Hunted to near extinction in the 18th and 19th centuries, sea otters finally gained protections with the signing of the International Fur Seal Treaty of 1911. In the 1970s, they received additional safeguarding under the Marine Mammal Protection Act and the Endangered Species Act. Worldwide, sea otters have slowly recovered but still stand far below their historical population numbers. While sea otters are vulnerable to natural environmental changes, their populations are significantly impacted by several human factors as well.

Sea otters are a keystone species, meaning their role in their environment has a greater effect than other species. As top predators, sea otters are critical to maintaining the balance of nearshore ecosystems, such as kelp forests, embayments and estuaries. Without sea otters, sea urchins can overpopulate the sea floor and devour the kelp forests that provide cover and food for many other marine animals. By maintaining healthy kelp forests, sea otters also indirectly help to reduce levels of atmospheric carbon dioxide, a prevalent greenhouse gas, as kelp absorbs and sequesters carbon.

Defenders' Impact

In 2006, Defenders of Wildlife worked with California lawmakers on legislation that established the California Sea Otter Fund, a voluntary contribution option on the state tax forms. The fund pays for important scientific research, public education and law enforcement that benefits sea otters.

Defenders helped pass a state law that mandated warning signs on containers of “flushable” kitty litter. This became necessary when researchers discovered that a protozoal parasite from flushed cat feces, Toxoplasma gondii, could pass through wastewater treatment facilities and harm sea otters.

We also worked to end to the translocation program, which moved sea otters to San Nicolas Island, and the associated No-Otter Zone.

We supported a bill to phase out the use of drift gillnets in California waters to protect sea otters and many other marine species.

To protect sea otters that were crossing roads in Moss Landing, CA, Defenders helped make the case for placing crossing signs and establishing slow speed zones, and we worked with local sea otter protection organizations to install wildlife monitoring cameras.

Finally, we are working with state and federal agencies and other groups to maintain, increase and broaden the current protections for sea otters so they can expand their population along more of California’s coastal waters.