The Steller sea lion Eumetopias jubatus is the largest species of the eared seals.
The eastern stock of this mammal is listed as a threatened species and the western stock is listed as endangered. The Steller sea lion has attracted much attention due to significant, unexplained declines in their numbers over a large portion of their range in Alaska. The populations of the Western stock has been estimated to have fallen by 70-80% since the 1970's. One possible cause of their decline is the overfishing of Alaska pollock, herring and other fish stocks in the Gulf of Alaska. Other possible reasons for their decline are indirect effects of prey species composition due to possible climate change, and possible effects of disease or contaminants.
