Aerial and Land-Based Surveys of Steller Sea Lions (Eumetopias jubatus) in Alaska, June and July 1997 and 1998
Sease JL and Loughlin TR. 1999. Aerial and Land-Based Surveys of Steller Sea Lions (Eumetopias jubatus) in Alaska, June and July 1997 and 1998. NOAA Technical Memorandum. NMFS-AFSC-100. US National Marine Fisheries Service; Alaska Fisheries Science Center; NOAA. Seattle, WA
The National Marine Fisheries Service (NMFS) and the Alaska Department of Fish and Game (ADF&G) conducted aerial and land-based surveys of Steller sea lions (Eumetopias jubatus) in Alaska during June and July 1997 and 1998. During a limited-range survey in 2997, we counted a total of 16,249 non-pup Steller sea lions on 127 rookery and haul-out sites in the central and western Gulf of Alaska and eastern Aleutian Islands. In 1998, we counted a total of 39,597 non-pups on 236 rookery and haul-out sites Alaska-wide. Of these sea lions, 20,976 were on 33 trend rookeries, indicating declines of 7.0% from 1996 and 24.0% from 1990. The estimated average annual decline for the trend rookeries was 3.5% from 1990 to 1998. The western stock of Steller sea lions in Alaska includes animals from the eastern Gulf of Alaska through the western Aleutian Islands. At 30 western-stock trend rookeries, we counted 14,368 non-pups in 1998, which indicated declines of 12.2% from 1996 and 35.0% from 1990. The estimated average annual rate of decline from 1990 to 1998 was 5.4%. Complete western-stock counts were not surveyed in the eastern Gulf of Alaska in 1998. Counts for rookery and haul-out trend sites in the central Gulf of Alaska through the western Aleutian Islands suggested western-stock declines of 9.3% from 1996 and 26.6% from 1991, or an estimated average annual decline of 4.3% over the 7-year period.
- Type
- Published Report
- Authors
- Sease, J; Loughlin, T
- Date of Issue
- 1999-04
- Publisher
- US National Marine Fisheries Service; Alaska Fisheries Science Center; NOAA
- Units
- ANIA , GLBA , KATM , KEFJ , SITK , WRST
- Keywords
- Alaska, Eumetopias jubatus, Land-Based Surveys, Marine, Marine Mammals, Steller Sea Lions, Wildlife