Sea otters are marine mammals that live in the shallow coastal waters of the North Pacific Ocean. Beginning in the mid-1700s, sea otters were exhaustively hunted for their pelts; by the early 20^th century, the worldwide sea otter population was fewer than 2,000, and they were near extinction. However, the population has significantly rebounded since the 1911 International Fur Seal Treaty among the United States, Russia, Japan, and Great Britain banned the trade of sea otter fur, and sea otters were reintroduced into areas of depleted populations.

Alaska Native peoples can still hunt sea otters for subsistence purposes and for use in Native handicrafts or clothing. Although hunting is limited so as not to be wasteful, there is no harvest limit. In an effort to conserve and manage sea otters, Alaska Native hunters report data on their harvests and local Alaskans and biologists collect data from sea otter carcasses found on beaches.

While sea otter populations remain stable in some areas, they are increasing or decreasing in other regions. Managing sea otters requires an understanding of how the sea otter fits into its marine ecosystem. Otters do not migrate unless their home range, which typically spans a few tens of kilometers of coastline, becomes overpopulated or the food supply is depleted. The otter's high metabolism and lack of an insulating layer of fatty tissue (found in many other marine mammals) require it to eat large quantities of food: a sea otter consumes up to one-third of its body weight daily. Sea otters eat a variety of marine species, including clams, crabs, fish, mussels, and urchins, and they must compete with subsistence and commercial users of these resources.

Loss of food resources, pollution, disease, and predation are now the primary threats to sea otters. The Exxon Valdez oil spill in 1989 is estimated to have killed thousands of sea otters; oil coats the otter fur, reducing its insulating value and causing hypothermia. In addition, sea otters are high on the food chain and can develop high levels of pollutants obtained from their prey. There has been an increase in sea otter mortality because of bacterial infections in Kachemak Bay; it is suspected that the otters are acquiring the bacteria through their diet. Some biologists believe that killer whales are responsible for the dramatic decline in the number of sea otters in the Aleutian Islands; they suspect killer whales are feeding on sea otters instead of their usual prey, seals and sea lions, whose populations are depleted by loss of their own primary food sources.

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