Seals, sea lions and walrus are in the taxonomic suborder Pinnipedia in the order Carnivora, which also includes bears, dogs, raccoons, and weasels (including otters). Three families of living pinnipeds are recognized: the Phocidae (earless or true seals); the Otaridae (eared seals); and the Odobenidae (walrus). The word pinnipedia translates from Latin as "fin foot," referring to the animals’ fin-like flippers.

All pinnipeds must come ashore to breed, give birth and nurse their young. Some species are at sea for several months at a time, while others return to the shore every day. Phocid seals include elephant and harbor seals. The otariids, fur seals and sea lions, have external ear flaps, which is why they’re called "eared seals."

Under the Marine Mammal Protection Act, NOAA Fisheries Service has jurisdiction over seals and sea lions. Walrus are under the authority of the U.S. Fish and Wildlife Service. Check that agency's Web site for information on walrus.