The population of northern fur seal (Callorhinus ursinus) pups on Bogoslof Island was estimated using shear-sampling, a mark-recapture method, in August 2007. A preliminary analysis indicates a continued increase in pup production on Bogoslof Island since the last estimate in 2005. Some of the increase in pup production may be a result of emigration of adults from rookeries on St. Paul and St. George Islands, where pup numbers have been declining. While on Bogoslof Island, staff of the Alaska Ecosystems Program instrumented 10 adult female northern fur seals with satellite tracking devices to continue investigations on summer foraging behavior and winter migration.
By Tonya Zeppelin
Steller Sea Lion Pup Survey
In June and July 2007, using the chartered research vessel Norseman II and the Alaska Maritime National Wildlife Refuge research vessel Tiglax, the Alaska Ecosystems Program conducted its annual cruise to survey Steller sea lion (Eumetopias jubatus) pups from the western Aleutian Islands through the central Gulf of Alaska. In order to assess pup condition and health status, morphometrics (weight, girth, length) and tissue samples (blood, tissue, fecal) were collected from 50 randomly selected pups at specific rookeries according to our biennial sampling schedule.
Necropsies were conducted on freshly-dead pups at seven sites, and tissue samples of the dead pups were saved for histology, contaminants, and parasite studies. Additionally, we collected 59 scats from the eastern and central Gulf of Alaska regions and 121 scats from the central and western Aleutian Islands for dietary analysis.
