Incredibly interesting article on the relationship between otters, sea urchins, and the kelp forest. Did you know that sea otters are choosing to eat the more nutritious sea urchins that live off the kelp forests instead of the urchins found in the sea urchin barrens? Scientists are working hard to find ways to save our kelp forests and otters can help!
Sea otters have long been recognized as a classic example of a keystone species, a dominant predator that maintains 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.
In 2017, UC Santa Cruz graduate student Joshua Smith set out to understand why. “Here in Monterey Bay, we now have a patchy mosaic, with urchin barrens devoid of kelp directly adjacent to patches of kelp forest that seem pretty healthy,” Smith said. “We wanted to know how did this sea urchin outbreak happen where there are so many otters, how did the otters respond, and what does that means for the fate of kelp forests here on the Central Coast?”
Working with a team of sea otter researchers at UCSC, the U.S. Geological Survey, and the Monterey Bay Aquarium, Smith conducted intensive underwater surveys along the Monterey Peninsula over a span of three years. The study built on decades of long-term monitoring of sea otter populations and kelp forest ecosystems along the California coast.
Smith’s findings, published March 8 in Proceedings of the National Academy of Sciences, tell a fascinating story of how the behavioral responses of predators and prey to changing conditions can determine the fate of an entire ecosystem.
To check out the rest of this article “Sea otters maintain remnants of healthy kelp forest amid sea urchin barrens”