The California, or southern, sea otter (Enhydra lutris nereis) is the only sea otter subspecies currently listed as an endangered species under the federal Endangered Species Act. The California sea otter is also a "fully protected mammal" by California state law and by the Marine Mammal Protection Act.
             In the 1700's, the sea otters were hunted to near extinction for their fur. In the late 1930's, a small population of otters (estimated at approximately 300) was discovered along California's Big Sur coast. The California population is estimated at a mere 2,000 as of Fall 2001.
             Historically, there were between 16,000 to 20,000 sea otters along the coast of California
             Sea otters are classified as both an umbrella species, and a keystone species. As an umbrella species, the protections made for the sea otter will essentially affect a large number of other species in their ecosystem. A keystone species is a term used to refer to the sea otters functional role within their ecosystem. The feeding habits of the sea otters have a crucial effect on their ecological system, and their actions affect many of the organisms within their food chain. The sea otters can be referred to as indicators of the health of their ecosystem.
             Many causes have been recognized as contributing to the population decline: shark attacks, gunshot wounds, mating activities, fishing/net line injuries, habitat degradation, lack of an adequate food supply, land and water pollution, and disease. In a 1996 report, nearly 1700 sea otter deaths had been documented. The report stated that 18.9% of the deaths were from some sort of trauma, 12% from shark attacks, 4.6% from gunshot wounds, 2.3% from mating activities, 4.6% from fishing/net line injuries, 16.5% due to dependent animals, 4% from natural causes, and 56% of the deaths were undetermined.
             From 1992 to 1995 the National Wildlife Heath Center had examined approximately 5
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