed
species that are not water quality related; or (4) occur within 1 mile
(1.6 km) of spring openings that provide habitat for federally listed
species.
These ``Optional Enhanced Measures'' were intended to be used for
the purpose of avoiding take to the identified species from water
quality impacts, and they do not address any of the other threats to
the Georgetown or Salado salamanders. Due to the voluntary nature of
the measures, the Service does not consider them to be a regulatory
mechanism. In addition, TCEQ reported that only 17 Edwards Aquifer
applications have been approved under the Optional Enhanced Measures
between February 2005 and May 2012, and the majority of these
applications were for sites in the vicinity of Dripping Springs, Texas,
which is outside the range of the Georgetown and Salado salamanders
(Beatty 2012, TCEQ, pers. comm.).
Quarry operation is a regulated activity under the Edwards Aquifer
Rules (Title 30, Texas Administrative Code, Chapter 213, or 30 TAC 213)
and
[[Page 10282]]
owners must apply to the TCEQ in order to create or expand a quarry
located in the recharge or contributing zone of the Edwards Aquifer.
However, as stated above, the jurisdiction of the Edwards Rules does
not extend into Bell County (TCEQ 2001, p. 1), which is where all seven
of the known Salado salamander populations are located. TCEQ conducted
an inventory of rock quarries in 2004 (Berehe 2005, pp. 44-45). Out of
the TCEQ inventoried quarries statewide, 40 quarry sites were
inventoried in Burnet, Travis and Williamson counties. More than half
of these sites in the study area had no permit or were violating the
minimum standards of their permits either by an unauthorized discharge
of sediment or by air quality violation. (Berehe 2005, pp. 44-45)
In 2012, TCEQ produced a guidance document outlining recommended
measures specific for quarry operations (Barrett and Eck 2012, entire).
These measures include spill response measures, separating quarry-pit
floor from the groundwater level, setbacks and buffers for sensitive
recharge features and streams, creating berms to protect surface runoff
water from draining into quarry pits, and safely storing and moving
fuel (Barrett and Eck 2012, pp. 1-17). Quarry operators can seek
variances, exceptions, or revisions to these recommendations based on
site-specific facts (Barrett and Eck 2012, p. 1). This clarifying
guidance document could aid in protecting Georgetown salamander habitat
from the threat of quarry activities if quarry operators implement the
recommended measures, but future study is needed to determine how
quarry sites in Williamson County are complying with the Edwards Rules.
Local Ordinances
The Service has reviewed ordinances administered by each of the
municipalities and counties to determine if they contain measures
protective of salamanders above and beyond those already required
through other regulatory mechanisms (Clean Water Act, T.A.C., etc.).
The City of Georgetown has standards, such as impervious cover
limits, that relate to the protection of water quality. According to
Chapter 11 of the Georgetown Unified Development Code, impervious cover
limits have been adopted to minimize negative flooding effects from
stormwater runoff and to control, minimize, and abate water pollution
resulting from urban runoff. The impervious cover limits and stormwater
control requirements apply to all development in the City of Georgetown
and its extraterritorial jurisdiction. Impervious cover limits are as
high as 70 percent for small commercial developments to as low as 40
percent for some single family residential developments within its
extraterritorial jurisdiction.
The Georgetown City Council approved the Edwards Aquifer Recharge
Zone Water Quality Ordinance on December 20, 2013 (Ordinance No. 2013-
59). The purpose of this ordinance is to reduce the principal threats
to the Georgetown salamander within the City of Georgetown and its
extraterritorial jurisdiction through the protection of water quality
near occupied sites, enhancement of water quality protection throughout
the Edwards Aquifer recharge zone, and establishment of protective
buffers around all springs and streams. Specifically, the primary
conservation measures that will be implemented within the Edwards
Aquifer recharge zone include: (1) A requirement for geological
assessments to identify all springs and streams on a development site;
(2) the establishment of a no-disturbance zone that extends 262 ft (80
m) upstream and downstream from sites occupied by Georgetown
salamanders; (3) the establishment of a zone that extends 984 ft (300
m) around all occupied sites within which development is limited to
Residential Estate and Residential Low Density District as defined in
the City of Georgetown's Unified Development Code; (4) the
establishment of a no-disturbance zone that extends 164 ft (50 m)
around all springs; (5) the establishment of stream buffers for streams
that drain more than 64 acres (26 hectares); and (6) a requirement that
permanent structural water quality controls (BMPs) remove eighty-five
percent (85 percent) of total suspended solids for the entire project
which is an increase of 5 percent above what was previously required
under the Edwards Aquifer Rules.
As required by the new ordinance, the City of Georgetown adopted
the Georgetown Water Quality Management Plan, which will implement many
of the minimum control measures required under the TPDES general permit
for small municipal separate storm sewer systems (MS4) (see above
discussion). Because the City of Georgetown is considered a small MS4
under the new TPDES general permit, they are required to develop and
implement a Storm Water Management Program (SWMP) and the associated
minimum control measures within 5 years (TCEQ 2013, p. 22). However,
the City of Georgetown has committed to developing minimum control
measures under their Water Quality Management Plan within 6 months
(City of Georgetown 2013, p. 1). In addition, the Williamson County
Conservation Foundation (WCCF) also recently adopted an adaptive
management plan as part of their overall conservation plan for the
Georgetown salamander (WCCF 2013, p. 1). This plan will enable the
continuation and expansion of water quality monitoring, conservation
efforts, and scientific research to conserve the Georgetown salamander.
As discussed above under Factor A, habitat modification, in the
form of degraded water quality and quantity and disturbance of spring
sites, has been identified as the primary threat to the Georgetown
salamander. The ordinance and associated documents approved by the
Georgetown City Council reduce some of the threats from water quality
degradation and disturbance at spring sites. Specifically, water
quality threats have been reduced by requiring permanent structural
water quality controls in developments to remove eighty-five percent
(85 percent) of total suspended solids from the entire site. Previous
regulations, under TCEQ's Edwards Rules, do not require existing
impervious cover on a site to be included in the calculation of total
suspended solids and only require eighty percent (80 percent) of total
suspended solids be removed.
The new ordinance increases the required amount of total suspended
solids that must be removed from stormwater leaving a development site.
In addition, requirements for stream buffers and surface buffers around
springs reduces water quality degradation by providing vegetated
filters that can assist in the further removal of sediments and
pollutants from stormwater. Surface buffers around occupied sites will
minimize the possibility that the physical disturbance of salamander
habitat will occur as the result of construction activities. The
ordinance permits Residential Estate and Residential Low Density
District residential uses to occur as close as 262 ft (80 m) from
occupied Georgetown salamander sites and does not limit the type of
development that can occur outside of the 984-ft (300-m) buffer. The
ordinance also requires that roadways or expansions to existing
roadways that provide a capacity of 25,000 vehicles per day shall
provide for spill containment as described in the TCEQ's Optional
Enhanced Measures. This will reduce some of the future impacts to
salamander habitat by preventing some hazardous spills from entering
water bodies.
Five developments within the City of Georgetown or its ETJ are
exempted
[[Page 10283]]
from the requirements of the new ordinance because they were platted
before the ordinance was approved. The plats for these developments
show lots and other development activities proposed or currently
occurring within 984 ft (300 m), and for some within 262 ft (80 m), of
six occupied Georgetown salamander sites (Shadow Canyon Spring, Cowan
Spring, Bat Well Cave, Water Tank Cave, Knight Spring and Cedar Breaks
Hiking Trail) (Covey 2014, pers. comm.). Although some of these
developments appear to avoid the no-disturbance zone (262 ft (80 m)),
we were not provided enough information to determine if all or some of
the requirements of the ordinance would be met by each of the
developments as planned. According to the County, it does appear that
these developments meet the intent of the ordinance (Covey 2014, pers.
comm.)
There are no additional standards specifically related to water
quality required by Bell or Williamson Counties or for development
within the Village of Salado.
Groundwater Conservation Districts
The Clearwater Underground Water Conservation District (CUWCD) is
responsible for managing groundwater resources within Bell County. They
are statutorily obligated under Chapter 36 of the Texas Water Code to
regulate water wells and groundwater withdrawals that have the
potential to impact spring flow and aquifer levels. The CUWCD adopted a
desired future condition (that is, goal) for the Edwards Aquifer in
Bell County as the maintenance of at least 100 acre-feet (123,348 cubic
meters) per month of spring flow in Salado Creek under conditions
experienced during the drought of record in Bell County (Aaron 2012,
CUWCD, pers. comm.). The CUWCD has also developed a Drought Management
Plan that requires staff to monitor discharge values and determine when
the CUWCD needs to declare a particular drought stage, from Stage 1
``Awareness'' to Stage 4 ``Critical'' (Aaron 2012, CUWCD, pers. comm.).
However, water conservation goals and reduction of use for each drought
stage are voluntary.
One of the two gauges (FM 2843 bridge) used by the CUWCD to monitor
Salado Springs discharge measured no surface flow in 6 of 15 months
during the period of time between November 2011 and January 2013 (Aaron
2013, CUWCD, pers. comm.). In addition, during visits to Salado
salamander sites Service personnel observed no surface flow at
Robertson Springs (September 2011 and April 2013) and Lil' Bubbly
Springs (April 2013 and July 2013). Despite the documented loss of flow
in areas where the Salado salamander occurs, the desired future
condition of 100 ac-ft (123,348 cubic meters) per month as measured by
the CUWCD was exceeded throughout this timeframe. The Service
recognizes the desired future condition adopted by the CUWCD as a
valuable tool for protecting groundwater; however, it is not adequate
to ensure spring flow at all sites occupied by the Salado salamander.
Williamson County does not currently have a groundwater
conservation district that can manage groundwater resources countywide.
A 1990 study by the TCEQ and TWDB determined that Williamson County did
not meet the criteria to be designated as a ``critical area'' primarily
because of the availability of surface water supplies to meet projected
needs (Berehe 2005, p. 1). In 2005, TCEQ again declined to designate
Williamson County a priority groundwater management area, which would
lead to the creation of a groundwater conservation district (Berehe
2005, p. 3). This decision was based on TCEQ's opinion that Williamson
County's water supply concerns are mostly solved with current
management strategies to increasingly rely on surface water (as laid
out in TWDB 2012, p. 190) (Berehe 2005, p. 3). The City Manager has
recently indicated that the City of Georgetown will not use water from
the Edwards Aquifer in plans for future and additional municipal water
supplies (Brandenburg 2013, p .1). Instead, the City of Georgetown
intends to use surface water or non-Edwards wells for future sources of
water.
TCEQ noted that nearly all of Williamson County is within
certificated water purveyor service areas, and through conservation
programs and efforts to meet new demands with surface water sources,
these entities can largely maintain their present groundwater systems
(Berehe 2005, p. 65). All wholesale and retail water suppliers are
required to prepare and adopt drought contingency plans under TCEQ
rules (Title 30, Texas Administrative Code, Chapter 288) (Berehe 2005,
p. 64). However, these types of entities do not have authority to
control large-scale groundwater pumpage for private purposes that could
potentially impact a shared groundwater supply (Berehe 2005, p. 65).
Thus, groundwater levels may continue to decline due to private
pumping. The CUWCD in Bell County noted the effectiveness of their
groundwater management measures may be lessened if surrounding areas
(for example, Williamson County) are not likewise managing the shared
groundwater resource (Berehe 2005, p. 3). However, in comments on our
proposed rule, CUWCD stated that their ability to protect spring flow
is not impacted by pumping in Travis or Williamson Counties (Aaron
2012, CUWCD, pers. comm.).
Conclusion of Factor D
Surface water quality data collected by TCEQ and SWCA indicate that
water quality degradation is occurring within many of the surface
watersheds occupied by the Georgetown and Salado salamanders despite
the existence of State and local regulatory mechanisms to manage
stormwater and protect water quality (SWCA 2012, pp. 11-20; TCEQ 2012b,
pp. 646-736). Additionally, the threat to the Salado salamander from a
reduction in water quantity and the associated loss of spring flow has
not been completely alleviated despite efforts made in Bell County by
the CUWCD. No regulatory mechanisms are in place to manage groundwater
withdrawals in Williamson County. The human population in Williamson
and Bell Counties is projected to increase by 377 and 128 percent,
respectively, between 2010 and 2050. The associated increase in
urbanization is likely to result in continued impacts to water quality
absent additional regulatory mechanisms to prevent this from occurring.
The City of Georgetown's Edwards Aquifer Recharge Zone Water
Quality Ordinance, Water Quality Management Plan, and Adaptive
Management Plan will help to reduce some of the threats to groundwater
pollution that are typically associated with urbanized areas.
Additionally, for the Georgetown salamander, the Adaptive Management
Working Group is charged specifically with reviewing Georgetown
salamander monitoring data and new research over time and recommending
improvements to the ordinance that may be necessary to ensure that it
achieves its stated purposes. This Adaptive Management Working Group,
which includes representatives of the Service and TPWD, will also
review and make recommendations on the approval of any variances to the
ordinance to ensure that granting a variance will not be detrimental to
the preservation of the Georgetown salamander. While the beneficial
actions taken by the Georgetown City Council will reduce some of the
threats to the Georgetown salamander, there are additional threats that
have not been addressed by the ordinance. Therefore, we consider the
inadequacy of existing regulatory
[[Page 10284]]
mechanisms to be an ongoing threat to the Georgetown and Salado
salamanders now and in the future.
E. Other Natural or Manmade Factors Affecting Their Continued Existence
Small Population Size and Stochastic Events
The Georgetown and Salado salamanders may be susceptible to threats
associated with small population size and impacts from stochastic
events. The risk of extinction for any species is known to be highly
indirectly correlated with population size (O'Grady et al. 2004, pp.
516, 518; Pimm et al. 1988, pp. 774-775). In other words, the smaller
the population the greater the overall risk of extinction. Stochastic
events from either environmental factors (random events such as severe
weather) or demographic factors (random causes of births and deaths of
individuals) increase the risk of extinction of the Georgetown and
Salado salamanders because of their limited range and small population
sizes (Melbourne and Hastings 2008, p. 100). At small population
levels, the effects of demographic stochasticity alone greatly increase
the risk of local extinctions (Van Dyke 2008, p. 218).
Genetic factors play a large role in influencing the long-term
viability of small populations. Although it remains a complex field of
study, conservation genetics research has demonstrated that long-term
inbreeding depression (a pattern of reduced reproduction and survival
as a result of genetic relatedness) can occur within small populations
(Frankham 1995, p. 796; Latter et al. 1995, p. 294; Van Dyke 2008, pp.
155-156). Inbreeding depression contributes to further population
decline and reduced reproduction and survival in small populations, and
can contribute to a species' extinction (Van Dyke 2008, pp. 172-173).
Small populations may also suffer a loss of genetic diversity, reducing
the ability of these populations to evolve to changing environmental
conditions, such as climate change (Visser 2008, pp. 649-655; Traill et
al. 2010, pp. 29-30).
In addition, ecological factors such as Allee effects may manifest
at small population sizes, further increasing the risk of extinction
(Courchamp et al. 1999, p. 405). Allee effects are defined as a
positive relationship between any component of individual fitness (the
ability to survive and reproduce) and either numbers or density of
individuals of the same species (Stephens et al. 1999, p. 186). In
other words, an Allee effect refers to the phenomenon where
reproduction and survival rates of individuals increase with increasing
population density. For example, when a species has a small population,
it may be more difficult for individuals to encounter mates, reducing
their ability to produce offspring. Small population sizes can act
synergistically with ecological traits (such as being a habitat
specialist and having a limited distribution as in the Georgetown and
Salado salamanders) to greatly increase risk of extinction (Davies et
al. 2004, p. 270).
Current evidence from integrated work on population dynamics shows
that setting conservation targets at only a few hundred individuals
does not properly account for the synergistic impacts of multiple
threats facing a population (Traill et al. 2010, p. 32). As discussed
above, small populations are vulnerable to both stochastic demographic
factors and genetic factors. Studies across taxonomic groups have found
both the demographic and genetic constraints on populations require
sizes of at least 5,000 adult individuals to ensure long-term
persistence (Traill et al. 2010, p. 30). Populations below this number
are considered small and at increased risk of extinction. It is also
important to note that this general estimate does not take into account
species-specific ecological factors that may impact extinction risk,
such as Allee effects.
The population size of Georgetown and Salado salamanders is unknown
for most sites. Recent mark-recapture studies on the Georgetown
salamander estimated surface population sizes of 100 to 200 adult
salamanders at two sites thought to be of the highest quality for this
species (Twin Springs and Swinbank Springs, Pierce 2011a, p. 18).
Georgetown salamander populations are likely smaller at other, lower
quality sites. There are no population estimates available for any
Salado salamander sites, but recent surveys have indicated that Salado
salamanders are exceedingly rare at the four most impacted sites and
much more abundant at the three least impacted sites (Gluesenkamp
2011a, b, TPWD, pers. comm.). Because most of the sites occupied by the
Georgetown and Salado salamanders are not known to have many
individuals, any of the threats described above or stochastic events
that would not otherwise be considered a threat could extirpate
populations.
The highly restricted ranges of the Georgetown and Salado
salamanders and their entirely aquatic environmental habitat make them
extremely vulnerable to threats such as decreases in water quality and
quantity. The Georgetown salamander is only known from 15 surface and 2
cave sites. This species has not been observed in more than 20 years at
San Gabriel Spring and more than 10 years at Buford Hollow Spring,
despite several survey efforts to find it (Chippindale et al. 2000, p.
40, Pierce 2011b, c, Southwestern University, pers. comm.). We are
unaware of any population surveys in the last 10 years from a number of
sites (such as Cedar Breaks Hiking Trail, Shadow Canyon, and Bat Well).
Georgetown salamanders continue to be observed at the remaining 12
sites (Avant Spring, Swinbank Spring, Knight Spring, Twin Springs,
Cowan Creek Spring, Cedar Hollow Spring, Cobbs Spring/Cobbs Well, Garey
Ranch Spring, Hogg Hollow Spring, Hogg Hollow II Spring, Walnut Spring,
and Water Tank Cave) (Pierce 2011c, pers. comm.; Gluesenkamp 2011a,
TPWD, pers. comm.). Similarly, the Salado salamander has only been
found at seven spring sites, and two of these sites (Big Boiling and
Lil' Bubbly Springs) are very close together and are likely one
population. Due to their very limited distribution, these salamanders
are especially sensitive to stochastic incidences, such as severe and
unusual storm events (which can dramatically affect dissolved oxygen
levels), catastrophic contaminant spills, and leaks of harmful
substances.
Although rare, catastrophic events pose a significant threat to
small populations because they have the potential to eliminate all
individuals in a small group (Van Dyke 2008, p. 218). Although it may
be possible for Eurycea salamanders to travel through aquifer conduits
from one surface population to another, or that two individuals from
different populations could breed in subsurface habitat, there is no
direct evidence that they currently migrate from one surface population
to another on a regular basis. Although gene flow between populations
has been detected in other central Texas Eurycea salamander species
(TPWD 2012, pers. comm.), this does not necessarily mean that there is
current or routine dispersal between salamander populations that could
allow for recolonization of a site should the population be extirpated
by a catastrophic event (Gillespie 2012, University of Texas, pers.
comm.).
In conclusion, we do not consider small population sizes to be a
threat in and of itself to the Georgetown and Salado salamanders, but
their small population sizes make them more vulnerable to extinction
from other existing or potential threats, such as stochastic events.
Restricted ranges could negatively affect the Georgetown and Salado
salamanders in combination
[[Page 10285]]
with other threats (such as water quality or water quantity
degradation) and lead to the species being at a higher risk of
extinction. We consider the level of impacts from stochastic events to
be moderate for the Georgetown salamander, because this species has 17
populations over a broader range. On the other hand, recolonization
following a stochastic event is less likely for the Salado salamander
due to its more limited distribution and low numbers. Therefore, the
impact from a stochastic event for the Salado salamander is a
significant threat.
Ultraviolet Radiation
Increased levels of ultraviolet-B (UV-B) radiation, due to
depletion of the stratospheric ozone layers, may lead to declines in
amphibian populations (Blaustein and Kiesecker 2002, pp. 598-600). For
example, research has demonstrated that UV-B radiation causes
significant mortality and deformities in developing long-toed
salamanders (Ambystoma macrodactylum) (Blaustein et al. 1997, p.
13,735). Exposure to UV-B radiation reduces growth in clawed frogs
(Xenopus laevis) (Hatch and Burton, 1998, p. 1,783) and lowers hatching
success in Cascades frogs (Rana cascadae) and western toads (Bufo
boreas) (Kiesecker and Blaustein 1995, pp. 11,050-11,051). In lab
experiments with spotted salamanders, UV-B radiation diminished their
swimming ability (Bommarito et al. 2010, p. 1151). Additionally, UV-B
radiation may act synergistically (the total effect is greater than the
sum of the individual effects) with other factors (for example,
contaminants, pH, pathogens) to cause declines in amphibians (Alford
and Richards 1999, p. 141; see ``Synergistic and Additive Interactions
among Stressors'' below). Some researchers have indicated that future
increases in UV-B radiation will have significant detrimental impacts
on amphibians that are sensitive to this radiation (Blaustein and
Belden 2003, p. 95).
The effect of increased UV-B radiation on the Georgetown and Salado
salamanders is unknown. It is questionable whether the few cave
populations of the Georgetown salamander that are restricted entirely
to the subsurface are exposed to UV-B radiation. Surface populations
may receive some protection from UV-B radiation through shading from
trees or from hiding under rocks at some spring sites. Removal of
natural riparian vegetation and substrate alteration may put the
Georgetown and Salado salamanders at greater risk of UV-B exposure.
Because eggs are likely deposited underground (Bendik 2011b, COA, pers.
comm.), UV-B radiation may have no impact on the hatching success of
these species.
In conclusion, the effect of increased UV-B radiation has the
potential to cause deformities or developmental problems to
individuals, but we do not consider this to significantly contribute to
the risk of extinction for the Georgetown and Salado salamanders at
this time. However, UV-B radiation could negatively affect any of these
salamanders in combination with other threats (such as water quality or
water quantity degradation) and contribute to significant declines in
population sizes.
Synergistic and Additive Interactions Among Stressors
The interactions among multiple stressors (for example,
contaminants, UV-B radiation, pathogens, sedimentation, and drought)
may be contributing to amphibian population declines (Blaustein and
Kiesecker 2002, p. 598). Multiple stressors may act additively or
synergistically to have greater detrimental impacts on amphibians
compared to a single stressor alone. Kiesecker and Blaustein (1995, p.
11,051) found a synergistic effect between UV-B radiation and a
pathogen in Cascades frogs and western toads. Researchers demonstrated
that reduced pH levels and increased levels of UV-B radiation
independently had no effect on leopard frog (Rana pipiens) larvae;
however, when combined, these two caused significant mortality (Long et
al. 1995, p. 1,302). Additionally, researchers demonstrated that UV-B
radiation increases the toxicity of PAHs, which can cause mortality and
deformities on developing amphibians (Hatch and Burton 1998, pp. 1,780-
1,783). Beattie et al. (1992, p. 566) demonstrated that aluminum
becomes toxic to amphibians at low pH levels. Also, disease outbreaks
may occur only when there are contaminants or other stressors in the
environment that reduce immunity (Alford and Richards 1999, p. 141).
For example, Christin et al. (2003, pp. 1,129-1,132) demonstrated that
mixtures of pesticides reduced the immunity to parasitic infections in
leopard frogs. Finally, the interaction of different stressors may
interfere with a salamander species' ability to adapt to a stressor.
Miller et al. (2007, pp. 82-83) found that although southern two-lined
salamander larvae could adapt to low-flow conditions by migrating down
into the water table, they were unable to perform this behavior when
the interstitial spaces between rocks were filled with sediment.
Currently, the synergistic effect between multiple stressors on the
Georgetown and Salado salamanders is not fully known. Furthermore,
different species of amphibians differ in their reactions to stressors
and combinations of stressors (Kiesecker and Blaustein 1995, p. 11,051;
Relyea et al. 2009, pp. 367-368; Rohr et al. 2003, pp. 2,387-2,390).
Studies that examine the effects of interactions among multiple
stressors on the Georgetown and Salado salamanders are lacking.
However, based on the number of examples in other amphibians, the
possibility of synergistic effects on the salamanders cannot be
discounted.
Conclusion of Factor E
The effect of increased UV-B radiation is an unstudied stressor to
the Georgetown and Salado salamanders that has the potential to cause
deformities or development problems. There is no evidence that the
salamander species' exposure to UV-B radiation is increasing or
spreading. In addition, small population sizes at most of the sites for
the Georgetown and Salado salamanders increases the risk of local
extirpation events. We do not consider small population sizes to be a
threat in and of itself to the Georgetown and Salado salamanders, but
their small population sizes make them more vulnerable to extinction
from other existing or potential threats, such as stochastic events.
Thus, we consider the level of impacts from stochastic events to be
high for the Georgetown and Salado salamanders due to their limited
distributions and low number of populations. Finally, the synergistic
and additive interactions among multiple stressors (contaminants, UV-B
radiation, pathogens) may impact Georgetown and Salado salamanders
based on studies of other amphibians.
Conservation Efforts To Reduce Other Natural or Manmade Factors
Affecting Its Continued Existence
We have no information on any conservation efforts currently
underway to reduce the effects of UV-B radiation, small population
sizes, stochastic events, or the synergistic and additive interactions
among multiple stressors on the Georgetown and Salado salamanders.
Cumulative Impacts
Cumulative Effects From Factors A Through E
Some of the threats discussed in this finding could work in concert
with one another to cumulatively create situations that impact the
Georgetown
[[Page 10286]]
and Salado salamanders. Some threats to these species may seem to be of
low significance by themselves, but when you consider other threats
that are occurring at each site, such as small population sizes, the
risk of extirpation is increased. Furthermore, we have no direct
evidence that salamanders currently migrate from one population to
another on a regular basis, and many of the populations are isolated in
a way that makes re-colonization of extirpated sites very unlikely.
Cumulatively, as threats to the species increase over time in tandem
with increasing urbanization within the surface watersheds of these
species, more and more populations will be lost, which will increase
the species' risk of extinction.
Overall Threats Summary
The primary threat to the Georgetown and Salado salamanders is the
present or future destruction, modification, or curtailment of their
habitat or range (Factor A) in the form of reduced water quality and
quantity and disturbance of spring sites (surface habitat). Reductions
in water quality will occur primarily as a result of urbanization,
which increases the amount of impervious cover in the watershed and
exposes the salamanders to more hazardous material sources. Impervious
cover increases storm flow, erosion, and sedimentation. Impervious
cover also changes natural flow regimes within watersheds and increases
the transport of contaminants common in urban environments, such as
oils, metals, fertilizers, and pesticides. Expanding urbanization
results in an increase of these contaminants within the watershed,
which degrades water quality at salamander spring sites. Additionally,
urbanization increases nutrient loads at spring sites, which can lead
to decreases in dissolved oxygen levels. Construction activities
associated with urbanization are a threat to both water quality and
quantity because they can increase sedimentation and exposure to
contaminants, as well as dewater springs by intercepting aquifer
conduits.
Various other threats to habitat exist for the Georgetown and
Salado salamanders as well. Drought, which may be compounded by the
effects of global climate change, also degrades water quantity and
reduces available habitat for the salamanders. Water quantity can also
be reduced by groundwater pumping and decreases in baseflow due to
increases in impervious cover. Flood events contribute to the
salamanders' risks of extinction by degrading water quality through
increased contaminants levels and sedimentation, which may damage or
alter substrates, and by removing rocky substrates or washing
salamanders out of suitable habitat. Impoundments are also a threat to
these species' habitat because of their tendency to alter the stream
substrate and increase predacious fish abundance. Feral hogs and
livestock are threats because they can physically alter the
salamander's surface habitat and increase nutrients. Additionally,
catastrophic spills and leaks remain a threat for many salamander
locations due to the abundance of point-sources and history of past
spill events. All of these threats are projected to increase in the
future, as the human population and development increases within
watersheds that provide habitat for these salamanders. The human
population is projected to increase by 377 percent in the range of the
Georgetown salamander and by 128 percent in the range of the Salado
salamander by 2050. Some of these threats are moderated, in part, by
ongoing conservation efforts, preserves, and other programs in place to
protect land from the effects of urbanization and to gather water
quality data that would be helpful in designing conservation strategies
for the salamander species. Overall, we consider the combined threats
of Factor A to be ongoing and with a high degree of impact to the
Georgetown and Salado salamanders and their habitats in the future.
Another factor we considered is Factor D, the inadequacy of
existing regulatory mechanisms. Surface water quality data collected by
TCEQ indicates that water quality degradation is occurring within many
of the surface watersheds occupied by the Georgetown and Salado
salamanders despite the existence of numerous state and local
regulatory mechanisms to manage stormwater and protect water quality.
Additionally, the threat to the Salado salamander from a reduction in
water quantity and the associated loss of spring flow has not been
completely alleviated through the management of groundwater in Bell
County by the CUWCD. Groundwater resources are not holistically managed
in Williamson County to protect the aquifer from depletion from private
pumping. Human population growth and urbanization in Williamson and
Bell Counties is projected to continue into the future as well as the
associated impacts to water quality and quantity (see Factor A
discussion above). However, the Edwards Aquifer Recharge Zone Water
Quality Ordinance approved by the Georgetown City Council in December
2013 is expected to reduce some of the threats to the Georgetown
salamander from water quality degradation and direct impacts to surface
habitat. Existing regulations are not providing adequate protection for
the Georgetown and Salado salamanders and their habitats. Therefore, we
consider the existing regulatory mechanisms inadequate to protect the
Georgetown and Salado salamander now and in the future.
Under Factor E, we identified several stressors that could
negatively impact any of the Georgetown and Salado salamanders,
including the increased risk of local extirpation events due to small
population sizes and stochastic events, UV-B radiation, and the
synergistic and additive effects of multiple stressors. Although none
of these stressors rose to the level of being considered a threat by
itself, small population sizes and restricted ranges make the
Georgetown and Salado salamanders more vulnerable to extirpation from
other existing or potential threats, such as stochastic events. Thus,
we consider the level of impacts from stochastic events to be high for
the Georgetown and Salado salamanders due to their low number of
populations and limited distributions.
Determination
Standard for Review
Section 4 of the Act, and its implementing regulations at 50 CFR
part 424, set forth the procedures for adding species to the Federal
Lists of Endangered and Threatened Wildlife and Plants. Under section
4(b)(1)(a), the Secretary is to make endangered or threatened
determinations required by subsection 4(a)(1) solely on the basis of
the best scientific and commercial data available after conducting a
review of the status of the species and after taking into account
conservation efforts by States or foreign nations. The standards for
determining whether a species is endangered or threatened are provided
in section 3 of the Act. An endangered species is any species that is
``in danger of extinction throughout all or a significant portion of
its range.'' A threatened species is any species that is ``likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range.'' Per section 4(a)(1) of the
Act, in reviewing the status of the species to determine if it meets
the definitions of endangered or threatened, we determine whether any
species is an endangered species or a threatened species because of any
of the following five factors: (A) The present or threatened
destruction,
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modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; and (E) other natural or manmade
factors affecting its continued existence.
We evaluated whether the Georgetown and Salado salamanders are in
danger of extinction now (that is, an endangered species) or are likely
to become in danger of extinction in the foreseeable future (that is, a
threatened species). The foreseeable future refers to the extent to
which the Secretary can reasonably rely on predictions about the future
in making determinations about the future conservation status of the
species. A key statutory difference between a threatened species and an
endangered species is the timing of when a species may be in danger of
extinction, either now (endangered species) or in the foreseeable
future (threatened species).
Listing Status Determination for the Georgetown Salamander
In the proposed rule (77 FR 50768, August 22, 2012), the Georgetown
salamander species was proposed as endangered, rather than threatened,
because at that time, we determined the threats to be imminent, and
their potential impacts to the species would be catastrophic given the
very limited range of the species. For this final determination, we
took into account data that were made available after the proposed rule
published, information provided by commenters on the proposed rule, and
further discussions within the Service to determine whether the
Georgetown salamander should be classified as endangered or threatened.
Based on our review of the best available scientific and commercial
information, we conclude that the Georgetown salamander is likely to
become in danger of extinction in the foreseeable future throughout all
of its range and, therefore, meets the definition of a threatened
species. This finding, explained below, is based on our conclusions
that some habitat supporting populations of the species have begun to
experience impacts from threats, and threats are expected to increase
in the future. As the threats increase, we expect Georgetown salamander
populations to decline and be extirpated, reducing the overall
representation and redundancy across the species range and increasing
the species risk of extinction. We find the Georgetown salamander will
be at an elevated risk of extinction in the future. While beneficial
actions taken by the Georgetown City Council are expected to reduce the
threats to the Georgetown salamander, additional threats have not been
addressed by their recent water quality ordinance. We, therefore, find
that the Georgetown salamander warrants a threatened species listing
status determination. Elsewhere in today's Federal Register, we propose
special regulations for the Georgetown salamander under section 4(d) of
the Act. We invite public comment on that proposed special rule.
There is a limited amount of data on the current status of most
Georgetown salamander populations and how these populations respond to
stressors. Of the 17 known Georgetown salamander populations, only 3
have been regularly monitored since 2008, and we only have population
estimates for 2 of those sites. In addition, no studies have used
controlled experiments to understand how environmental changes might
affect Georgetown salamander individuals. To deal with this uncertainty
and evaluate threats to the Georgetown salamander that are occurring
now or in the future, we used information on substitute species, which
is an accepted practice in aquatic ecotoxicology and conservation
biology (Caro et al. 2005, p. 1,823; Wenger 2008, p. 1,565). In
instances where information was not available for the Georgetown
salamander specifically, we have provided references for studies
conducted on similarly related species, such as the Jollyville Plateau
salamander and Barton Springs salamander, which occur within the
central Texas area, and other salamander species that occur in other
parts of the United States. We concluded that these were appropriate
comparisons to make based on the following similarities between the
species: (1) A clear systematic (evolutionary) relationship (for
example, members of the Family Plethodontidae); (2) shared life-history
attributes (for example, the lack of metamorphosis into a terrestrial
form); (3) similar morphology and physiology (for example, the lack of
lungs for respiration and sensitivity to environmental conditions); and
(4) similar habitat and ecological requirements (for example,
dependence on aquatic habitat in or near springs with a rocky or gravel
substrate).
Present and future degradation of habitat (Factor A) is the primary
threat to the Georgetown salamander. This threat primarily occurs in
the form of reduced water quality from introduced and concentrated
contaminants, increased sedimentation, and altered stream flow regimes.
Reduced water quality from increased conductivity, PAHs, pesticides,
and nutrients have all been shown to have detrimental impacts on
salamander density, growth, and behavior (Marco et al. 1999, p. 2,837;
Albers 2003, p. 352; Rohr et al. 2003, p. 2,391; Bowles et al. 2006,
pp. 117-118; O'Donnell et al. 2006, p. 37; Reylea 2009, p. 370;
Sparling et al. 2009, p. 28; Bommarito et al. 2010, pp. 1,151-1,152).
Sedimentation causes the amount of available foraging habitat and
protective cover for salamanders to be reduced (Welsh and Ollivier
1998, p. 1,128), reducing salamander abundance (Turner 2003, p. 24;
O'Donnell et al. 2006, p. 34). Sharp declines and increases in stream
flow have also been shown to reduce salamander abundance (Petranka and
Sih 1986, p. 732; Sih et al. 1992, p. 1,429; Baumgartner et al. 1999,
p. 36; Miller et al. 2007, pp. 82-83; Price et al. 2012b, p. 319). In
the absence of species-specific information, we conclude that
Georgetown salamanders respond negatively to these stressors because
aquatic invertebrates (the prey base of the Georgetown salamander) and
several species of closely related stream salamanders have demonstrated
direct and indirect negative responses to these stressors.
Reduced water quality, increased sedimentation, and altered flow
regimes are primarily the result of human population growth and
subsequent urbanization within the watersheds and recharge and
contributing zones of the groundwater supporting spring and cave sites.
Urbanization in the range of the Georgetown salamander is currently at
relatively low levels. However, based on our current knowledge of the
Georgetown salamander and observations made on the impacts of
urbanization on other closely related species of aquatic salamanders,
urbanization at current levels is likely affecting both surface and
subsurface habitat. Based on our analysis of impervious cover (which we
use as a proxy for urbanization) throughout the range of the Georgetown
salamander, 10 of 12 surface watersheds known to be occupied by
Georgetown salamanders in 2006 had levels of impervious cover that are
likely causing habitat degradation now. Although we do not have long-
term survey data on Georgetown salamander populations, the best
available information indicates that habitat degradation from
urbanization is causing declines in Georgetown salamander populations
throughout most of the species' range now or will cause population
declines in the future, putting these populations at an elevated risk
of extirpation.
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Further degradation of the Georgetown salamander's habitat is
likely to continue into the foreseeable future based on the current
projected increases in urbanization in the region. Substantial human
population growth is ongoing within this species' range, indicating
that the urbanization and its effects on Georgetown salamander habitat
will likely increase in the future. The human population within the
range of the Georgetown salamander is expected to increase by 375
percent from the year 2000 to 2033 (City of Georgetown 2008, p. 3.5).
Hazardous materials that could be spilled or leaked resulting in
the contamination of both surface and groundwater resources add to the
additional threats affecting the Georgetown salamander. For example, a
number of point-sources of pollutants exist within the Georgetown
salamander's range, including fuel tankers, fuel storage tanks,
wastewater lines, and chlorinated drinking water lines, and some of
these sources have contaminated groundwater in the past (Mace et al.
1997, p. 32; City of Georgetown 2008, p. 3.37; McHenry et al. 2011, p.
1). It is unknown what effect these past spills have had on Georgetown
salamander populations thus far. As development around Georgetown
increases, the number of point-sources will increase within the range
of the Georgetown salamander, subsequently increasing the likelihood of
a hazardous materials spill or leak. However, the City of Georgetown's
ordinance to protect water quality will help reduce the risk of a
significant hazardous materials spill impacting surface stream
drainages of the Georgetown salamander by requiring roadways that have
a capacity of 25,000 vehicles per day to provide for spill containment
as described in the TCEQ's Optional Enhanced Measures.
In addition, construction activities resulting from urban
development or rock quarry mining activities may negatively impact both
water quality and quantity because they can increase sedimentation and
dewater springs by intercepting aquifer conduits. There are currently
five Georgetown salamander sites that are located within 1 mile (1.6
km) of active rock quarries within Williamson County, Texas, which may
impact the species and its habitat, and which could result in the
destruction of spring sites, collapse of karst caverns, degradation of
water quality, and reduction of water quantity (Ekmekci 1990, p. 4). In
2004, elevated levels of perchlorate (a chemical used in producing
quarry explosives) were detected in multiple springs within Williamson
County, indicating that quarry activities were having an impact on
local water quality (Berehe 2005, p. 44). At this time, we are not
aware of any studies that have examined sediment loading due to
construction activities within the watersheds of Georgetown salamander
habitat. While the City of Georgetown's new water quality ordinance
will reduce construction-related sediment loading, it will not remove
all such loading, and given that construction-related sediment loading
has been shown to impact other salamander species (Turner 2003, p. 24;
O'Donnell et al. 2006, p. 34), sediment loading is likely to occur
within the rapidly developing range of the Georgetown salamander. Thus,
we expect that effects from construction activities will increase as
urbanization increases within the range of the Georgetown salamander.
The habitat of Georgetown salamanders is sensitive to direct
physical habitat modification, such as those resulting from human
recreational activities, impoundments, feral hogs, and livestock.
Present disturbance of Georgetown salamander habitat has been
attributed to direct human modification of spring outlets (TPWD 2011a,
p. 9), feral hog activity (Booker 2011, pers. comm.), and livestock
activity (White 2011, SWCA, pers. comm.).
The effects of present and future climate change could also affect
water quantity and spring flow for the Georgetown salamander. Climate
change could compound the threat of decreased water quantity at
salamander spring sites by decreasing precipitation, increasing
evaporation, increasing groundwater pumping demands, and increasing the
likelihood of extreme drought events. Climate change could cause spring
sites with small amounts of discharge to go dry and no longer support
salamanders, reducing the overall redundancy and representation for the
species. For example, at least two Georgetown salamander sites (Cobb
and San Gabriel Springs) are known to lose surface flow for periods of
time (Booker 2011, p. 1; Breen and Faucette 2013, p. 1). Climate change
is causing extreme droughts to become much more probable than they were
40 to 50 years ago (Rupp et al. 2012, pp. 1,053-1,054). Therefore,
climate change is an ongoing threat to this species that could add to
the likelihood of the Georgetown salamander becoming an endangered
species within the foreseeable future.
Although there are several regulations in place (Factor D) that
benefit the Georgetown salamander, none have proven adequate to protect
this species' habitat from degradation. Data indicate that some water
quality degradation in the range of the Georgetown salamander has
occurred and continues to occur despite relatively low impervious cover
and the existence of state and local regulatory mechanisms in place to
protect water quality (SWCA 2012, pp. 11-20; TCEQ 2012b, pp. 646-736).
In addition, Williamson County does not currently have a groundwater
conservation district that can manage groundwater resources countywide
and prevent groundwater levels from declining from private pumping.
Existing regulations have not prevented the disturbance of surface
habitat that has occurred at several sites. The City of Georgetown's
Edwards Aquifer Recharge Zone Water Quality Ordinance, Water Quality
Management Plan, and Adaptive Management Plan, approved in December
2013, will help to reduce some of the threats from water quality
degradation and direct impacts to surface habitat that are typically
associated with urbanized areas. However, these mechanisms are not
adequate to protect this species and its habitat now, nor do we
anticipate them to sufficiently protect this species and its habitat in
the future.
Other natural or manmade factors (Factor E) affecting all
Georgetown salamander populations include UV-B radiation, small
population sizes, stochastic events (such as floods or droughts), and
synergistic and additive interactions among the stressors mentioned
above. For example, the only mark-recapture studies on the Georgetown
salamander estimated surface population sizes of 100 to 200 adult
salamanders at 2 sites thought to be of the highest quality for this
species (Twin Springs and Swinbank Springs, Pierce 2011a, p. 18).
Georgetown salamander populations are likely smaller at other, lower
quality sites. In fact, this species has not been observed in more than
10 years at two locations (San Gabriel Spring and Buford Hollow
Spring), despite several survey efforts to find it (Pierce 2011b, c,
Southwestern University, pers. comm.). Factors such as small population
size, especially in combination with the threats summarized above, make
Georgetown salamander populations less resilient and more vulnerable to
population extirpations in the foreseeable future.
Because of the fact-specific nature of listing determinations,
there is no single metric for determining if a species is ``in danger
of extinction'' now. In the case of the Georgetown salamander, the best
available information indicates that habitat degradation will result in
significant impacts on salamander
[[Page 10289]]
populations. The threat of urbanization indicates that most of the
Georgetown salamander populations are currently at an elevated risk of
extirpation, or will be at an elevated risk in the future. These
impacts are expected to increase in severity and scope as urbanization
within the range of the species increases. Also, the combined result of
increased impacts to habitat quality and inadequate regulatory
mechanisms leads us to the conclusion that Georgetown salamanders will
likely be in danger of extinction within the foreseeable future. As
Georgetown salamander populations become more degraded, isolated, or
extirpated by urbanization, the species will lose resiliency and be at
an elevated risk from climate change impacts, small population sizes,
and catastrophic events, such as drought, floods, and hazardous
material spills. These events will affect all known extant populations,
putting the Georgetown salamander at a high risk of extinction.
Therefore, because the resiliency of populations is expected to
decrease in the foreseeable future, the Georgetown salamander will be
in danger of extinction throughout all of its range in the foreseeable
future, and appropriately meets the definition of a threatened species
(that is, in danger of extinction in the foreseeable future).
Under the Act and our implementing regulations, a species may
warrant listing if it is endangered or threatened throughout all or a
significant portion of its range. The threats to the survival of this
species occur throughout its range and are not restricted to any
particular significant portion of its range. Accordingly, our
assessments and determinations apply to this species throughout its
entire range.
In conclusion, as described above, the Georgetown salamander is
subject to significant current and ongoing threats now and will be
subject to more severe threats in the future. After a review of the
best available scientific information as it relates to the status of
the species and the five listing factors, we find the Georgetown
salamander is not currently in danger of extinction, but will be in
danger of extinction in the future. Therefore, on the basis of the best
available scientific and commercial information, we list the Georgetown
salamander as a threatened species in accordance with section 3(6) of
the Act. We find that an endangered species status is not appropriate
for the Georgetown salamander because the species is not in danger of
extinction at this time. While some threats to the Georgetown
salamander are occurring now, the impacts from these threats are not
yet at a level that puts this species in danger of extinction now.
However, with future urbanization and the added effects of climate
change, we expect habitat degradation and Georgetown salamander count
declines to continue into the future to the point where the species
will then be in danger of extinction.
Listing Status Determination for the Salado Salamander
In the proposed rule (77 FR 50768, August 22, 2012), the Salado
salamander species was proposed as endangered, rather than threatened,
because at that time, we determined the threats to be imminent, and
their potential impacts to the species would be catastrophic given the
very limited range of the species. For this final determination, we
took into account data that were made available after the proposed rule
published, information provided by commenters on the proposed rule, and
further discussions within the Service to determine whether the Salado
salamander should be classified as endangered or threatened. Based on
our review of the best available scientific and commercial information,
we conclude that the Salado salamander is likely to become in danger of
extinction in the foreseeable future throughout all of its range and,
therefore, meets the definition of a threatened species. This finding,
explained below, is based on our conclusions that few (seven) Salado
salamander sites exist (some of these sites are close to each other and
likely part of the same population), some populations have begun to
experience impacts from threats to its habitat, and these threats are
expected to increase in the future. As the threats increase, we expect
Salado salamander populations to decline and be extirpated, reducing
the overall representation and redundancy across the species range and
increasing the species risk of extinction. We find the Salado
salamander will be at an elevated risk of extinction in the future. We,
therefore, find that the Salado salamander warrants a threatened
species listing status determination.
There is a limited amount of data on Salado salamander populations
and how these populations respond to stressors. There are no population
estimates for any of the seven known Salado salamander populations, and
salamanders are very rarely seen at four of the seven sites. In
addition, no studies have used controlled experiments to understand how
environmental changes might affect Salado salamander individuals. To
deal with this uncertainty and evaluate threats to the Salado
salamander that are occurring now or in the future, we used information
on substitute species, which is an accepted practice in aquatic
ecotoxicology and conservation biology (Caro et al. 2005, p. 1823;
Wenger 2008, p. 1,565). In instances where information was not
available for the Salado salamander specifically, we have provided
references for studies conducted on similarly related species, such as
the Jollyville Plateau salamander and Barton Springs salamander, which
occur within the central Texas area, and other salamander species that
occur in other parts of the United States. We concluded that these were
appropriate comparisons to make based on the following similarities
between the species: (1) a clear systematic (evolutionary) relationship
(for example, members of the Family Plethodontidae); (2) shared life
history attributes (for example, the lack of metamorphosis into a
terrestrial form); (3) similar morphology and physiology (for example,
the lack of lungs for respiration and sensitivity to environmental
conditions); and (4) similar habitat and ecological requirements (for
example, dependence on aquatic habitat in or near springs with a rocky
or gravel substrate).
Present and future degradation of habitat (Factor A) is the primary
threat to the Salado salamander. This threat primarily occurs in the
form of reduced water quality from introduced and concentrated
contaminants, increased sedimentation, and altered stream flow regimes.
Reduced water quality from increased conductivity, PAHs, pesticides,
and nutrients have all been shown to have detrimental impacts on
salamander density, growth, and behavior (Marco et al. 1999, p. 2,837;
Albers 2003, p. 352; Rohr et al. 2003, p. 2,391; Bowles et al. 2006,
pp. 117-118; O'Donnell et al. 2006, p. 37; Reylea 2009, p. 370;
Sparling et al. 2009, p. 28; Bommarito et al. 2010, pp. 1,151-1,152).
Sedimentation causes the amount of available foraging habitat and
protective cover for salamanders to be reduced (Welsh and Ollivier
1998, p. 1,128), reducing salamander abundance (Turner 2003, p. 24;
O'Donnell et al. 2006, p. 34). Sharp declines and increases in stream
flow have also been shown to reduce salamander abundance (Petranka and
Sih 1986, p. 732; Sih et al. 1992, p. 1,429; Baumgartner et al. 1999,
p. 36; Miller et al. 2007, pp. 82-83; Price et al. 2012b, p. 319). In
the absence of species-specific information, we conclude that Salado
salamanders respond negatively to these stressors
[[Page 10290]]
because aquatic invertebrates (the prey base of the Salado salamander)
and several species of closely related stream salamanders have
demonstrated direct and indirect negative responses to these stressors.
Reduced water quality, increased sedimentation, and altered flow
regimes are primarily the result of human population growth and
subsequent urbanization within the watersheds and recharge and
contributing zones of the groundwater supporting spring and cave sites.
Urbanization in the range of the Salado salamander is currently at
relatively low levels. However, based on our current knowledge of the
Salado salamander and observations made on the impacts of urbanization
on other closely related species of aquatic salamanders, urbanization
is likely affecting both surface and subsurface habitat and is likely
having impacts on Salado salamander populations. Based on our analysis
of impervious cover (which we use as a proxy for urbanization)
throughout the range of the Salado salamander, five of the six surface
watersheds occupied by Salado salamanders had levels of impervious
cover in 2006 that are likely causing habitat degradation. Although we
do not have long-term survey data on Salado salamander populations,
recent surveys have indicated that Salado salamanders are exceedingly
rare at the three most impacted sites (no salamanders were found during
surveys conducted in 2012; Hibbitts 2013, p. 2) and more abundant at
the three least impacted sites (Gluesenkamp 2011a, b, TPWD, pers.
comm.). The best available information indicates that habitat
degradation from urbanization or physical disturbance is causing
declines in Salado salamander populations throughout most of the
species' range now, or will cause population declines in the future,
putting these populations at an elevated risk of extirpation.
Further degradation of the Salado salamander's habitat is expected
to continue into the future, primarily as a result of an increase in
urbanization. Substantial human population growth is ongoing within
this species' range, indicating that the urbanization and its effects
on Salado salamander habitat will increase in the future. The Texas
State Data Center (2012, p. 353) has reported a population increase of
128 percent for Bell County, Texas, from the year 2010 to 2050. Because
subsurface flow into some Salado salamander sites may originate in
Williamson County to the southwest, human population growth in
Williamson County also could have increasing negative impacts on Salado
salamander habitat. The Texas State Data Center estimates a 377 percent
increase in human population in Williamson County from 2010 to 2050.
Adding to the likelihood of the Salado salamander becoming
endangered in the future is the risk from hazardous materials that
could be spilled or leaked, potentially resulting in the contamination
of both surface and groundwater resources. Three of the seven Salado
salamander sites are located less than 0.25 mi (0.40 km) downstream of
Interstate Highway 35 and may be particularly vulnerable to spills due
to their proximity to this major transportation corridor. Should a
hazardous materials spill occur at the Interstate Highway 35 bridge
that crosses at Salado Creek, this species could be at risk from
contaminants entering the water flowing into its surface habitat
downstream. In addition, multiple petroleum leaks from underground
storage tanks have occurred near Salado salamander sites in the past
(Price et al. 1999, p. 10). Because no follow-up studies were
conducted, we have no information to indicate what effect these spills
had on the species or its habitat. A significant hazardous materials
spill within stream drainages of the Salado salamander has the
potential to threaten the long-term survival and sustainability of
multiple populations, and we expect the risk of spills will increase in
the future as urbanization increases.
In addition, construction activities resulting from urban
development or rock quarry mining activities may negatively impact both
water quality and quantity because they can increase sedimentation and
dewater springs by intercepting aquifer conduits. There is currently an
active rock quarry located within 1.25 mi (2.0 km) of three Salado
salamander sites within Bell County, Texas, which may impact the
species and its habitat, and which could result in the collapse of
karst caverns, degradation of water quality, and reduction of water
quantity (Ekmekci 1990, p. 4). At this time, we are not aware of any
studies that have examined sediment loading due to construction
activities within the watersheds of Salado salamander habitat. However,
given that construction-related sediment loading has been shown to
impact other salamander species (Turner 2003, p. 24; O'Donnell et al.
2006, p. 34) and is likely to occur within the developing range of the
Salado salamander, we expect that effects from construction activities
will increase as urbanization increases within the range of the Salado
salamander.
The habitat of Salado salamanders is sensitive to direct physical
habitat modification, such as those resulting from human recreational
activities, impoundments, feral hogs, and livestock. Destruction of
Salado salamander habitat has been attributed to direct human
modification, including heavy machinery use, outflow channel
reconstruction, substrate alteration, and impoundments (Service 2010,
p. 6; Gluesenkamp 2011a, c, pers. comm.). One of the seven Salado
salamander sites is unfenced and vulnerable to access and damage from
livestock and feral hogs.
The effects of present and future climate change could also affect
water quantity and spring flow for the Salado salamander. Climate
change will likely compound the threat of decreased water quantity at
salamander spring sites by decreasing precipitation, increasing
evaporation, increasing groundwater pumping demands, and increasing the
likelihood of extreme drought events. Climate change could cause spring
sites with small amounts of discharge to go dry and no longer support
salamanders, reducing the overall redundancy and representation for the
species. For example, at least two Salado salamander sites (Robertson
Spring and Lil' Bubbly Spring) are known to lose surface flow for
periods of time (Gluesenkamp 2011a, pers. comm.; Breen and Faucette
2013, p. 1). Climate change is currently causing extreme droughts to
become much more probable than they were 40 to 50 years ago (Rupp et
al. 2012, pp. 1,053-1,054). Therefore, climate change is an ongoing
threat to this species and will add to the likelihood of the Salado
salamander becoming an endangered species within the foreseeable
future.
Although there are several regulations in place (Factor D) that
benefit the Salado salamander, none have proven adequate to protect
this species' habitat from degradation. Data indicate that some water
quality degradation in the range of the Salado salamander has occurred
and continues to occur despite relatively low impervious cover and the
existence of state and local regulatory mechanisms in place to protect
water quality (TCEQ 2012b, pp. 646-736). In addition, although Bell
County does have a groundwater conservation district that can manage
groundwater resources countywide, this management has not prevented
Salado salamander spring sites from going dry during droughts (TPWD
2011a, p. 5; Aaron 2013, CUWCD, pers. comm.; Breen and Faucette 2013,
pers. comm.). Finally, no regulations have prevented the disturbance of
the physical surface habitat that has occurred at three sites
[[Page 10291]]
within the Village of Salado. Therefore, the existing regulatory
mechanisms are not adequate to protect this species and its habitat
now, nor do we anticipate them to sufficiently protect this species in
the future.
Other natural or manmade factors (Factor E) affecting all Salado
salamander populations include UV-B radiation, small population sizes,
stochastic events (such as floods or droughts), and synergistic and
additive interactions among the stressors mentioned above. Because of
how rare Salado salamanders are at most sites (Gluesenkamp 2011a, b,
TPWD, pers. comm.; TPWD 2011a, pp. 1-3), we assume that population
sizes are very small. Factors such as small population size, in
combination with the threats summarized above, make Salado salamander
populations less resilient and more vulnerable to population
extirpations in the foreseeable future.
Because of the fact-specific nature of listing determinations,
there is no single metric for determining if a species is ``in danger
of extinction'' now. In the case of the Salado salamander, the best
available information indicates that habitat degradation will result in
significant impacts on salamander populations. The threat of
urbanization indicates that most of the Salado salamander populations
are currently at an elevated risk of extirpation, or will be at an
elevated risk in the future. These impacts are expected to increase in
severity and scope as urbanization within the range of the species
increases. Also, the combined result of increased impacts to habitat
quality and inadequate regulatory mechanisms leads us to the conclusion
that Salado salamanders will likely be in danger of extinction within
the foreseeable future. As Salado salamander populations become more
degraded, isolated, or extirpated by urbanization, the species will
lose resiliency and be at an elevated risk from climate change impacts,
small population sizes, and catastrophic events (for example, drought,
floods, hazardous material spills). These events will affect all known
extant populations, putting the Salado salamander at a high risk of
extinction. Therefore, because the resiliency of populations is
expected to decrease in the foreseeable future, the Salado salamander
will be danger of extinction throughout all of its range in the future,
and it appropriately meets the definition of a threatened species (that
is, in danger of extinction in the foreseeable future).
Under the Act and our implementing regulations, a species may
warrant listing if it is endangered or threatened throughout all or a
significant portion of its range. The threats to the survival of this
species occur throughout its range and are not restricted to any
particular significant portion of its range. Accordingly, our
assessments and determinations apply to this species throughout its
entire range.
In conclusion, the Salado salamander is subject to significant
current and ongoing threats now and will be subject to more severe
threats in the future. After a review of the best available scientific
information as it relates to the status of the species and the five
listing factors, we find the Salado salamander is not in danger of
extinction now, but will be in danger of extinction in the foreseeable
future. Therefore, on the basis of the best available scientific and
commercial information, we list the Salado salamander as a threatened
species, in accordance with section 3(6) of the Act. We find that an
endangered species status is not appropriate for the Salado salamander
because the species is not in danger of extinction now. While some
threats to the Salado salamander are occurring now, the impacts from
these threats are not yet at a level that puts this species in danger
of extinction at this time. However, with future urbanization and the
added effects of climate change, we expect habitat degradation and
Salado salamander count declines to continue into the foreseeable
future to the point where the species will then be in danger of
extinction.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened species under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness and
conservation by Federal, state, tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
states and requires that recovery actions be carried out for all listed
species. The protection required by Federal agencies and the
prohibitions against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
decline in the species' status by addressing the threats to its
survival and recovery. The goal of this process is to restore listed
species to a point where they are secure, self-sustaining, and
functioning components of their ecosystems.
Recovery planning includes the development of a recovery outline
shortly after a species is listed and preparation of a draft and final
recovery plan. The recovery outline guides the immediate implementation
of urgent recovery actions and describes the process to be used to
develop a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available. The recovery plan identifies site-
specific management actions that set a trigger for review of the five
factors that control whether a species remains endangered or may be
downlisted or delisted, and methods for monitoring recovery progress.
Recovery plans also establish a framework for agencies to coordinate
their recovery efforts and provide estimates of the cost of
implementing recovery tasks. Recovery teams (comprising species
experts, Federal and state agencies, non-governmental organizations,
and stakeholders) are often established to develop recovery plans. When
completed, the recovery outline, draft recovery plan, and the final
recovery plan will be available on our Web site (http://www.fws.gov/endangered), or from our Austin Ecological Services Field Office (see
FOR FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, states, tribes, non-governmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (for example, restoration of native vegetation), research,
captive propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, state, tribal, and other
lands.
Once these species are listed, funding for recovery actions will be
available from a variety of sources, including Federal budgets, state
programs, and cost-share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. In addition,
pursuant to section 6 of the
[[Page 10292]]
Act, the State of Texas will be eligible for Federal funds to implement
management actions that promote the protection or recovery of the
Georgetown and Salado salamanders. Information on our grant programs
that are available to aid species recovery can be found at: http://www.fws.gov/grants.
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or listed as
endangered or threatened and with respect to its critical habitat, if
any is designated. Regulations implementing this interagency
cooperation provision of the Act are codified at 50 CFR part 402.
Section 7(a)(4) of the Act requires Federal agencies to confer with the
Service on any action that is likely to jeopardize the continued
existence of a species proposed for listing or result in destruction or
adverse modification of proposed critical habitat. If a species is
listed subsequently, section 7(a)(2) of the Act requires Federal
agencies to ensure that activities they authorize, fund, or carry out
are not likely to jeopardize the continued existence of the species or
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into formal consultation with the Service.
Federal agency actions within the species habitat that may require
conference or consultation or both as described in the preceding
paragraph include management, construction, and any other activities
with the possibility of altering aquatic habitats, groundwater flow
paths, and natural flow regimes within the ranges of the Georgetown and
Salado salamanders. Such consultations could be triggered through the
issuance of section 404 Clean Water Act permits by the Army Corps of
Engineers or other actions by the Service, U.S. Geological Survey, and
Bureau of Reclamation; construction and maintenance of roads or
highways by the Federal Highway Administration; landscape-altering
activities on Federal lands administered by the Department of Defense;
and construction and management of gas pipelines and power line rights-
of-way by the Federal Energy Regulatory Commission.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered
wildlife. The prohibitions of section 9(a)(2) of the Act, codified at
50 CFR 17.21 for endangered wildlife, in part, make it illegal for any
person subject to the jurisdiction of the United States to take
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect; or to attempt any of these), import, export, ship
in interstate commerce in the course of commercial activity, or sell or
offer for sale in interstate or foreign commerce any listed species.
Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C. 3371-3378), it is also
illegal to possess, sell, deliver, carry, transport, or ship any such
wildlife that has been taken illegally. Certain exceptions apply to
agents of the Service and state conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered and threatened wildlife species under certain
circumstances. Regulations governing permits are codified at 50 CFR
17.22 for endangered wildlife, and at 50 CFR 17.32 for threatened
wildlife. With regard to endangered wildlife, a permit must be issued
for the following purposes: for scientific purposes, to enhance the
propagation or survival of the species, and for incidental take in
connection with otherwise lawful activities.
Required Determinations
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)
This rule does not contain any new collections of information that
require approval by OMB under the Paperwork Reduction Act. This rule
will not impose recordkeeping or reporting requirements on state or
local governments, individuals, businesses, or organizations. An agency
may not conduct or sponsor, and a person is not required to respond to,
a collection of information unless it displays a currently valid OMB
control number.
National Environmental Policy Act
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be
prepared in connection with listing a species as an endangered or
threatened species under the Act. We published a notice outlining our
reasons for this determination in the Federal Register on October 25,
1983 (48 FR 49244).
Data Quality Act
In developing this rule, we did not conduct or use a study,
experiment, or survey requiring peer review under the Data Quality Act
(Pub. L. 106-554).
References Cited
A complete list of all references cited in this rule is available
on the Internet at http://www.regulations.gov or upon request from the
Field Supervisor, Austin Ecological Services Field Office (see
ADDRESSES).
Author(s)
The primary author of this document is staff from the Austin
Ecological Services Field Office (see ADDRESSES) with support from the
Arlington, Texas, Ecological Services Field Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as follows:
PART 17--[AMENDED]
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245; unless
otherwise noted.
0
2. Amend Sec. 17.11(h) by adding entries for ``Salamander,
Georgetown'' and ``Salamander, Salado'' in alphabetical order under
Amphibians to the List of Endangered and Threatened Wildlife to read as
follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
[[Page 10293]]
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Species Vertebrate
---------------------------------------------------------------- population where When Critical Special
Historic range endangered or Status listed habitat rules
Common name Scientific name threatened
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* * * * * * *
Amphibians
* * * * * * *
Salamander, Georgetown............... Eurycea naufragia....... U.S.A. (TX)............ Entire T ......... NA NA
* * * * * * *
Salamander, Salado................... Eurycea chisholmensis... U.S.A. (TX)............ Entire T ......... NA NA
* * * * * * *
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* * * * *
Dated: February 14, 2014.
Daniel M. Ashe,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2014-03717 Filed 2-21-14; 8:45 am]
BILLING CODE 4310-55-P