Steller Sea Lion (Eumetopias jubatus)

Steller sea lions are found along the rim of the North Pacific Ocean from the Channel Islands in southern California to Hokkaido, Japan, and north into the Bering Sea and Sea of Okhotsk. Their center of abundance has been in the Aleutian Islands and Gulf of Alaska where historically nearly three-fourths of all Steller sea lions inhabiting U.S. territory were found. Two populations are currently recognized. The western population, located from Prince William Sound Alaska westward, has declined by about 85% since the 1970s for reasons that are poorly understood. However, they appear to be related to at least in part to prey availability. The eastern population, located east of Prince William Sound appears to be recovering slowly. Steller sea lions haulout on land to mate, bear their young, nurse, avoid predators, and rest. The location of rookeries is probably based on proximity to food sources, protection from terrestrial and marine predators, topography, surf conditions, and other factors. Steller sea lions are generally considered nonmigratory although some individuals, particularly juveniles and adult males, may disperse widely outside the summer breeding season. Most adult sea lions return to their birth site for reproduction. The various rookeries are therefore considered a metapopulation (i.e., a population consisting of smaller populations) with limited exchange between sites.

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