Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable
Comments: In various parts of the range, conflicts with commercial fisheries (gill and trammel nets, crab traps) and activities associated with oil and gas exploration, development, and transportation may be the greatest threats. Commercial fisheries are not a threat in Alaska (USFWS 1995 stock assessment). Brody et al. (1996) determined that an oil spill of Exxon Valdez size, occurring at the Monterey Peninsula, California, would kill at least 50% of the total California sea otter population.
In the Aleutian Islands in recent decades, the population declined to a uniformly low density in the archipelago, suggesting a common and geographically widespread cause. These data are in general agreement with the hypothesis of increased predation on sea otters (Doroff et al. 2003). Killer whales presumably shifted their diet to include sea otters after populations of their preferred prey, harbor seals (Phoca vitulina) and Steller sea lions (Eumetopias jubatus), declined.