Sea otters maintain remnants of healthy kelp forest amid sea urchin barrens

Sea otters maintain the balance of kelp forest ecosystems by controlling populations of sea urchins, which are voracious kelp grazers. Since 2014, however, California's kelp forests have declined dramatically, and vast areas of the coast where kelp once thrived are now 'urchin barrens,' the seafloor carpeted with purple sea urchins and little else. This has occurred even in Monterey Bay, which hosts a large population of sea otters. A new study explains what happened.

source https://www.sciencedaily.com/releases/2021/03/210308152458.htm