Southern sea otter

Enhydra lutris

Once living along the entire west coast of North America, sea otters were nearly hunted to extinction for their thick fur. Now small populations exist in Alaska, Canada, California and Washington.

There are three subspecies:

  • Russian sea otters live in the Kuril Islands and the east coast of the Kamchatka Peninsula north to the Commander Islands.
  • Northern sea otters (Alaskan) inhabit the Aleutian Islands to Prince William Sound and southward to Washington.
  • Southern sea otters (California) inhabit the central California coast. Historically, they ranged from northern to Baja California.

Did you know?

  • At one time, both northern and southern otters inhabited the Oregon coast.
  • Sea otters are a keystone species. This means their presence or absence has a huge impact on their environment. In their marine habitat, sea otters control populations of species such as sea urchins. Without otters, sea urchins have proliferated, destroying kelp beds that are home for many types of sea life.
  • Most marine mammals have a thick layer of fat under their skin to keep them warm. Sea otters don't have this; they rely on a high metabolism and dense fur to keep them warm. Otters' dense coat traps air close to their bodies, creating an insulating layer of air pockets. Their coats contain more than 1 million hairs per square inch in places, making it the mammal with the densest fur.

Sea otter behavior and facts

  • Sea otters eat clams, crabs, urchins, snails, octopus, mussels and sea stars. They may eat fish. Individuals seem to develop food preferences from their mothers.
  • They have semi-retractable claws, agile paws and webbed hind feet that are flattened into broad flippers. They are the only carnivores with four incisor teeth in the lower jaw.
  • Sea otters are diurnal (active during the day). They sleep at night in kelp beds, where they wrap themselves in kelp to keep from drifting.
  • Sea otters do not migrate, but may travel 20 to 250 miles any time of year.
  • They are playful and intelligent. They use rocks or other hard objects to pry or break open urchins, abalone or other shellfish.
  • As they age, they can become golden-colored.

From birth to death

  • Gestation: average 6.5 months
  • Sea otters generally have one pup per litter
  • At birth, a pup weighs 3 to 5 pounds
  • Northern sea otters give birth on land; southern sea otters may give birth at sea.
  • Light fur with guard hairs keep pups afloat; it's replaced by sleek dark fur at about 3 months. They are born with open eyes and a full set of milk teeth.
  • Pups depend on their parent for 11 months.
  • Sexual maturity: 3 to 5 years
  • Lifespan: 10 to 20 years in the wild, slightly longer in captivity.

Vital statistics

  • Length: 3 to 5 feet, including a 22 to 33 inch long tail.
  • Weight:
    Males: 60 to 70 pounds
    Females: 35 to 64 pounds


Sea otters are classified as a threatened species in the United States and are listed under CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) App I. The southern sea otter range is slowly expanding, while a portion of the northern sea otter populations are decreasing.

Sea otters, the Oregon Zoo and you

The Oregon Zoo's southern sea otters live in the Steller Cove exhibit. Each day, they eat clams, crabs, shrimp, urchins, mussels, squid and fish.

Sea otters are vulnerable to pollution that runs off the land into rivers and then to the ocean. You can help otters return to Oregon by:

  • Fertilizing your garden with nontoxic or biodegradable products.
  • Buying local or organic food produced with fewer pesticides and less gasoline.
  • Buying only sustainably harvested seafood.
  • Reducing runoff from oil products by riding a bike, walking or taking the bus or MAX.
  • Fixing oil leaks in your vehicles and disposing of the oil (along with paint and other hazardous liquids) at a hazardous waste facility.

Sea Otters at the Oregon Zoo




Thelma is a female southern sea otter. She was born in 1998. She was found abandoned as a pup. Thelma arrived at the Oregon Zoo on June 2, 2000 from the Monterey Bay Aquarium in California. She is on long-term loan from the U.S. Fish and Wildlife Service. She was released twice, but didn't forage well on her own...