Endangered Species Report #37
Sea Otter

Written by: Holly L. Koppel

The sea otter, poster species for endangered species during the Exxon-Valdez oil spill, is still in trouble, but now it is because of disinterest and political budget cuts. Over time this species has been threatened by fur traders, fisherman, and oil spills, and each time the sea otters have made a small comeback. Unfortunately, just as the species was recovering from the 1989 oil spill, sea otters started to die off in record numbers for no obvious reason. This comes at a very troubling time as the sea otter population in California is close to being taken off the endangered species list. The U.S. Fish and Wildlife Service is currently in the process of researching what the cause of these sea otter deaths is; however, repeated budget cuts has made this research almost impossible.

There are three subspecies of the sea otter, the most well known being the California or southern sea otter. The other two types are the Alaskan and Russian. Historically, sea otters could be found in the Hokkaido Island of Japan, north through the Kuri Islands, to the southern coast of Alaska, and west coast of North America to Mexico. Now they can only be found through the Aleutian Islands, southern Alaska, and parts of southern North America. These animals spend most of their life in the water, so water quality is especially important to maintain for a healthy population. So far, studies have shown that toxic chemicals dumped into the ocean by large corporations has had a negative impact on the sea otter population.

Sea otters have also been called one of the world's cutest endangered species, making them an obvious choice for posters decrying the death of over 5,000 otters in the Exxon-Valdez oil spill. Because the otter's fur is so dense (100,000 furs per centimeter), oil is easily trapped, making it almost impossible for the otter to get it out.

Sea otters are also the only one of the otter species to have retractable claws. This allows them to be able to catch their prey as they swim. The main diet for the sea otter includes sea urchins, mussels, snails, crabs, squid, and sea stars. The otters must consume 20-25% of their body weight each day to survive. To put this in perspective, this means that the males must eat 20-25% of 65 lbs (13-16lbs), and the females 20-25% of 45 lbs (9-11lbs).

Despite the threats sea otters have faced, with the proper protection, the species can, and has in some respects, make a comeback. Unlike other species that have a set mating season, the sea otters can reproduce any time during the year. The female sea otter is sexually mature at four years, and the males are mature at five or six years. There are certain times of the year when there is a "peak" of births, usually May-June in the Aleutin Islands, and January-March for the California population. The gestation period for sea otters is generally 4-12 months, and usually only one pup is born at a time, though twin births have been reported. The pups will stay with their mothers for about five to six months, at which time they will break off on their own, and form their own territories. Sea otters have been shown to be solitary creatures, though sometimes they will come together in groups to play, and for mating.

The future does look promising for the survival of this species, and the California sea otters have reached about 2,200 individuals. Once they reach 2,650 for three consecutive years, the U.S. Fish and Wildlife Service will be able to downlist them from endangered to threatened. The only problem is that the cause of the recent rash of sea otter deaths is still undetermined, and many environmentalists believe another disaster such as the Exxon-Valdez could eliminate the remaining population. To be able to adequately protect this species as it makes its recovery, funding for the study by the U.S. Fish and Wildlife service must be found within the federal government, and we must do what we can to see that future oil spills are not as devastating as the last one in 1989 was.


Animal Diversity: Sea Otter Narrative
Friends of the Sea Otter
Monterey Bay Aquarium: Focus on Sea Otters
Help Save the Sea Otters!
Defenders of Wildlife: Conserving the Sea Otters
Sea Otter Campaign
U.S. Fish & Wildlife Sea Otter Home