
Sea Otters 101
It is estimated that the worldwide population of sea otters once numbered between several hundred thousand to over one million before being nearly hunted to extinction by fur traders in the early 1700s and 1800s. At that point, there were only 1,000 – 2,000 sea otters left in the wild. Sea otters finally gained protections with the signing of the International Fur Seal Treaty of 1911. Worldwide numbers have slowly recovered but still stand far below original population numbers.
Why They’re Important
Sea otters are what are known as a keystone species, meaning their role in the environment has a greater effect than other species in that environment. As predators, sea otters are critical to maintaining the balance of the near-shore kelp ecosystems.
Sea otters mainly eat urchins, abalone, mussels, clams, crabs, snails and about 40 other marine species. Without sea otters, these undersea animals would devour the kelp forests off the coast that provide cover and food for many other marine animals.
Major Threats
Currently the largest human threats to sea otter populations are entrapment in fishing traps and nets, shootings, and oil spills. The latter causes their fur to mat preventing it from insulating their bodies in the frigid water, resulting in death from hypothermia. Indirect threats include pollution from runoff into the marine environment and habitat degradation. The pollution of our coasts has resulted in sea otters being the most diseased wildlife populations in the world.
What Defenders Is Doing to Help Sea Otters
Defenders of Wildlife has been a strong leader in the recovery efforts of the California and Alaska sea otter.
In California, Defenders has championed the voluntary tax check-off program, which is a program for state residents to provide funds for sea otter research and law enforcement efforts. Defenders also mobilized our supporters to end a failed translocation program, resulting in more than 11,600 comments being sent to the U.S. Fish and Wildlife Service supporting a repeal of the no-otter zone.
In Alaska, Defenders continues to monitor any sea otter-related issues in the state. Our staff are trained and certified as sea otter rescue and rehabilitation volunteers and are members of the Alaskan Marine Mammal Stranding network.




