Sea Otter Adaptations

The sea otter is a large member of the weasel family that spends almost its entire life in the water. It lives in the coastal waters of the Pacific, ranging along the U.S. coast to Asia. Fur hunting almost wiped the species out in the early 20th century, but it is now protected and slowly coming back.

  1. Physical Adaptations

    • The sea otter has a number of physical adaptations that help it live its aquatic life. Unlike many aquatic mammals, the otter does not have fat deposits to keep it warm in cold water. It instead has a thick, double layer waterproof coat to keep out the cold. The animal's rear legs are long, with broad webbed feet. These, along with the tail and front legs help propel the otter through the water. The otter is capable of closing both its ears and nostrils to keep out water when diving. A high metabolism also helps to keep the otter warm.

    Behavioral Adaptations

    • Sea otters prefer to stay in the water but will rest on land if there are too many otters in the area. The animal hunts underwater, using both sight and touch to locate shellfish, squid, sea urchins and fish. To help conserve heat when the otters float on their backs, they keep their feet out of the water to minimize heat loss. Fastidious cleaning after meals keeps the animals' important insulating coat in good condition. When sleeping, the otters avoid drifting out to sea by wrapping themselves in floating kelp. Sea otters have adapted to giving birth in the water with the mother carrying the young on her stomach while swimming on her back.

    Using Tools

    • Other than humans and a few other animals, using tools is rare in the animal kingdom. Sea otters are one of the species that actively use tools. Small stones or rocks are used to break open the shells of crustaceans and shellfish. While floating on its back, the otter rests the shellfish on its stomach and uses its front paws to smash the rock against the shell until it breaks.

    Defensive Adaptations

    • The sea otter stays safe from land predators by being almost fully aquatic. Other than its size, the animal has no specialized defense techniques against the predators of the sea, such as the killer whale. Vigilance while swimming and agile avoidance are the only way the otter can stay safe. This alertness does not protect it from humans and is a main reason that the sea otter almost became extinct.