Stock structure of sea otters (Enhydra lutris kenyoni) in Alaska.

Sea otters in Alaska are recognized as a single subspecies (Enhydra lutris kenyoni) and currently managed as a single, interbreeding population. Howev er, geographic and behavioral mechanisms undoubtably constrain sea otter mo vements on much smaller scales. This pager applies the phylogeographic meth od (Dizon et al. 1992) and considers distribution, population response, phe notype and genotype data to identify stocks of sea otters within Alaska. Th e evidence for separate stock identity is genotypic tall stocks), phenotypi c (Southcentral and Southwest stocks), and geographic distribution (Southea st stock), whereas population response data are equivocal tall stocks). Dif ferences in genotype frequencies and the presence of unique genotypes among areas indicate restricted gene flow. Genetic exchange may be limited by li ttle or no movement across proposed stock boundaries and discontinuities in distribution at proposed stock boundaries. Skull size differences (phenoty pic) between Southwest and Southcentral Alaska populations further support stock separation. Population response information was equivocal in either s upporting or refuting stock identity. On the basis of this review, we sugge st the following: (1) a Southeast stock extending from Dixon Entrance to Ca pe Yakataga; (2) a Southcentral stock extending from Cage Yakataga to Cape Douglas including Prince William Sound and Kenai peninsula cease; and (3) a Southwest stock including Alaska Peninsula coast, the Aleutians to Attu Is land, Barren, Kodiak, Pribilof Islands, and Bristol Bay.