The sea otter’s historic range stretched from Japan, along the coast of Siberia and the Aleutian Chain and down the Alaska, British Columbia, Washington, Oregon and California coast to Baja California. It is estimated that between 500,000 to 1 million sea otters were killed by hunters and trappers over a 170-year period, between 1742 and 1911, before protections were enacted with the International Fur Seal Treaty of 1911. At that time, wild sea otter populations had dropped to between 1,000-2,000 worldwide.

Sea otter numbers have slowly recovered since then and are estimated to be between 82,000 and 95,000 worldwide. Though greatly reduced in numbers, sea otters are still found throughout most of their historical range including Japan, Russia and the west coast of North America. 70% - 80% of all wild sea otters are currently found in Alaskan waters.

Key Recovery Milestones

Sea otter populations in the United States have been protected under the Marine Mammal Protection Act since 1972. California sea otters, also known as the southern sea otter, were listed as “threatened” under the Endangered Species Act (ESA) in 1977 and remain at that status today.

In 2005 the southwest stock of northern sea otters in Alaska were also listed as “threatened” under the ESA. In Washington state sea otters are listed as “state endangered.” The Committee on the Status of Endangered Wildlife in Canada classifies sea otters in British Columbia as Threatened.