The fur trade depleted sea otters to about 1000-2000 individuals worldwide by 1911 when the International Fur Seal Treaty between the U.S., Russia, Japan, and Great Britain was established. The U.S. Marine Mammal Protection Act in 1972 provided more support for sea otters. Reintroduction along the west coast of North America and protection from hunting has brought the world population up to 100,000-150,000. The population of California sea otters (Enhydra lutris nereis) is listed as threatened under the Endangered Species Act and will remain so until a population of 2650 is recorded for three consecutive years. The current population is about 2200. There are concerns that a single oil spill could wipe out the California sea otter. In 1989, the Exxon Valdez flooded Prince William Sound, Alaska with oil. An estimated 5,000 sea otters were killed as a result. E.l. nereis is listed in appendix 1 of CITES, the other subspecies are in appendix 2. The IUCN lists Enhydra lutris as endangered.

(Cohn 1998; Nowak 1999; Hilton-Taylor 2000)

US Federal List: threatened

CITES: appendix i

IUCN Red List of Threatened Species: endangered