2009 was a good year for Steller sea lion pups. Between June 24 and July 15, 2009, Steller sea lion biologists conducted an aerial photographic survey of all the rookeries and major haulouts throughout most of the sea lions' range in Alaska. The goal was to count Steller sea lion pups.
Steller sea lions in Alaska are separated into two stocks. The dividing line is Cape Suckling, near Cordova. Sea lions in Southeast Alaska and in the eastern Gulf of Alaska are part of the eastern stock. Sea lions in Prince William Sound and points west out along the Aleutians are in the western stock.
The number of Steller sea lion has declined significantly in recent decades, especially the western stock, which is listed as threatened under the Endangered Species Act. But pup numbers are up in some areas. Pup production by Alaska's western stock increased from 9,950 in 2005 to 11,120 in 2009, but there was considerable variability. Numbers improved in Gulf of Alaska and in the eastern Aleutians, but continue to decline in the central and western Aleutian Islands.
The number of pups in the eastern stock was 7,462, which exceeded any previous counts going back to the 1960s. That indicates pup production has increased almost 4 percent per year at Southeast Alaska's five major rookeries since the late 1970s.