Aerial Surveys of Sea Otters in the Northwestern Gulf of Alaska and Southeastern Bering Sea

摘要

Aerial surveys were conducted in 1986 in the northwestern Gulf of Alaska and southeastern Bering Sea to determine the distribution and abundance of sea otters. A total of 7,580 groups of 22,791 sea otters were observed in the Shumagin, North Aleutian Basin, and St. George Basin (Fox Islands) planning areas. Sea otter densities were highest in the Shumagin Planning Area, lowest in the St. George Basin, and intermediate in the North Aleutian Basin. Areas of peak use shifted seasonally within the North Aleutian Basin and Shumagin planning areas. However, there was no indication of a major seasonal movement of sea otters between these two planning areas. Sea otter numbers have apparently increased in the Fox, Pavlof, and northern Shumagin Islands and decreased in the Sanak and southern Shumagin Islands since earlier surveys. Total abundance for the study area was estimated between 26,775 and 29,295 without correcting for animals submerged or missed on the surface. These estimates suggest the sea otter population has declined in the North Aleutian Basin and increased in the Shumagin area and St. George Basin.