The Sea Otter is a member of the weasel family. Female sea otters weigh about 45 pounds and males are usually 60 pounds when fully grown. Some Northern sea otters are weigh as much as 100 pounds! They can be as long as 4 feet and have a thick layer of soft fur. Unlike many other water-mammals, sea otters do not have a layer of blubber fat to stay warm. It must depend only on its fur for protection. The sea otter has flat hind feet that look like flippers and a long flat tail to help propel it through the water.

Sea otters live in the coastal waters of the northern Pacific ocean, from northern Japan to Alaska and down the coast of California. These areas have the rocky shores and dense kelp plants that sea otters like. They eat mussels, clams, oysters, crabs and snails. Sea otters are the only animals besides primates (great apes and humans) that use tools: sea otter use small rocks that they sharpen to pull food from shells and rocks. A sea otter can dive as deep as 330 feet while looking for food! It stores its food in a loose flap of skin next to each front leg.

Sea otters live in groups called pods. Each pod has between 50 to 100 animals and often stays in the same area for many years. Male and female sea otters tend to separate, but do not mark territory or act aggressively. Sea otters mate about once a year from the time they are 4 years old. A female sea otter carries her young for about 8 to 9 months and then gives birth to live offspring in the early spring. She feeds and cares for them for 8 months, grooming and teaching them. After this time, the pup may stay with the pod or join another group.

The sea otter has been heavily hunted by humans for hundreds of years. Its warm, thick fur is especially prized for coats. It is still very much in danger, despite laws that protect its territory and forbid its capture. Sea otters are also very vulnerable to oil spills: the sticky oil can coat their fur and without the blubber to protect them otters may die of cold and exposure to bad weather.