Sea otters helped restore California kelp forests

Where sea otters were absent, kelp forests declined

As California’s sea otter population rebounded from the brink of extinction, the state’s kelp forests increased alongside them.

In a study published in PLOS Climate, researchers documented a significant increase in kelp forest canopy along California’s Central Coast over the past century. That was the only region where southern sea otters (Enhydra nereis) survived after being hunted nearly to extinction for their fur. Researchers found that the species’ impact on these kelp forests nearly compensated for kelp losses elsewhere in the state. 

“Our study showed that kelp forests are more extensive and resilient to climate change where sea otters have reoccupied the California coastline during the last century,” said lead author Teri Nicholson, senior research biologist with the Monterey Bay Aquarium Sea Otter Program.  

“Where sea otters are absent, kelp forests have declined dramatically.”
Read more from the Monterey Bay Aquarium.

Header Image: A raft of sea otters congregates off the back deck of the Monterey Bay Aquarium in kelp. Credit: Monterey Bay Aquarium / Tyson V. Rininger A raft of sea otters (Enhydra nereis) not seen in many years, congregates off the back deck of the Monterey Bay Aquarium.