Under a directive from Congress, the U.S. Fish and Wildlife Service evaluated the feasibility of reintroducing sea otters to their historical range along the West Coast of the contiguous United States. The Service focused the assessment on northern California and Oregon, where potential sea otter reintroduction would have the greatest conservation value.
The Service’s assessment indicates reintroduction is feasible, but it does not provide a recommendation as to whether sea otter reintroduction should take place. Additional information and stakeholder input would be needed to help inform any future reintroduction proposal if the initiative moves forward.
Sea otters once lived across the north Pacific Rim from the northern islands of Japan to Baja California. By 1911, this heavily hunted species was nearly extinct and survived in only a few small disjunct populations. After slow population recovery and past reintroduction efforts, sea otters now again inhabit portions of their historical range. However, sea otters remain absent from the contiguous Pacific Coast, with the exception of central California, one island in southern California, and the northern coast of Washington. Sea otters in California are listed as threatened under the Endangered Species Act.
As a keystone species, sea otters play a fundamental role in the ecological health of nearshore ecosystems. Sea otters eat sea urchins and other marine grazers, which helps keep kelp forests and seagrass beds in balance. Their presence in the ocean enhances biodiversity, increases carbon sequestration by kelp and seagrass, and makes the ecosystem more resilient to the effects of climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.
Learn more about climate change . Additionally, reintroduction could increase the genetic diversity of recovering sea otter populations and contribute to the conservation of the threatened southern sea otter.
“If sea otters are reintroduced to northern California and Oregon, it would benefit both otters and the nearshore marine ecosystem,” said Craig Rowland, acting state supervisor for the Service’s Oregon office. “Additional work is needed to evaluate the possible impacts of a potential reintroduction as well as measures to offset these impacts. While we anticipate an overall socioeconomic benefit to coastal communities, we also recognize that some local shellfish fisheries could be affected.”
In the consideration of sea otter reintroduction, the Service’s assessment recommends stakeholder engagement in the identification of potential reintroduction sites and small-scale experimental reintroductions as next steps. If there is a move to formally propose the reintroduction of sea otters, the Service would initiate a public review process under the National Environmental Policy Act.
The Elakha Alliance, an Oregon nonprofit group, separately evaluated the feasibility of bringing sea otters back to the Oregon Coast. The Service partly funded this study. The feasibility assessment by the Service is intended to be read as a companion to the Elakha Alliance study, but it expands the geographic area under consideration in response to the request from Congress.
For more information and a copy of our report, please visit: https://www.fws.gov/project/sea-otter-feasibility-assessment.
Frequently Asked Questions
Why did the Service conduct a feasibility assessment for reintroducing sea otters?
Under a directive from Congress, the U.S. Fish and Wildlife Service evaluated the feasibility of reintroducing sea otters to the West Coast of the contiguous U.S., where sea otters historically thrived. The congressional mandate points to the sea otter’s “critical ecological role in the marine environment as a keystone species that significantly affects the structure structure
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Learn more about structure and function of the surrounding ecosystem.” Sea otters have been absent from most of the Pacific Coast since the early 1900s, since their near extinction as a result of the maritime fur trade.
How is this related to the Elakha Alliance feasibility study?
This assessment is intended to be read as a companion to a study of the feasibility of restoring sea otters to the Oregon coast recently released by the Elakha Alliance, a nonprofit organization. The Elakha Alliance Feasibility Study is available online at https://www.elakhaalliance.org/feasibility-study/. The Service had collaborated earlier with the Elakha Alliance to explore the possibility of restoring sea otters to the coast of Oregon. Because the Elakha Alliance has already compiled much of the best available scientific information on the topic, we largely adopt and incorporate their compendium of the science by reference, and to avoid duplication of effort in our assessment we emphasize the socioeconomic and legal aspects of feasibility. In addition, our assessment expands the scope of geographic consideration beyond the Oregon coast, but it does not include the entirety of the Pacific Coast. We focus our study of feasibility on the potential reintroduction of sea otters to the largest remaining gap in their range, on the coasts of northern California (from San Francisco Bay north) and Oregon.
What were the conclusions of the Service’s feasibility assessment?
The feasibility assessment reviewed the potential biological, socioeconomic, and legal impacts from a potential reintroduction in northern California and Oregon and recommended next steps. While the assessment indicates that reintroduction of sea otters to portions of the West Coast of the contiguous United States is feasible, additional information and stakeholder input are needed to help inform any future reintroduction proposal. The Service does not make any recommendation in this report as to whether reintroduction should take place. The feasibility assessment summarizes known information, identifies key data gaps, and presents stakeholder perspectives. In particular, because specific reintroduction sites have not yet been identified, one of the outstanding information needs to inform further consideration of reintroductions is a targeted assessment of the positive and negative local socioeconomic impacts.
Does this mean reintroduction is moving forward?
There is no active proposal to reintroduce sea otters at this time. Assessment of feasibility is the first step in any reintroduction effort, but it is not a reintroduction proposal. In the future, should there be a move to formally propose the reintroduction of sea otters, the U.S. Fish and Wildlife Service would need to initiate a National Environmental Policy Act review process that includes public review and engagement, including input from a broad range of stakeholders, prior to any formal decision.
What would be the objective of reintroduction?
Reintroducing sea otters to the Pacific Coast of the contiguous U.S. would advance two interrelated and overarching conservation goals:
1. Restoration of the species, Enhydra lutris, within important gaps in its historical range, including improving the status of the federally threatened subspecies, E. l. nereis or southern sea otter.
2. Restoration of ecosystem function, including enhancing ecosystem resilience, biodiversity, carbon sequestration, and resilience to the effects of climate change.
If the Service considers the possibility of reintroductions, what would be the next steps?
For next steps in considering potential reintroductions, the assessment recommends convening a series of structured decision-making workshops with scientific experts and key stakeholders to explore reintroduction options, including the identification of possible reintroduction sites; initiating a rigorous socioeconomic impact study to look at potential negative and positive local impacts; developing plans for pilot studies or small-scale experimental reintroductions to resolve key uncertainties in reintroduction methods; and integrating existing Oregon and California population models. Should there be a move to formally propose the reintroduction of sea otters, the U.S. Fish and Wildlife Service would need to initiate a public review process under the National Environmental Policy Act. This process would include opportunities for the public to review and comment prior to any formal decision.
What are the potential benefits of sea otter reintroduction?
As a keystone species, sea otters play a fundamental role in the natural food web, keeping importantelements of coastal ecosystems such as kelp forests and seagrass beds in balance. Reintroducing sea otters to areas where they historically lived but are currently absent could help restore functioning coastal ecosystems by enhancing ecosystem resilience, biodiversity, carbon sequestration, and resilience to the effects of climate change. A reintroduction could also increase gene flow between existing sea otter populations, contribute to the recovery of the threatened southern sea otter, and provide an overall significant socioeconomic benefit to local communities.
What are the potential challenges of sea otter reintroduction?
Despite the overall socioeconomic benefit expected in association with reintroduction, not all costs and benefits would be distributed equally. The shellfishing community in particular has expressed concerns about a potential reintroduction. We are exploring mechanisms to offset financial impacts that could be incorporated into any potential reintroduction proposals. We would also recommend the initiation of a local socioeconomic assessment by a team of qualified resource economists and social scientists at the earliest opportunity to provide accurate information for specific geographic areas that may serve as potential sites for sea otter reintroduction to the Pacific Coast.
Why is the feasibility assessment focusing on potential reintroduction efforts in Northern California and Oregon?
Today, there are two distinct sea otter subspecies in the U.S., the northern sea otter and the southern (or California) sea otter. Northern sea otters live in the nearshore waters of Alaska, British Columbia, and Washington State, and southern sea otters live along the central coast of California and at San Nicolas Island in southern California. Historically sea otters were distributed continuously along the north Pacific Rim, with Oregon serving as a transition zone between the two subspecies. Reintroducing sea otters to northern California and Oregon would help increase genetic diversity and long-term sustainability of sea otters in the wild by beginning to reconnect the northern sea otter and southern sea otter subspecies. Scientists have identified that northern California and Oregon have suitable habitat to support sea otters, and this area constitutes the largest remaining gap in the formerly continuous historical range of the sea otter.
Why was Washington not considered in the feasibility assessment?
We concluded that reintroductions in Washington would yield little conservation return for the investment of resources. Washington has already reestablished a growing population of sea otters that will likely continue to expand southward in Washington State. Also, since sea otters from the Washington population are occasionally found in Oregon, there would be opportunity for a potential Oregon population to genetically mix with sea otters from Washington.
What benefits do sea otters provide to people and ecosystems?
Sea otters benefit nearshore marine ecosystems, contribute to climate change resiliency, and can support local economies through eco-tourism. Because they are efficient predators and consume large quantities of marine invertebrates, sea otters play a significant role in nearshore marine ecosystems, enhancing kelp forests and seagrass beds. Kelp forests provide numerous benefits, including habitat for hundreds of invertebrate and fish species, reductions in coastal erosion, and carbon storage that can moderate climate change. Seagrasses also provide important benefits, such as nursery habitat for many other species, shoreline protection, and carbon sequestration.
How do sea otters help mitigate climate change?
Sea otters help maintain kelp by preying on sea urchins, which can clear-cut kelp forests when left unchecked. Sea otters in British Columbia and central California have also been shown to enhance seagrass, though by different mechanisms. In British Columbia, sea otters enhance seagrass genetic diversity by creating disturbance while digging for buried prey. This disturbance causes the seagrass to reproduce sexually instead of asexually, increasing its genetic diversity and thus its resilience to stressors. In central California, sea otters increase seagrass abundance and resilience to human-caused pollution by preying on crabs, which eat sea slugs and isopods. In controlling the predators of these mid-size underwater grazers, sea otters allow the sea slugs and isopods to graze the pollution-fueled algal epiphytes that coat the seagrass blades, allowing sunlight to penetrate and the seagrass to flourish.
Kelp and seagrass capture carbon dioxide (CO2) from the atmosphere and transform it into organic carbon. Some of this carbon is stored in their bodies, and some is sequestered in the deep ocean or in sediments where it is no longer cycling and contributing to climate change. Kelp and seagrass protect shorelines from erosion caused by sea level rise and increased storm intensity, and they locally reduce ocean acidification, which results from the ocean’s absorption of excess atmospheric CO2. Ocean acidification can be devastating to calcifying organisms, such as the shell-forming species that constitute much of sea otters’ prey.
What happens next?
The assessment outlines a series of next steps if reintroduction is considered further. The assessment recommends convening a series of structured decision-making workshops with scientific experts and key stakeholders to explore reintroduction options, including the identification of potential reintroduction sites; initiating a rigorous socioeconomic impact study to look at potential negative and positive local impacts; developing plans for pilot studies or small-scale experimental reintroductions to resolve key uncertainties in reintroduction methods; and integrating existing Oregon and California population models.
