Sea otters are a unique species in their ecosystems because the health of the ecosystems can be gauged by the health of the sea otters that live there. They are what is called a keystone species. If sea otters are thriving, so are the habitats they call home. So not only are sea otters one of the most adorable creatures, but they are also very important. But where do sea otters live? Do they spend all their time at sea? And how do they stay warm in waters that other marine mammals need blubber to survive in?
Where Do Sea Otters Live?
Sea otters live in shallow coastal waters in the northern Pacific Ocean. Sea otters can be found off the coasts of Japan, Russia, the Aleutian Islands, southern Alaska, British Columbia, Washington State, and California. They live, swim, and feed in estuaries, kelp forests, and embayments. They spend most of their time in the water, swimming, floating on their backs, and diving for food. They are clumsy on land but may occasionally “haul out” to avoid predators or to warm up. While they are less graceful on land, sea otters are stellar swimmers with webbed hind feet to help them dive for prey.
The Three Kinds of Sea Otters
There are three species of sea otter, the Russian sea otter, the northern sea otter, and the southern sea otter. Russian sea otters are found off the coasts of Russia and Japan. Northern sea otters are found in southern Alaska, the Aleutian Islands, British Colombia, and Washington. Finally, southern sea otters are found off the central coast of California.
Stern sea otters are about 4 feet long and weigh between 50-70 pounds. Northern sea otters are a bit bigger and can get up to 5 feet long and weigh between 70-100 pounds.
What do Sea Otters Eat?
Sea otters are fully aquatic and eat a variety of sea creatures. Most sea otters will eat crabs, snails, urchins, mussels, clams, and other marine invertebrates. Northern sea otters will additionally eat fish. Sea otters will dive for food and then surface and float on their backs using their stomachs as a table. They will use rocks to break open mussels and clams. Sea otters also have “pockets”. These loose flaps of skin allow them to stash food during a dive so that both their front paws are free to keep hunting.
How do Sea Otters Survive the Cold?
Sea otters do not have blubber like most marine mammals do. So how do they stay warm? Turns out that sea otters have some of the densest fur of any animal. Just one square inch of fur has more than a million hairs. For compassion, humans have 100,000 or fewer hairs covering their entire heads. Sea otters have a dense, double coat and have natural oils they groom with to ensure that their coats stay waterproof. Their high metabolism also helps keep them warm since they eat a quarter of their own every day. Like birds, sea otters can fluff their fur to create air pockets that serve as insulation. Sea otters spend hours every day on fur upkeep so that they can safely survive cold northern waters.
What are a Sea Otter’s Natural Predators?
Sea otters have a lot of natural predators, including avian (sky), terrestrial (land), and pelagic (ocean). Some of the most common predators of sea otters include killer whales, white sharks, bald eagles, brown bears, wolves, coyotes, and sea lions. Sea otters also used to be hunted by humans for their thick furs, but laws have since been put in place to protect this keystone species.
Baby Sea Otters
Sea otters only give birth to one pup at a time. If two are born at once, the mother is forced to abandon one since she can only care for one at a time. Pups can be born anytime, as sea otters do not have a pupping season and breed year-round. Males do not contribute to raising the pup at all. Males mostly live in groups called rafts that can contain anywhere from 60-100 individuals. Once a pup is born, they are taken care of by their mother for 2-3 months. Mothers will fluff their baby’s fur, making them virtually unsinkable. Pups bob on the water's surface while their mother dives and hunts. Once pups lose their baby fur, they will learn how to dive and hunt by following their mothers on hunts. Sea otters can live between 10-20 years.
Despite being a protected species now, sea otters are still an endangered species. These fuzzy creatures play a significant role in nearshore ecosystems, and as such, it is important to continue efforts to preserve their habitats so they can survive.
Sea otters are knowns as the “old man of the sea,” and aptly so, as they serenely float on their backs, cracking clams on their stomachs, and peacefully living life at their own pace.