Sea Otters Love Clams

Sea otter eating clam

What do sea otters like to eat in the Elkhorn Slough?  Clams, and lots of ’em!  

If you’ve ever kayaked the slough at low tide, you’ve probably seen discarded clam shells all along the shoreline.  Well there’s a good reason for that.  Researchers have found that in the Elkhorn Slough, over 80% of a sea otter’s diet consists of clams.  The approximate edible biomass of two of their favorite clam species, Washington (Saxidomus) and gaper (Tresus) clams, is 52g and 98g respectively.  That means a 75 lb otter eats between 100 and 150 clams per day to meet its nutritional and energetic demands. Remember, an otter must consume approximately 25% of its bodyweight in prey each day just to stay alive!

Cool Otter Fact:
On, we watched an otter eat over 20 clams in an hour!


Otter mom sharing clam with pup

We’d like to thank our research colleagues from U.S.Geological Survey, Monterey Bay Aquarium, University of California Santa Cruz, California Department of Fish & Wildlife and Elkhorn Slough National Estuarine Research Reserve for sharing some of their initial findings from the Coastal Conservance Elkhorn Slough Study.

For more info on this multi-year study, check out:


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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.