Two otters play in water

Conservation & Research

Legal Protection

The Endangered Species Act, 1973 (ESA)

The Endangered Species Act of 1973 (ESA) is administered by the U.S. Departments of Interior and Commerce. It seeks to stop the extinction of wild animals and plants in the United States, other nations, and at sea.

Under the ESA, the neotropical, southern, marine, giant, and Congo clawless otters are listed as "endangered" (species faces a very high risk of extinction).

The California sea otter is listed as "threatened" (species faces a high risk of extinction).

IUCN/The World Conservation Union

IUCN/The World Conservation Union is a worldwide conservation organization. This organization links together government agencies, non-government agencies, and independent states to encourage a worldwide approach to conservation.

IUCN/The World Conservation Union lists the marine, giant, southern river, and sea otters are listed as "endangered" (species has a very high risk of extinction). The smooth-coated otter is listed as "vulnerable" (has a high risk of extinction), and the Eurasian and Asian small-clawed otters as "near threatened" (has a potential future risk of extinction). The Congo clawless, neotropical, and hairy-nosed otters are listed as "data deficient" (not enough data are available to determine the species' risk of extinction).

Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)

CITES is an international treaty, developed in 1973, to regulate trade in certain wildlife species.

CITES Appendix I lists species identified as endangered. The neotropical, southern, marine, giant, and California sea otters, as well as some subspecies of Eurasian otters and A.c. microdon, are listed on CITES Appendix I.

All other otter species and subspecies are listed on Appendix II, in which the species is identified as threatened.

International Fur Seal Treaty

Sea otters have been protected by the International Fur Seal Treaty since 1911. This treaty between U.S., Russia, Japan, and Great Britain was established to ban large-scale commercial hunting of sea otters and fur seals and to allow their populations to recover. Since then, sea otter numbers have increased. The California population, thought to be extinct in 1920, has grown to its current figure of about 2,800 (USFWS 2004).

Marine Mammal Protection Act of 1972 (MMPA)

The MMPA, with certain limited exemptions, makes it illegal to hunt, harm, or harass any marine mammal in U.S. waters.

The primary objective of the MMPA is to maintain the health and stability of the marine ecosystem and to obtain and maintain an optimum sustainable population of marine mammals.


Three species of otters - North American river otters, Eurasian otters, and sea otters - have been reintroduced into historical habitats, in an attempt to repopulate them. These introduction efforts have met with some success.

Reintroductions of wild-caught sea otters to southeast Alaska, British Columbia, and Washington have been successful, although efforts to reintroduce California sea otters to the Channel Islands off the coast of Southern California were not as successful.

Zoological Parks

The unique opportunity to observe and learn directly from live animals increases public awareness and appreciation of wildlife.

In the protected environment of a zoological park, scientists can examine aspects of otter biology that are difficult to study in the wild.

SeaWorld parks rescue and rehabilitate orphaned, ill, and injured otters.

Scientists from the Hubbs-SeaWorld Research Institute (HSWRI), in cooperation with other facilities and volunteers, coordinated efforts to rescue and treat sea otters affected by the 1989 oil spill. About 360 sea otters were rescued and treated at nearby rehabilitation facilities. Of these, 195 were successfully rehabilitated and released.

Scientists removed the oil from the otters' fur with dishwashing detergent. The otters then required a long rehabilitation period to regain the natural oils that protect their fur and to build up an insulating layer of air.

For ingested oil, scientists administered a treatment of activated charcoal, given orally, to bind to the hydrocarbons in the crude oil and allow them to pass through the intestine.

At the request of the U.S. Fish and Wildlife Service (USFWS), some rescued California sea otters are being monitored in long-term studies in zoological parks such as SeaWorld San Diego.

SeaWorld Orlando occasionally rescues orphaned North American river otter pups. Animal experts bottlefeed the pups, then wean them on a diet of fish before they are released.

In cooperation with the American Zoo and Aquarium Association (AZA), SeaWorld breeds Asian small-clawed otters as part of AZA's Species Survival Plan (SSP). The goal of the SSP is to preserve, in zoos and aquariums, animals that are threatened or endangered in the wild.