Food and Feeding
Sea otters rarely venture more than one mile off shore. Instead they live in small herds in shallow waters, particularly around kelp beds, great forests of seaweed, rich in shellfish, fish and other marine life. They play an important role in the kelp beds, as they are the only mammals to eat sea urchins, which are voracious feeders on the kelp.
The kelp is also useful to sea otters when they sleep at sea, as they wrap it around themselves to prevent drifting. Some individual sea otters prefer to come ashore to sleep though, possibly as protection against killer whales.
They are active by day and feed, float, sleep and swim on their backs, only swimming belly-down when in a hurry or trying to evade predators. Feeding takes place mainly in the early morning and evening, with sea urchins, crabs, abalones and other shellfish being the main items on the menu, although fish and octopus are also eaten occasionally. Sea otters regularly dive to depths of 100 feet in search of food and stay under for 30-40 seconds, although they are capable of diving up to 300 feet, and of holding their breath for up to five minutes in an emergency.
When eating, the chest is used as a table. Large crabs are eaten piecemeal, one leg at a time, while the crab runs about on the sea otter's chest. The sea otter is one of a very small group of animals (such as the chimpanzee, orangutan, Galapagos woodpecker finch, Egyptian vulture and human) that use tools. A flat stone is often placed on the chest and used by the otter as an anvil on which the shells of mussels and other shellfish can be smashed by repeatedly dashing them against the stone using the forepaws. Sea otters have to eat one-quarter of their own body weight (up to 25lbs) per day in food to survive.
Read More: Breeding