Rising global temperatures have upset the balance of the ecosystem in our oceans, and each change has ripple effects that spell bad news for more and more species. These changes can be disastrous for kelps, the large brown (and sometimes green) algae that provide shelter and food for thousands of marine creatures, per the National Oceanic and Atmospheric Administration.
Now, an effort is underway to save the kelp from their greatest predator: the purple sea urchin. The Associated Press reported that volunteers in California are combating sea urchins via a direct method: by diving into the water and smashing the urchins with hammers.
Sea urchin populations have reportedly grown out of control because of the loss of their greatest predator, the sunflower sea star. A mysterious disease killed off 90% of the sunflower sea star population between 2013 and 2017, per NOAA, with the issue likely exacerbated by rising temperatures driven by human activities. Scientists are now breeding the sea stars in captivity and attempting to reintroduce them back into the wild.
In the meantime, however, the human divers armed with hammers have stepped up as a surrogate urchin predator. "If you're angry, it's a cathartic way to get it all out," Joy Hollenback, one of the volunteers, told the AP. "It's ecologically sanctioned mayhem."
Scientists say that the efforts are making a difference.
"This is really setting the system up to hold on to the kelp that we do have until we're in a better place," Kristen Elsmore, a senior scientist at the California Department of Fish and Wildlife, told the AP, adding, "The ultimate goal is for these systems to really be self-sustaining and the restoration part to really just be giving it a gentle nudge in the right direction."
Some critics of the practice worry that crushing the urchins could spread their eggs, worsening the problem. However, the experts behind the effort say they have seen no instances of that happening.
"This went from being urchin barren to just full of life again," Watermen's Alliance founder John Russo told the AP.
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