Resource Benefits and Conflicts of Sharing a Coast with Sea Otters

Sea otter eating clam.

Check with the next sea otter you see bashing a shell on its chest. Chances are good that he’s going after a meal we humans enjoy as well. Abalone, clams, crabs—they all can make the otter menu. Though we might marvel at the ingenuity it takes to find 25 percent of their bodyweight in food every day, it’s also easy to see why sea otters are seen as competing with fishers: the shellfish in an otter’s paws may seem like one fewer for fishers to catch. But many of the shellfish otters can catch and pry from between rocks at great depths are not really available to fishers. The reality is far more complicated, with otters actually pulling their own weight when it comes to the economy.

Yes, otters do eat a lot. They are wily hunters, and when people and otters start harvesting shellfish from the same spot, it’s usually only a matter of time before there are few very large shellfish left to catch. That creates problems for the otters that have to figure out something else to dine on and for people who depend on income from fishing.

Most shellfish fisheries along California’s central coast gained traction around 1900, when the population of sea otters was at an all-time low. For much of the 20th century, otters weren’t numerous enough to pose much competition. Some scientists argue that people had been taking too many shellfish even before sea otter numbers started to rebound, and that mismanagement, not competition with otters, has continued to make harvests more difficult and less profitable. Very significantly, diseases and parasites, likely introduced in ballast water or by aquaculture, have destroyed most of the black ablone population south of Big Creek and have badly damaged other abalone species. But as the otter has clawed its way back from the verge of extinction, it became an easy scapegoat.

In 1987 the U.S. Fish and Wildlife Service created an “otter-free zone” south of Point Conception on the California Coast in the hopes of protecting  shellfish harvests. As silly as it may now sound, the law required that any and every otter that ventured into the no-otter-zone had to be captured and then relocated northward along the coast.  Obviously these relocation efforts and the imaginary line that determined the northern border of the no-otter-zone did very little in preventing the otters return.  The program was finally deemed a failure, and the U.S. Fish and Wildlife Service is currently in the process of shutting down the costly program. Interestingly, U.S. Representative Elton Gallegly has presented a bill to Congress, that some say, if passed, would prolong the termination of this relocation program.  And it would require the USFWS come up with a plan that would simultaneously assure the recovery of threatened sea otters, white abalone and black abalone. Another impossible task.

Recent research shows that sea otters are in fact an important part of California’s economy. A study at Colorado State University estimated that as sea otters expand their range southward, they’ll bring $100 million to the California economy. But how? Increased revenue from tourism and recreation, for one. Protecting otters indirectly protects the places we humans enjoy. Places like California have banned oil and gas drilling along the coast, in part because an oil spill would be catastrophic to the otter population, though rising gas prices have increased the pressure on lawmakers to ease the drilling ban. These protections translate into millions more tourism dollars from visitors who might be as  interested in seeing otters as in boating or recreational fishing. . Another study values each individual otter at a half a million dollars to the state’s economy.

More economic benefits come in the form of what scientists call “ecosystem services.” In other words, otters are vital to maintaining healthy kelp forests. As a keystone species, otters are just as valuable below the surface of the ocean. Kelp harvesting in California is worth as much as $40 million, but without otters to keep their numbers down, sea urchins mow down vast swaths of kelp forest. These “urchin barrens” also can’t support the myriad animals and plants including seals, fish, and even shellfish that thrive in the protective kelp forest environment. Kelp forests help protect shorelines from storm surge and also absorb massive amounts of carbon dioxide acting as a  powerful carbon sink. So, as strange as it might sound, a healthy otter population might be just the trick to helping nearshore ecosystems and their fish and shellfish bounce back.

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About is dedicated to raising awareness about California's threatened sea otters and the role research plays in the species recovery and conservation. It's a collaboration of the Monterey Bay Aquarium, U.C. Santa Cruz, U.C. Davis, U.S. Geological Survey, U.S. Fish & Wildlife Service, California Department of Fish and Wildlife, among others. is also home of the world's first HD live stream of southern sea otters in the wild.