Distribution, age, and sex composition of sea otter carcasses recovered during the response to the T/V Exxon Valdez oil spill

Nearly 900 sea otter (Enhydra lutris) carcasses were recovered in or adjacent to coastal areas affected by the T/V Exxon Valdez oil spill. The time of carcass recovery and the condition of carcasses indicate that most oil spill-induced mortality occurred early in the response period. In fact, by 19 May about 70% of the carcasses had been found. The majority of the carcasses (56%) were from Prince William Sound, suggesting that mortality was more acute there than in other geographic areas. Examination of the recovered carcasses indicated that more adult female sea otters were killed by the oil in Prince William Sound and along the Kenai Peninsula than other sex and age cohorts, reflecting greater abundance of adult females in those regions. Many of the adult females in those areas were pregnant or lactating. Pups made up a higher proportion of the carcasses collected in the western portion of the spill zone, reflecting the advanced pupping chronology at the time the search effort reached the Alaska Peninsula and the Kodiak Archipelago.