Urchins

Dive below the surface with our Aquatic Resources Group (ARG) to get a close-up view of an urchin barren and see how they're impacting kelp forests along the California coast.

Video by Sam Briggs, ARG Lead diver and field operations manager

Read more about the Aquatic Resources Group

“This is actually better than sustainable, because the more you fish it, the better off the kelp forest will be. This is a restorative seafood product.”

-Laura Rogers-Bennett, a research associate at the University of California, Davis and a scientist at the California Department of Fish and Wildlife

Written by Jane Park

Kelp forests are underwater forests that support some of the world’s most productive fisheries and unique ecosystems.  Kelp forests occur throughout the world.  California’s kelp forests are particularly unique, as our “redwood forests of the sea” are among the tallest and most productive of the world: Northern California’s “bull kelp” grow an average of 4 in./day and can reach heights over 100 ft. 

Kelp forests are integral to marine ecosystems along our coast because they provide habitat and food for numerous species. The Pacific Purple Sea Urchin, Strongylocentrotus purpuratus, will mow down the kelp forests if their populations are not controlled. In northern California, the sunflower sea star, Pycnopodia helianthoides, is a major predator of urchins. The sunflower sea star plays an essential role in maintaining the harmonious balance between the kelp forests and the urchins who walk among them.

Dense canopies of kelp are a well-known and much-loved feature of California’s coastal waters. Kelp forests create subtidal havens for marine life like red and white abalone, urchins, sea stars, and rockfish.

Scientists are mobilizing to aid California’s crashing kelp forests, which have been decimated due to a combination of stressors, including warming oceans, the disappearance of sea stars and an associated population explosion of purple urchins.

Considered a delicacy around the globe, sea urchins please the palates of the wealthy, showing up on sushi bars and swirled into pasta at fine restaurants. However, these spiny creatures in recent years have plowed through forests of bull kelp along coasts around the world.

The “sequoias of the sea” suck up carbon and shelter special species. They’ve been hit hard, but scientists, surfers, and more are banding together to save them.

Read more in National Geographic

Off the Northern California coast, there is a crisis beneath the waves. The kelp forest – seaweed that provided habitat and food for much of life in the ocean – is gone, wiped out by an exploding population of purple sea urchins.

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Urchinomics and its partner, the UC Davis' Bodega Marine Laboratory, are running a trial designed to develop methods for ranching purple sea urchins for profit, while at the same time addressing the consequences of a nasty ecological chain reaction.

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