Initial Reviews on ESA Petitions for Four Species Completed

The U.S. Fish and Wildlife Service has completed 90-day findings on petitions to list four species under the Endangered Species Act (ESA). Based on our review, we find that the petitions to list the Fish Lake Valley tui chub and delist the southern sea otter present substantial information that the petitioned actions may be warranted. The Service will add these species to the National Listing Workplan and initiate status reviews for each.

We find that the petition to list the Pryor Mountain mustang population does not present substantial information that the population is a listable entity under the ESA or that the population may meet criteria in our distinct population segment (DPS) policy to warrant listing as a DPS. We find that the petition to revise the critical habitat designation for the Sonora chub does not present substantial information indicating the petitioned action may be warranted. Therefore, we will not be initiating status reviews for these species.

The southern sea otter, also known as the California sea otter, can be found in nearshore areas along the central California coast. As a keystone species, they play a fundamental role in the natural food web by keeping important elements of coastal ecosystems like kelp forests and seagrass beds in balance. Southern sea otters were hunted to near extinction during the fur trade of the 1700s and 1800s. The species was listed as threatened under the ESA in 1977. We find that the petition presents substantial scientific or commercial information indicating that delisting the southern sea otter may be warranted. We will fully evaluate all potential threats during our 12-month status review, pursuant to the act’s requirement to review the best scientific and commercial information available when making that finding.

The Fish Lake Valley tui chub is a small desert fish that prefers pool habitats with low current velocities and dense aquatic vegetation to provide adequate cover and habitat for insect food items. Tui chubs typically are found in alkaline waters with summer water temperatures exceeding 20° Celsius (68° Fahrenheit). The species historically occurred within Fish Lake, Lahontan Basin and Central Great Basin of Nevada and Owens and Mojave rivers in California. As habitat was degraded or lost, the species was eventually limited to one population in Fish Lake Valley in southwest Nevada. By 1986. Fish Lake Valley tui chub were determined to be extirpated from Fish Lake and known only to occur in isolated wetlands on a private ranch in Fish Lake Valley. This extirpation was due to the annual drying of the lake during irrigation season. The Fish Lake tui chub is considered a state protected fish classified as a state sensitive species by Nevada. The Service will fully evaluate all potential threats during our 12-month status review, pursuant to the ESA’s requirement to review the best available scientific information when determining whether or not to list a species.

The Pryor Mountain mustang population is descended from domestic horses that were introduced to the southwestern United States by Spaniards in the 16th century. We consider these horses as feral, non-native animals that compete with native wildlife for resources and are potentially detrimental to the ecosystems upon which endangered and threatened species depend. Service policy supports the management and removal of feral horses to ensure they do not adversely impact native species and their habitats. We received a petition to list the Pryor Mountain Mustang population as a DPS. Based on our review of the petition, however, we found that the population does not meet any DPS considerations regarding significance and is not a listable entity under the act. 

The Sonora chub is a desert fish in the minnow family found in southeastern Arizona, about 15.5 miles west of Nogales in Santa Cruz County and in the Rio de Concepción (also known as Rio Magdalena) drainage in Sonora, Mexico. The species was listed as a threatened species with critical habitat in 1986. At the time of listing, Sonora chub was known to occur in Sycamore Creek in Santa Cruz County. Since its listing, the species was discovered in 1995 in California Gulch in Santa Cruz County and its tributary streams. In reviewing the information presented in the petition, we find the petition does not provide substantial scientific information indicating that revising critical habitat for Sonora chub may be warranted.

The ESA allows citizens to petition the Service to add species to the ESA list, remove species from the list, and to reclassify species already on the list. To the maximum extent possible, the Service issues a finding on a petition within 90 days of the petition’s receipt.

Substantial 90-day findings represent a relatively low bar, requiring only that the petitioner provide information that the petitioned action may be warranted. The next steps involve in-depth status reviews and analyses using the best available science and information to arrive at a 12-month finding. The public can play an important role by sharing relevant information with the Service.

The Federal Register docket numbers and links for the substantial petition findings in this batch are:

The notice for the above findings will be available in the Federal Register Reading Room on Aug. 22, 2022 at https://www.federalregister.gov/public-inspection on the 2022 Notices link under Endangered and Threatened Wildlife and Plants.

For more information on the ESA listing process, including 90-day findings and status reviews, please go to www.fws.gov/media/listing-species-threatened-or-endangered.

The U.S. Fish and Wildlife Service works with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. For more information, visit www.fws.gov, or connect with us through any of these social media channels: Facebook, Twitter, Flickr, YouTube.