A member of the weasel family with dense fur, living along North Pacific coasts.
Its hind feet are webbed. Air held in its dense coat helps keep it warm in cold water.
Sea otters groom their fur to retain insulating air. Their feeding also connects them with other organisms. In a Californian estuary, experiments examined links between otters, crabs, small algae-eating animals and the amount of seagrass in underwater meadows.
In observations at Simpson Bay, Alaska, in 2008–2011, mothers with pups under four weeks old spent 9% of their time foraging, compared with 32% for mothers with pups aged eight to twelve weeks. Older pup groups rested less and spent more time eating solid food supplied by their mothers.
An Elkhorn Slough eelgrass experiment compared plots excluding otters but containing large crabs, plots excluding crabs, and plots accessible to otters. After 30 days, plots without crabs or with otter access had more algal grazers and greater eelgrass biomass.
An extinction-risk assessment has not been added yet.
Oil on the fur damages its insulation, and grooming can cause sea otters to swallow oil.
Oil damages the insulating function of sea otter fur. Alaska monitors population status and threats as part of protection and management.