CASPAR BEACH, Calif. (AP) – With a welding hammer strapped to her ankle, Joy Hollenback donned her blue fins and swam out into the turbulent, cold Pacific waves on a fall morning to do her part to save Northern California’s vanishing kelp forests.
Hollenback floated on the rocking surface to catch his breath before diving freely into the dark depths towards the seafloor. There he spotted his target: greedy, algae-eating purple urchins.
He shattered 20 of them in seconds. “If you’re angry, this is a cathartic way to vent,” Hollenback joked. “This is ecologically sanctioned mayhem.”
The Berkeley, Calif.-based veterinarian is part of a team of swimming, snorkeling and diving volunteers armed with picks and hammers on one mission: decimating 96% of California’s iconic bull kelp forests between 2014 and 2014. crushing purple chestnuts. 2020, and with it harm, the red abalone and the other marine creatures they support.
The pilot project off the coast of Mendocino County is one of many initiatives California is testing to recover leafy marine ecosystems that are declining worldwide due to climate change.
Algae forests play an integral role in the health of the world’s oceans, one of the topics discussed at the United Nations climate summit in Dubai.
Based on initial observations, efforts such as culling urchins appear to be helping.
Biologists say they are starting to see small successes with experiments that began a few years ago, offering hope of reversing the devastation, likened to the complete felling of a rainforest.
Healthy patches of kelp and schools of fish returned this summer to small urchin-crusted sections in Caspar Bay, 160 miles (200 kilometers) north of San Francisco.
Near Albion Bay, where commercial divers recovered most of the urchins in 2021, biologists placed tiny lab-grown kelp in 30-foot lines. In August, they discovered that the algae was not only rising to the surface but also reproducing.
“This is the first time we know this is happening in an open coastal environment,” said Norah Eddy of the Nature Conservancy, one of several organizations involved in the experiment. “What we want is for the moss to start giving birth to babies. This shows that these methods can be done in such harsh environments.”
There are still major challenges to overcome before bull kelp in California can get on the road to recovery. But scientists say this progress allays fears that forests will disappear forever.
“This sets up the system to hold on to the algae we have until we get to a better place,” said Kristen Elsmore, a senior scientist with the California Department of Fish and Wildlife. said.
As California creates its initial plan to restore and manage the algae, scientists will collect data over the next three years to determine which methods are most effective.
The kelp was so abundant that the state managed it solely as a fishing area, managing commercial and recreational harvests. Under the plan, moss will now be managed as an ecosystem, reflecting the growing understanding of moss’s importance.
“The green makes up entire forests that support many other species, and so when you lose your kelp it creates a cascading effect on the nearshore ecosystem,” Elsmore said. “You’re not losing just one species, you’re losing an entire forest.”
The plan could inform restoration efforts from Australia to Chile, where the moss faces similar threats.
“The ultimate goal is for these systems to be truly self-sustaining and for the restoration part to gently nudge it in the right direction,” the scientist said.
As a warming planet increases ocean temperatures, algae is disappearing.
The problem along the West Coast began after 2013, when a mass of warm water nicknamed “the blob” developed off the coast of Alaska and extended south, wreaking havoc on marine ecosystems as far as Mexico’s Baja California peninsula for four years.
At the same time, a mysterious devastating disease decimated sunflower sea stars, causing their arms to fall off and turning them into sticky masses, killing 90% of the population.
Starfish are the main predator of purple urchin. After the disease killed more than 5 billion sea stars, the urchin population exploded, swallowing algae and leaving seascapes with almost nothing but spiny, globular echinoderms.
Loss of kelp led the California Fish and Game Commission to close the recreational red abalone fishery in 2018. Commercial harvests of red chestnuts also suffered. Red urchins are preferred over purple urchins because they contain more edible uni, or roe, but commercial divers say that quantity decreases as the amount of algae decreases.
Bull kelp, an annual seaweed, begins as a microscopic spore that grows up to two feet (0.6 meters) per day until it reaches up to 98 feet (30 meters) before dying during the colder months. It thrives in cool, nutrient-rich waters.
Bull and giant kelp, the largest seaweed in the world, are found off the coast of California. Urchins damaged both species, but giant kelp forests fared better.
Some believe the only way to revive the moss is to reduce the purple urchins, which can remain dormant for years and then reemerge and eat new moss growth. Chefs started serving purple chestnuts to establish a market.
“Sometimes it feels weird, like you’re killing this animal that’s a native species, but it’s for the greater good,” said Morgan Murphy-Cannella of the Reef Check Foundation, a kelp restoration coordinator involved in the kelp planting in Albion Bay. Its volunteers monitor kelp forests from Canada to Mexico.
Josh Russo, a former abalone hunter and founder of the Watermen’s Alliance, a coalition of spearfishing clubs, helped initiate the urchin crush.
The first group consisted mostly of local divers carrying sledgehammers, Russo said with a laugh. After trying to swing them underwater, they turned to small welding and furniture hammers and ice picks.
Volunteers removed 80% of the purple urchins in one section of Caspar Bay, Russo said. It is one of two spots where California allows licensed recreational anglers to take unlimited amounts of purple urchins.
However, crushing chestnuts is not without controversy. Some fear this could make the problem worse by spreading urchin eggs.
Russo saw no evidence of this. Instead, he said, urchin density decreased in the 100-by-100-yard (91-by-91-meter) section, where schools of juvenile rockfish bobbed among rising algae this summer.
“This went from being barren to being full of life again,” Russo said.
Scientists say nothing can replace natural predators like the sunflower starfish.
Once biologists learn to breed it in captivity, they create a stockpile to reproduce it. Sunflower sea stars are found in four California aquariums, including the Birch aquarium in San Diego, which has three of them spawning in October.
At least four sunflower starfish have also been spotted off the Mendocino coast this year; Elsmore said it was “super exciting” since he hadn’t been seen there in years.
There’s still a lot to learn. The moss has not returned to all urchin-free spots, and scientists don’t know why.
But cracking helps buy time to find permanent solutions.
Events run from April to September and draw people from all over Northern California.
On a Saturday in September, the volunteers included a paralegal, a factory worker, college students and a landscaping contractor as two Australian shepherds, “Swimmer” and “Breaker,” watched patiently from the beach. An artist collected chestnuts to make purple dye for clothes.
Veterinarian Hollenback began participating in May 2022 after seeing the events on Facebook. He beat up about 82 urchins in the 50 seconds he could hold his breath. The sea was very turbulent that day in Caspar Bay, so the group headed to the neighboring bay to look for urchins.
“It may seem counterintuitive to kill animals when my job is to save them,” he said. “But this helps save the entire ecosystem.”
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