Kelp forests and Sea Urchin Barrens

In 2015 a “blob” of warm water, combined with a strong El Niño created extra warm water in the Monterey Bay and slowed the growth of giant kelp. This warming caused sea urchins, who typically thrived in their niches, to proactively search for kelp instead of waiting for it to drift by. This all created what is known as sea urchin barrens.  


The sea otters in the Monterey Bay responded to the increase in sea urchin barrens by eating a lot. Like, three times as many as they did before the 2015. Sure, it was all good for the sea otters, but it did nothing to decrease the urchin sea barrens where the urchins were found to be unhealthy. “Some people call them zombie urchins,” Joseph Smith of UCSC said. “You open them up, and they’re empty. So the otters are ignoring the urchin barrens and going after the nutritionally profitable urchins in the kelp forest.”

An approach to clearing sea urchin barrens.