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Home/Species/ Northern Sea Otter

Enhydra lutris kenyoni

Wilson, 1991

Northern Sea Otter

T2T2 (G4T2T3) Found in 124 roadless areas NatureServe Explorer →
T2T2Global Rank
PS:LTESA Status
Identity
Unique IDELEMENT_GLOBAL.2.101611
Element CodeAMAJF09013
Record TypeSPECIES
ClassificationSubspecies
Classification StatusStandard
Name CategoryVertebrate Animal
CITESAppendix II
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassMammalia
OrderCarnivora
FamilyMustelidae
GenusEnhydra
USESAPS:LT
COSEWICSC
Concept Reference
Wilson, D.E., M.A. Bogan, R.L. Brownell, Jr., A.M. Burdin, and M.K. Maminov. 1991c. Geographic variation in sea otters, Enhydra lutris. Journal of Mammalogy 72:22-36.
Taxonomic Comments
There has been some disagreement as to whether the recognition of subspecies is warranted. Three subspecies are currently recognized: E. lutris lutris from Asia to the Commander Islands, E. l. nereis in California, and E. l. kenyoni in Alaska (Wilson et al. 1991).
Conservation Status
Review Date2008-01-14
Change Date2008-01-14
Edition Date2008-01-14
Edition AuthorsGotthardt, T. A., and C. Coray. Reviewed by Angela Doroff, USFWS, Anchorage, AK.
Range Extent20,000-2,500,000 square km (about 8000-1,000,000 square miles)
Rank Reasons
Ranges along the margin of the Pacific Ocean from the Aleutian Islands, Alaska, to Washington; global population is relatively stable in southcentral and southeastern Alaska, and a small population is growing along the coast of Washingtion; northern sea otters translocated to British Columbia number approximately 2,500 and are listed as a Species at Risk; severe population declines (as great as 70%) have occurred in the Southwest Alaska stock, and the population is being considered for listing as threatened under the U.S. Endangered Species Act; as of 2000, the estimated number of sea otters of subspecies kenyoni was less than 75,000 world-wide; this subspecies is vulnerable to oil spills, conflicts and incidental take in commercial fisheries, and potential increases in killer whale predation.
Range Extent Comments
This subspecies occurs in the Aleutian Islands, southern Alaska, British Columbia, and Washington; it was extirpated and later reintroduced in southeastern Alaska, British Columbia, and Washington; extirpated and unsuccessfully reintroduced in the Pribilof Islands and Oregon.
Threat Impact Comments
In various parts of the range, conflicts with commercial fisheries (gill and trammel nets, crab traps) and activities associated with oil and gas exploration, development, and transportation may be the greatest threats. Commercial fisheries are not a major threat in Alaska (USFWS 1995 stock assessment). Brody et al. (1996) determined that an oil spill of Exxon Valdez size, occurring at the Monterey Peninsula, California, would kill at least 50% of the total California sea otter population. Between 750 and 2,650 animals died as a result of the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska (Garrot et al. 1993, Garshelis 1997).
Ecology & Habitat

Habitat

Occupy nearly all coastal marine habitats, from fine sediment bays and estuaries to rocky shores exposed to oceanic swells. Habitat area depends on slope of the sea floor and where depth contour intervals are widely spaced, may extend far offshore to include shallow areas. Highest densities of sea otters occur in water less than 40 m deep, although they can be found in water up to 200 m deep (Bodkin and Udevitz 1999, Bodkin and Kenyon 2003). Generally occur within 2 km of shore, especially shallows with kelp beds and abundant shellfish. In rough weather, takes refuge among kelp, or in coves and inlets. Often comes ashore in Alaska; births may occasionally occur onshore in Alaska (USFWS 2004).

Reproduction

See files for Enhydra lutris.
Other Nations (2)
United StatesN2
ProvinceRankNative
OregonSHYes
WashingtonS2Yes
AlaskaS3Yes
CanadaN3
ProvinceRankNative
British ColumbiaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial development———
1.2 - Commercial & industrial areas———
3 - Energy production & mining———
3.1 - Oil & gas drilling———
4 - Transportation & service corridors———
4.3 - Shipping lanes———
5 - Biological resource use———
5.4 - Fishing & harvesting aquatic resources———
9 - Pollution———
9.2 - Industrial & military effluents———

—

Roadless Areas (124)
Alaska (124)
AreaForestAcres
AaronTongass National Forest78,719
AnanTongass National Forest36,666
Bay of PillarsTongass National Forest27,492
Behm IslandsTongass National Forest4,777
Bering LakeChugach National Forest965,076
BradfieldTongass National Forest199,016
CalderTongass National Forest9,857
CamdenTongass National Forest36,793
CastleTongass National Forest49,289
ChichagofTongass National Forest555,858
Chilkat-West Lynn CanalTongass National Forest199,772
ChristovalTongass National Forest9,129
Chugach-1Chugach National Forest1,317
Chugach-10Chugach National Forest112
Chugach-11Chugach National Forest104
Chugach-12Chugach National Forest8,116
Chugach-14Chugach National Forest184
Chugach-15Chugach National Forest56
Chugach-17Chugach National Forest19,954
Chugach-18Chugach National Forest26
Chugach-19Chugach National Forest18
Chugach-2Chugach National Forest671
Chugach-20Chugach National Forest132
Chugach-21Chugach National Forest634
Chugach-22Chugach National Forest801
Chugach-3Chugach National Forest27,386
Chugach-4Chugach National Forest2,797
Chugach-5Chugach National Forest114
Chugach-6Chugach National Forest503
Chugach-8Chugach National Forest21,559
Chugach-9Chugach National Forest29
ClevelandTongass National Forest189,447
College FiordChugach National Forest1,130,818
Copper River WetlandsChugach National Forest85,972
CrystalTongass National Forest18,972
Dall IslandTongass National Forest105,780
Douglas IslandTongass National Forest28,065
DukeTongass National Forest45,091
East KuiuTongass National Forest27,611
East MitkofTongass National Forest8,795
East WrangellTongass National Forest7,630
EudoraTongass National Forest195,022
Fake PassTongass National Forest479
FanshawTongass National Forest48,248
Fidalgo-GravinaChugach National Forest257,968
Five MileTongass National Forest19,459
Freshwater BayTongass National Forest44,933
FrostyTongass National Forest39,941
Game CreekTongass National Forest54,469
GravinaTongass National Forest37,381
Green RocksTongass National Forest11,093
Greens CreekTongass National Forest27,177
HardingTongass National Forest174,349
Hoonah SoundTongass National Forest79,764
HydaburgTongass National Forest11,171
Juneau UrbanTongass National Forest101,581
Juneau-Skagway IcefieldTongass National Forest1,187,268
KadinTongass National Forest2,035
KartaTongass National Forest52,117
KasaanTongass National Forest7,611
Kasaan BayTongass National Forest7,363
Kashevarof IslandsTongass National Forest4,747
KekuTongass National Forest10,869
Kenai MountainsChugach National Forest306,600
KogishTongass National Forest65,216
KosciuskoTongass National Forest64,134
LindenbergTongass National Forest25,855
MadanTongass National Forest68,553
Mansfield PeninsulaTongass National Forest54,991
ManzanitaTongass National Forest8,401
McKenzieTongass National Forest83,103
Middle KruzofTongass National Forest14,724
MissionaryTongass National Forest16,675
MontagueChugach National Forest204,875
MosmanTongass National Forest53,492
Neka BayTongass National Forest7,142
Neka MountainTongass National Forest6,138
Nellie JuanChugach National Forest713,697
North BaranofTongass National Forest314,089
North ClevelandTongass National Forest105,288
North EtolinTongass National Forest40,993
North KruzofTongass National Forest33,146
North KupreanofTongass National Forest114,660
North RevillaTongass National Forest215,430
NutkwaTongass National Forest53,735
Outer IslandsTongass National Forest99,862
Pavlof-East PointTongass National Forest5,399
Point AugustaTongass National Forest15,482
Point CravenTongass National Forest10,906
Port AlexanderTongass National Forest120,681
Prince William Sound Is.Chugach National Forest118,698
QuartzTongass National Forest143,003
RedoubtTongass National Forest68,347
RevillaTongass National Forest29,298
RhineTongass National Forest23,010
Rocky PassTongass National Forest78,163
Salmon BayTongass National Forest22,793
SarkarTongass National Forest51,908
SecurityTongass National Forest31,428
Sheridan GlacierChugach National Forest224,683
Sitka SoundTongass National Forest13,459
Sitka UrbanTongass National Forest112,003
Soda BayTongass National Forest78,091
South EtolinTongass National Forest26,293
South KruzofTongass National Forest55,193
South KuiuTongass National Forest62,452
South KupreanofTongass National Forest216,816
South RevillaTongass National Forest52,105
South ZaremboTongass National Forest36,285
Southeast WrangellTongass National Forest18,377
SpiresTongass National Forest533,746
Suemez IslandTongass National Forest19,903
SukkwanTongass National Forest44,369
SullivanTongass National Forest67,323
Taku-SnettishamTongass National Forest664,928
Twenty MileChugach National Forest198,775
Upper SitukTongass National Forest16,789
West WrangellTongass National Forest10,291
West ZaremboTongass National Forest6,786
WhitestoneTongass National Forest5,638
Windham-Port HoughtonTongass National Forest161,952
WoewodskiTongass National Forest10,136
WoronkofskiTongass National Forest11,114
Yakutat ForelandsTongass National Forest323,648
References (23)
  1. Bodkin, J. L. and K. W. Kenyon. 2003. Sea otter. Pages 735-? in G.A. Feldhamer, B.C. Thompson, and J.A. Chapman, (eds) Wild mammals of North America: biology, management, and conservation. 2nd Edition. Johns Hopkins University Press.
  2. Bodkin, J. L. and M.S. Udevitz. 1999. An aerial survey method to estimate sea otter abundance. Pages 13-26 in Garner, G.W., et al. (eds.). Marine mammal survey assessment methods. A.A Balkema, Rotterdam
  3. Bodkin, J.L., K.A. Kloecker, G.G. Esslinger, D.H. Monson, J.D. DeGroot, and J. Doherty. 2001. Sea otter studies in Glacier Bay National Park and Preserve. Annual Report 2001.
  4. Brody, A. J., K. Ralls, and D. B. Siniff. 1996. Potential impact of oil spills on California sea otters: implications of the Exxon Valdez spill in Alaska. Marine Mammal Science 12:38-53.
  5. Cronin, M. A., J. Bodkin, B. Ballachey, J. Estes, and J. C. Patton. 1996. Mitochondrial-DNA variation among subspecies and populations of sea otters (<i>Enhydra lutris)</i>. Journal of Mammalogy 77:546-557.
  6. Garrot, R.A., L.L. Eberhard, and D.M. Burn. 1993. Mortality of sea otters in Prince William Sound following the <i>Exxon Valdez</i> oil spill. Marine Mammal Science 9: 343-359.
  7. Garshelis, D.L. 1997. Sea otter mortality from carcasses collected after the <i>Exxon Valdez</i> oil spill. Conservation Biology 11: 905-916.
  8. MacAskie, I. 1986. Updated Status Report on the sea otter, <i>Enhydra lutris</i>, in Canada. Committee on the Status of Endangered Wildlife in Canada. 16 pp.
  9. Matthews, J.R. and C.J. Moseley (eds.). 1990. The Official World Wildlife Fund Guide to Endangered Species of North America. Volume 1. Plants, Mammals. xxiii + pp 1-560 + 33 pp. appendix + 6 pp. glossary + 16 pp. index. Volume 2. Birds, Reptiles, Amphibians, Fishes, Mussels, Crustaceans, Snails, Insects, and Arachnids. xiii + pp. 561-1180. Beacham Publications, Inc., Washington, D.C.
  10. Raloff, J. 1993. An otter tragedy. Science News 143:200-202.
  11. Reeves, R. R., B. S. Stewart, and S. Leatherwood. 1992. The Sierra Club Handbook of Seals and Sirenians. Sierra Club Books, San Francisco, California. xvi + 359 pp.
  12. Riedman, M. L., and J. A. Estes. 1990. The sea otter (<i>Enhydra lutris</i>): behavior, ecology, and natural history. U.S. Fish and Wildlife Service Biological Report 90(14). 126 pp.
  13. Scribner, K.T., Bodkin, J., Ballachey, B., Fain, S.R., Cronin, M.A.,and Sanchez, M. 1997. Population genetic studies of the sea otter (<i>Enhydra lutris</i>): a review and interpretation of available data. Pages 197-208 <i>In</i> A.E. Dizon, S.J. Chivers, and W.F. Perrin (eds.). Molecular genetics of marine mammals. Spec. Publ. No. 3, Society for Marine Mammals, Lawrence, Kans. pp. 197-208.
  14. U.S. Fish and Wildlife Service (USFWS). 11 February 2004. Endangered and threatened wildlife and plants; listing the southwest Alaska distinct population segment of the northern sea otter (<i>Enhydra lutris kenyoni</i>) as threatened. Proposed Rules. Federal Register 69(28): 6600- 6621.
  15. U.S. Fish and Wildlife Service (USFWS). 13 June 2002. Review of species that are candidates or proposed for listing as endangered or threatened; annual notice of findings on recycled petitions; annual description of progress on listing actions. Federal Register 67(114):40657-40679.
  16. U.S. Fish and Wildlife Service (USFWS). 1995. Stock assessment - Sea Otter (<i>Enhydra lutris</i>), Alaska stock. Marine Mammals Management, Anchorage, AK; 5 pp.
  17. U.S. Fish and Wildlife Service (USFWS). 2000. Notice of designation of the northern sea otter in the Aleutian Islands as a candidate species. Federal Register 65:67343-67345.
  18. U.S. Fish and Wildlife Service (USFWS). 2000. Notice of designation of the Northern Sea Otter in the Aleutian Islands as a candidate species. Federal Register 65:67343-67345.
  19. U.S. Fish and Wildlife Service (USFWS). 2001. 2 November 2001. Marine mammals; finding on petition to list the Alaska stock of Sea Otters as depleted. Federal Register 66(213):55693-55697.
  20. U.S. Fish and Wildlife Service (USFWS). 2001. 30 October 2001. Review of plant and animal species that are Candidates or proposed for listing as Endangered or Threatened, annual notice of findings on recycled petitions, and annual description of progress on listing actions; proposed rule. Federal Register 66(210):54808-54832.
  21. U.S. Fish and Wildlife Service (USFWS). 9 August 2005. Endangered and threatened wildlife and plants; determination of threatened status for the Southwest Alaska Distinct Population Segment of the Northern Sea Otter (<i>Enhydra lutris kenyoni</i>). Federal Register 70(152): 46366-46386.
  22. Watson, J. C., G. M. Ellis, T. G. Smith, and J.K.B. Ford. 1997. Updated status of the sea otter, <i>Enhydra lutris</i>, in Canada. Canadian Field-Naturalist 111:277-286.
  23. Wilson, D.E., M.A. Bogan, R.L. Brownell, Jr., A.M. Burdin, and M.K. Maminov. 1991c. Geographic variation in sea otters, <i>Enhydra lutris</i>. Journal of Mammalogy 72:22-36.