CASPAR BEACH, Calif. (AP) — Joy Hollenback, with a welding hammer strapped to her wrist, donned blue fins and swam into the churning, chilly surf of the Pacific Ocean one fall morning to do her part to save the vanishing kelp forests in Northern California.
Hollenback floated on the waving surface to regulate her breathing before diving free into the murky depths toward the seabed. There she saw her target: voracious, kelp-devouring purple urchins.
Within seconds she smashed twenty of them to smithereens. “When you’re angry, it’s a cathartic way to get it all out,” Hollenback joked. “It’s ecologically sanctioned chaos.”
The veterinarian from Berkeley, California, is part of a group of volunteers who swim, snorkel and dive, armed with picks and hammers, with one mission: to crush purple urchins that destroyed 96% of California’s iconic bull kelp forests between 2014 and 2014. have largely destroyed. 2020, harming the red abalone and other marine life they supported.
The pilot project off the coast of Mendocino County is one of several initiatives California is testing to save such green marine ecosystems, which are declining worldwide due to climate change.
Kelp forests play an integral role in the health of the world’s oceans, one of the issues being discussed at the United Nations Climate Summit in Dubai.
Based on early observations, efforts such as culling sea urchins appear to be helping.
Biologists say they are starting to see small successes with experiments started several years ago, which offer hope of reversing the destruction, akin to clearing a rainforest.
Healthy patches of kelp and schools of fish returned this summer to small pockets of sea urchin crushing at Caspar Cove, 120 miles north of San Francisco.
Near Albion Bay, where commercial divers removed many of the sea urchins in 2021, biologists placed small kelp grown in a lab on 100-foot lines. In August, they discovered that the kelp had not only reached the surface, but was also reproducing.
“This is the first time we know of this happening in an open coastal environment,” said Norah Eddy of The Nature Conservancy, one of several organizations participating in the experiment. “What we want is for the kelp to start producing babies. This shows that these methods can be applied in these types of harsh environments.”
There are still enormous challenges that must be overcome before California bull kelp is on the road to recovery. But scientists say progress has eased fears that the forests were lost forever.
“This really makes the system hold on to the kelp that we have until we get to a better place,” said Kristen Elsmore, a senior scientist with the California Department of Fish and Wildlife.
Scientists will collect data over the next three years to determine which methods are most effective as California creates its first plan to restore and manage kelp.
Kelp was so abundant that the state managed it solely as a fishery, overseeing commercial and recreational harvests. Under the plan, kelp will now be managed as an ecosystem, reflecting the increased understanding of kelp’s importance.
“Kelp forms entire forests that support so many other species and so it has a cascading effect on the coastal ecosystem when you lose your kelp,” Elsmore said. “You lose an entire forest, not just one species.”
The plan could support recovery efforts from Australia to Chile, where kelp faces similar threats.
“The ultimate goal is for these systems to be truly self-sustaining and for the restoration part to actually give it a little push in the right direction,” he said.
Kelp is disappearing because a warming planet is raising ocean temperatures.
Along the West Coast, the problem began after 2013, when a warm body of water nicknamed “the blob” developed off the coast of Alaska and extended southward, wreaking havoc on marine ecosystems as far away as Mexico’s Baja Peninsula for four years California.
At the same time, a mysterious, devastating disease decimated the sunflower starfish, causing their arms to fall off and turning them into gooey masses, killing 90% of the population.
The starfish is the purple urchin’s main predator. After the disease killed more than 5 billion starfish, the urchin population exploded, devouring kelp and leaving seascapes with almost nothing but the spiny, bulbous echinoderms.
The loss of kelp prompted the California Fish and Game Commission to close the recreational fishery for red abalone in 2018. Commercial harvests of red sea urchins have also been damaged. Red urchins are preferred over purple urchins because they contain more edible uni or roe, but commercial divers say the quantity has shrunk with less kelp.
Bull kelp, an annual seaweed, starts as a microscopic spur that can grow up to 0.6 meters per day until it reaches 30 meters in height before dying back in the colder months. It thrives in cool, nutrient-rich water.
The California coast is home to bull and giant kelp, the world’s largest marine algae. Sea urchins have harmed both species, although the giant kelp forests have fared better.
Some believe the only way to restore kelp is to reduce purple urchins, which can remain dormant for years before re-gathering and eating new kelp growth. Chefs have started serving purple hedgehogs to build a market.
“Sometimes it feels strange, like you’re killing an animal that’s a native species, but it’s for the greater good,” said Morgan Murphy-Cannella of the Reef Check Foundation, the kelp restoration coordinator involved in the planting of kelp in Albion Bay. The volunteers monitor kelp forests from Canada to Mexico.
Josh Russo, a former abalone fisherman and founder of the Watermen’s Alliance, a coalition of spearfishing clubs, helped spark the sea urchin crush.
The first group was mostly local divers armed with sledgehammers, Russo said with a laugh. After struggling to swing them underwater, they turned to small welding and furniture hammers and ice picks.
Volunteers removed 80% of the purple hedgehogs from a section at Caspar’s Cove, Russo said. It is one of two places where California allows fishermen with a recreational license to catch an unlimited amount of purple urchins.
But crushing the hedgehog is not without controversy. Some fear it could spread sea urchin eggs, worsening the problem.
Russo has seen no evidence of that. Instead, he said, sea urchin density has decreased in the 300-by-300-foot (91-by-91-meter) section where schools of young rockfish zoomed among the towering algae this summer.
“This went from being barren to just being full of life again,” Russo said.
Scientists say nothing can replace natural enemies like the sunflower starfish.
After learning how to breed it in captivity, biologists build a population to reintroduce it. Sunflower starfish are in four California aquariums, including the Birch Aquarium in San Diego, which prompted the release of three aquariums in October.
At least four sunflower starfish were also spotted off the Mendocino coast this year, which Elsmore said is “super exciting” since none have been seen there in years.
There is still much to learn. Kelp hasn’t returned to all places free of sea urchins, and scientists don’t know why.
But the crush helps buy time to find permanent solutions.
The events take place from April to September and draw people from all over Northern California.
On a Saturday in September, volunteers included a paralegal, a factory worker, college students and a landscape contractor whose two Australian shepherds, “Swimmer” and “Breaker,” watched patiently from the beach. One artist collected the hedgehogs to make purple dye for clothing.
Hollenback, the veterinarian, started participating in May 2022 after seeing the events on Facebook. She has hammered a whopping 82 hedgehogs in the 50 seconds she can hold her breath. On this day the sea at Caspar Cove was too turbulent, so the group moved to a neighboring bay to look for urchins.
“It can feel counterintuitive to kill animals when my job is to save them,” she said. “But this helps save the entire ecosystem.”
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