The Stellar Sea Lions are the fourth largest of all seal species. The population of stellar sea lion has declined by more than 60% due to both natural and human threats. They are threatened by killer whales, fishing and harvest by Native Alaskans and Canadians for meat, oil, and other by-products make it a critically endangered species.
These giant species feed off of fish, squid, and octopus. In between the 1980's and 1990's the population of stellar sea lions decreased highly for factors that scientists are unsure of. Some possibilities for this decrease include a growth in parasites, disease, their biggest predators the killer whale, quality and supply of food, environmental issues and nutritional stress caused by natural changes in amount of key prey species, or by the competition with other species and humans for nutrition.