A walrus eats mainly mollusks, such as clams. A walrus also eats shrimp, crab, worms, sea cucumbers and coral. Occasionally, a walrus has been known to eat the carcasses of seals when it cannot find food.
Because of their extremely large size, walruses eat a great deal of food. Adults commonly consume 3,000 to 6,000 clams in a single feeding. Walruses usually stay close to the shore when searching for food, but they can dive over 200 feet to find their meal. They can stay underwater for about 30 minutes at a time before they need to come up for air.