Historically, sea otters used to have a much larger range which can be seen in yellow on the map. Today, they have a much smaller range with many gaps in their population, which can be seen in purple. Sea otter numbers have also continually decreased. In the early 1700's, before the fur trade became abundant there were about 150-300,000 species worldwide. But once explorers from Russia reached Alaska in about 1741, they started harvesting a large number of sea otters, almost extirpating the species throughout the range. This continued for about 150 years, and by the time the Fur Seal Treaty was signed in 1911, there were less than 2,000 individuals left in 13 small colonies. Many protections have been put in place for sea otters, which has helped their range and population increase. Despite the protections, sea otters are still nowhere near recovered and still face many threats. The exact number of sea otters today is hard to estimate, but a rough estimate between 50,000 to 100,000 animals has been given. 

Sea otters are listed as endangered, and their population is actively decreasing because of a variety of different threats. They were hunted to the brink of extinction in the 18th and 19th century, which created a population bottleneck, they still have not been able to recover. 

• Low genetic diversity is the main threat that is risking the extinction of sea otters. It is the result of the population being so low that sea otters are inbreeding. The inbreeding causes the gene pool to be extremely small, so favorable genes to improve their biological fitness are not as prevalent. 

Some other threats include:

• Illegal hunting and trapping for their fur.

• Oil spills and other pollutants.

• Toxoplasmosis and other Diseases- They acquire many infectious diseases because of contaminants in the water from pollution.

• Overfishing- This causes a depletion in their food sources, and they can get tangled in fishing gear. 

Sea otters are still under the protection of the 

• Endangered Species Act: Established to stop the extinction of wild animals and plants (since 1977).

• International Fur Seal Treaty: Established to stop large-scale commercial hunting or sea otters and fur seals (since 1911).

• U.S. Marine Mammal Protection Act: Goal is to maintain the health and stability of the marine ecosystem, while also making it illegal to hunt, harm, or harass any marine mammal in U.S. waters (since 1972).

• Canadian Species at Risk Act: Established to prevent wildlife in Canada from disappearing, to provide for their recovery, and to manage their habitat (since 2009).

• CITES: International treaty to regulate trade in certain wildlife species (since 1973).

The US Fish and Wildlife Service is the federal agency responsible for their conservation and management. The IUCN also lists many different conservation actions in place:

Research and monitoring: Action recovery plan and systematic monitoring scheme.

Species management: Harvest management plan, successfully reintroduced, and ex-situ conservation.

Water and Land protection: Conservation sites established over their entire range, species occur in at least one protected area, and area based regional management plan. 

Education: Education and awareness programs, species included in international legislation, international management/trade controls for species.

Many organizations also strive to protect sea otters:

• Coastal Conservancy: California Sea Otter Fund 

• Sea Otter Foundation

• Monterey Bay Aquarium

• Friends of the Sea Otter

• Seattle Aquarium

With the lack of biodiversity in our ecosystems, protecting and conserving ALL endangered species is essential, but sea otter's are especially important for many reasons:

• They have some of the lowest genetic diversity out of any species, which makes them more susceptible to extinction. 

• Sea otters are a keystone species, so without them the ecosystem would lack balance which could have catastrophic effects. 

• They help keep kelp and sea grass healthy, while also maintaining the sea urchin population. 

• They help fight climate change: Sea otters help ecosystems capture carbon from the atmosphere and store it as biomass and detritus, preventing it from being converted back to carbon dioxide and contributing to climate change.