Boat-Based Population Surveys of Sea Otters ('Enhydra lutris') in Prince WilliamSound, Alaska, Following the EXXON VALDEZ Oil Spill. Marine Mammal Study 6-6. EXXON VALDEZ Oil Spill State/Federal Natural Resource Damage Assessment Final Report

摘要

Following the Exxon Valdez oil spill, boat-based population surveys of marinebirds and sea otters were periodically conducted within Prince William Sound, Alaska, between June 1989 and July 1991. The purpose of this research was to estimate post-spill sea otter density and abundance for comparison with pre-spill data in order to determine the injury to the population. Within the oiled area, sea otter density within shoreline stratum (defined as a 200m-wide strip adjacent to the shore) was 35% lower than the pre-spill density, suggesting a significant oil effect. Sea otter density in the shoreline stratum of unoiled areas was not significantly different than pre-spill density. Declines in shoreline sea otter density between 1989 and 1990 in both oiled and unoiled areas suggested a possible Sound-wide decline in the sea otter population. However, comparison of abundance estimates of all survey strata combined showed that the sea otter population in both oiled and unoiled areas of Prince William Sound were not significantly different between July of 1989, 1990, and 1991.