Inter-Research > ESR > v44 > p159-176  
ESR
Endangered Species Research

via Mailchimp

ESR 44:159-176 (2021)  -  DOI: https://doi.org/10.3354/esr01101

Informing sea otter reintroduction through habitat and human interaction assessment

Dominique V. Kone1,4,*, M. Tim Tinker2, Leigh G. Torres3

1College of Earth, Ocean, and Atmospheric Science, Marine Mammal Institute, Oregon State University, 2030 SE Marine Science Drive, Newport, OR 97365, USA
2Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
3Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, 2030 SE Marine Science Drive, Newport, OR 97365, USA
4Present address: California Ocean Science Trust, 1111 Broadway, Oakland, CA 94607, USA
*Corresponding author:

ABSTRACT: Sea otters Enhydra lutris have been absent from Oregon, USA, following their extirpation over a century ago. Stakeholder groups and native tribes are advocating for reintroduction to restore historic populations. We investigated the potential for successful reintroduction by: (1) estimating expected equilibrium sea otter densities as a function of habitat variables to assess sea otter habitat in Oregon; and (2) spatially relating areas of high expected densities to human activities (e.g. fisheries, recreation, vessel activity, protected areas) to anticipate potential disturbance or fishery resource competition. We estimated that 4538 (1742-8976; 95% CI) sea otters could exist in Oregon, with higher expected abundance (N = 1551) and densities ( = 2.45 km-2) within the southern region. Most core habitat areas (97%), representing clusters of high expected densities, overlapped with some form of human activity. While commercial shipping and tow lanes overlapped little (1%) with core habitat areas, recreational activities (58%) and fisheries (76%) had a higher degree of overlap, posing higher disturbance risk. We anticipate higher resource competition potential with the commercial red sea urchin fishery (67% of harvest areas) than the commercial Dungeness crab fishery (9% of high-catch crabbing grounds). Our study presents the first published carrying capacity estimate for sea otters in Oregon and can provide population recovery targets, focus attention on ecological and socioeconomic considerations, and help to inform a recovery plan for a resident sea otter population. Our findings suggest current available habitat may be sufficient to support a sea otter population, but resource managers may need to further investigate and consider whether current human activities might conflict with reestablishment in Oregon, if plans for a reintroduction continue.


KEY WORDS: Sea otter · Enhydra lutris · Oregon · Reintroduction · Habitat · Carrying capacity · Fisheries · Conservation


Full text in pdf format 
Cite this article as: Kone DV, Tinker MT, Torres LG (2021) Informing sea otter reintroduction through habitat and human interaction assessment. Endang Species Res 44:159-176. https://doi.org/10.3354/esr01101

Export citation
Mail this link - Contents Mailing Lists - RSS
Facebook - - linkedIn