Sea Otters

While sea otters fascinate, even enchant people with their cute faces and amusing antics, they are a remarkable and extremely specialized aquatic animal. Southern sea otters inhabit the giant kelp forests growing just offshore along the California coast, while two other sea otter subspecies live in the kelp beds of southern Alaska and northeastern Asia. Scientists estimate that these otters once numbered between 150,000 and 300,000 animals, but commercial hunting of sea otters for their wonderful fur during the 18th and 19th centuries nearly drove them to extinction.

Around 1900 only 1,000 or 2,000 sea otters had survived. In California the southern sea otter was believed extinct. Then in 1915, scientists found an isolated colony of about 50 otters in Bixby Creek Cove on the Big Sur coast. They managed to keep their find a secret until after the coast highway opened through Big Sur. In 1938 the public became aware of the remnant population, and people’s fascination with sea otters has been growing ever since. All of today’s estimated 1,500 to 2,000 California sea otters descended from those 50 individuals. The northern populations have rebounded more quickly to around 150,000 animals.

California’s sea otters range from Año Nuevo in San Mateo County to Avila Beach in San Luis Obispo County, with the highest concentration between Santa Cruz and southern Big Sur. They are considered “threatened” under the Endangered Species Act and are a “fully protected mammal” under California law.

Adult sea otters are about four feet long and weigh between 40 and 80 pounds. They use their webbed hind feet as flippers for swimming, but use their unwebbed short front paws for feeding and grooming. In fact otters use stones as tools, prying shellfish loose from underwater rocks, then breaking the shells while floating on their backs on the surface. Otters spend much of their time grooming because their dense fur is invaluable, both for buoyancy and warmth. Unlike all other marine mammals, otters have little blubber to insulate them from chilly ocean temperatures. Because of this an otter must consume about 25 percent of its body weight each day, 2½ tons of food each year. The sea otter’s thick fur is the densest animal fur on earth, with up to a million hairs per square inch.

The sea otter is the second smallest of the marine mammals, also the slowest swimmer and least streamlined member of that group. Sea otters were also the last group of marine mammals to leave land for the ocean. Scientists believe their ancestors turned to the sea five to seven million years ago, gradually adapting to ocean life. Sea otters are one of the largest members of the mustelid family, which also includes river otters, weasels, skunks, minks and badgers. Sea otters usually swim belly-up on their backs while river otters, which are no more than half as large and will sometimes enter the ocean, swim belly down.

Spotting sea otters can be tricky because the kelp floats of the kelp beds they favor resemble otter heads, but by observing carefully, especially with binoculars, you’ll eventually pick out the often light colored head of the sea otter along with the upturned belly and outstretched forepaws. They’ll frequently entertain you with their antics, preening, yawning, rolling or even cracking open a shellfish dinner with a rock held in their agile paws. If you should find a dead, sick or wounded otter on shore, never touch the animal but immediately notify the California Department of Fish and Game.