Sea otters protect themselves from predators by escaping to dry land, hiding in kelp or swimming away. The main predators of sea otters are water-bound sharks and killer whales, so sea otters can protect themselves by climbing onto land.
Although sea otters must protect themselves most often from marine predators, they also have to watch out for land predators. Coyotes and bears are known land predators of sea otters. If the otters cannot escape into the water from these predators, they must use their strong teeth as a last-ditch effort.
Sea otters not only need protection from predators, but from their own environment. Their natural inclination is to spend a great deal of time in cold water. Where as some marine mammals use a thick layer of fat to keep warm, sea otters insulate themselves with a thick layer of fur. Every square inch of a sea otter's skin is covered by about one million hairs. This dense hair prevents water from reaching the skin and acts as a waterproof coat.
Sea otters are also privy to poaching and disease. For example, in the mid-1990s, a disease threatened to desolate the California sea otter population. Poaching for the animal's fur has also seriously affected the sea otter population.