Aerial and Land-Based Surveys of Steller Sea Lions (Eumetopias jubatus) from the Western Stock in Alaska, June and July 2001 and 2002

摘要

The National Marine Fisheries Service (NMFS) conducted aerial and land-based surveys of the western stock of Steller sea lions (Eumetopias jubatus) in Alaska during June and July of 2001 and 2002 at all sites from 144 degrees W to 172 degrees E, the westernmost point in the Aleutian Islands. Survey effort 2001 was restricted to pup counts at selected sites in the Aleutian Islands and the Gulf of Alaska. The 2002 survey included the entire western stock: aerial surveys of non-pups at all sites and pup counts at all rookeries except those counted in 2001. In June 2002, a total of 26,602 non-pups were counted on all surveyed sites (n=259). Of these non-pups, 14,320 were on 30 trend rookeries and 5,020 were on 54 trend haul-out sites for a total of 19,340 on all 84 trend sites. This was an increase of 5.5% for all trend sites and 6.8% for trend rookeries from June 2000, the first region-wide increase observed since standardized aerial survey began in the 1970s.