The heaviest members of the weasel family, sea otters are also the second smallest marine mammals. Historically, sea otters numbered between several hundred thousand to more than a million. But due to the fur trade, worldwide numbers plummeted down to a total of 1,000-2,000 in the early 1900s. Today, there are estimated to be just over 106,000 worldwide, with just under 3,000 in California.
Scientific name: Enhydra lutris
Lifespan: 15 to 20 years
Habitat: Shallow coastal waters of the northern Pacific
Range: Sea otters can be found in Siberia, Japan, Alaska, British Columbia, Oregon, Washington, California and through the Aleutian Chain.
Diet: Urchins, abalone, mussels, clams, crabs, snails and more.
Unlike other marine mammals, sea otters do not have a layer of blubber to help them keep warm. Instead, sea otters have the densest fur in the animal kingdom, ranging from 250,000 to a million hairs per square inch, which insulates them.
Sea otters are a keystone species, meaning their role in their environment has a greater effect than other species. As predators, sea otters are critical to maintaining the balance of the near-shore kelp ecosystems. Without sea otters, the undersea animals they prey on would devour the kelp forests off the coast that provide cover and food for many other marine animals. Additionally, sea otters indirectly help to reduce levels of atmospheric carbon dioxide, a prevalent greenhouse gas, as kelp forests play an important role in capturing carbon in coastal ecosystems