Sea otters are on the endangered species list and are restless, playful mammals that have stocky legs, a thick fur, a long body, and a broad muzzle with sensitive whiskers. They are perfectly adapted to a semi-aquatic life. Their webbed feet and long, muscular tail enable them to swim comfortably. They will dive to catch small fish or to avoid danger. Otters can see as well under water as they can above it, allowing them to hunt for fish. Otters are one of the few animals known to use tools such as using small rocks to open shellfish. The sea otter must consume between 25 and 40 percent of its body weight daily, just to keep warm. They gorge on more than 100 different prey species.
Sea otters do not migrate far. Their rafts, usually comprised of a single sex, can range from as few as 10 individuals to as high as 1,000. To keep from drifting apart while they sleep, sea otters often sleep holding paws.
Sea otters once numbered in the hundreds of thousands and were common throughout the North Pacific. For thousands of years, the native people of Kamchatka hunted them for both food and fur. Sea otter pelts were valued for their rich and luxuriant fur, which has nearly one million hairs per square inch, the thickest fur of any mammal. The trade was dominated by Russian, American, and British hunters, who brought sea otter furs to China, where the soft fur was highly prized for clothing, coats, and trim. As demand for sea otter pelts increased, so did the prices and they became known as “soft gold.”
The sea otter has a historic range that forms an arc across the North Pacific Ocean, stretching from the shores of Baja California up the west coast to Alaska and across the Bering Strait to the Kamchatka Peninsula and down to the islands of northern Japan. Southern sea otters, sometimes referred to as California sea otters, make up a subspecies of sea otters that lives along the Southern Region of the California Coast. Sea otters were listed as a threatened species in 1977 under the Endangered Species Act and are protected under the Marine Mammal Protection Act.
The sea otter is considered a keystone species, one that has a disproportionately large affect on its environment relative to its abundance. Sea otters feed on sea urchins, playing a critical role in maintaining the health of kelp forest ecosystems. They also consume filter-feeding benthic invertebrates, resulting in the removal of contaminants and disease-causing pathogens from near-shore waters. Sea otters are highly effective sentinels of the health of our ocean, making their recovery an important goal of The
Marine Mammal Center.