Purple urchin has overrun kelp forests, commercial divers and conservationists have have joined forces to restore the North Coast’s marine ecosystem - The Mendocino Voice

Posted: 10 Aug 2020 01:34 PM PDT

Publisher's note: Lana Cohen is a Report For America fellow covering the environment and natural resources for The Mendocino Voice and KZYX. Her position is supported by the Community Foundation of Mendocino, the GroundTruth Project's Report for America initiative, and readers like you. If you'd to support Lana's work you can contribute at this website or email us at publisher@mendovoice.com. Lana is available at LCohen@mendovoice.com. The Mendocino Voice maintains full editorial control of this work.

FORT BRAGG, 8/10/20 — Fort Bragg resident Patrick Downie has been diving for red urchin for 40 years. When he started, the industry was a lucrative one, offering a job he felt lucky to have, where he could make enough money to live comfortably and have a little extra to save. Now, he is barely hanging on, making as much as he is spending to keep up with maintenance on his boat and dive gear. He's considering heading south, where red urchins are more abundant, changing fisheries, or selling his boat. But he doesn't want to do any of these things. He loves North Coast urchin diving, which he considers more of a lifestyle than a job, and hopes to pass his boat down to his son, Grant Downie, who is also a red urchin diver.

The father-son duo are the last red urchin divers left in Fort Bragg. They're holding out hope that the industry, which used to support hundreds of divers, will bounce back. But while the red urchin fishery is still floundering, the Downie's have a new mission — helping conservation groups restore the North Coast's kelp forests, which have been decimated by climate change.

More than 90% of the North Coast's kelp, which provides shelter and food for thousands of species, has disappeared in the last decade, devastating marine life, fisheries, and the coastal economy. Now, marine conservation groups, state institutes, and recreational and commercial divers are coming together to save the decimated ecosystem. One of those conservation groups is Reef Check, an international nonprofit dedicated to restoring and preserving tropical coral reefs and temperate kelp forests. On the morning of Tuesday, August 4, with the help of the Downies, Reef Check kicked off their kelp restoration project.

The pair were hired by Reef Check to collect the red urchins' problematic cousin, purple urchins, in Noyo Bay. Along with warming waters caused by climate change, a massive influx of purple urchins, which have no predators left in this region, a have devastated the North Coast marine ecosystem by overgrazing bull kelp, a type of thick, brown algae that is foundational to the North Coast's temperature rocky reef environments.

"When we think about kelp loss, that's like losing the three-dimensional structure of coral reefs," said Tristin McHugh, biologist and Reef Check's North Coast regional manager. "Losing the structure which everything else needs to survive."

The Downies on their boat, heading out of Noyo Harbor before getting ready to dive for purple urchin

Kelp provides shelter, nutrients, and oxygen to all creatures that call temperate reef ecosystems home In addition to the many marine creatures that rely on kelp, seals, whales, sea otters, great blue herons, shore birds, and a variety of other creatures rely on the algae.

A century ago, the purple urchin populations were kept in check by two predators — sea otters and sea stars. But in the early 1900s the sea otter population (which is still on the federal endangered species list) was hunted almost to extinction. Then, starting in 2013, there was a mass die off of sea stars caused by a disease called sea star wasting syndrome. Purple urchins were left without predators. Purple urchins have an insatiable appetite for bull kelp which looks a bit like a balloon, with a floating gas-filled bulb on one end and a long tail that grows out of the sand and can often be seen floating on top of the water or washed up on shore.

In 2008, the kelp started slowly and incrementally disappearing. Then, in 2013, when the Northeast Pacific Ocean experienced a record-breaking marine heat wave, which increased ocean temperatures by 2.5 degrees Celsius (4.5 degrees Fahrenheit) for almost a full calendar year, the rate of die off drastically increased.

At the same time, the purple urchins, with nothing to stop their population from exploding, started chowing down on all the kelp and any other type of algae that was in their path.

What was left were urchin barrens, desolate areas void of almost everything except for spiny, eggplant purple, urchins which blanket the ocean floor eating everything in their path.

Divers like the Downies have experienced this change first hand. "It's really getting scary, it's nothing like I've ever seen before," said Patrick. "I think we're going on four to five, pushing six years now where there is no kelp. We can drop down to where we used to work, there's no food, no kelp, in probably 80% of our coastline now. They've all been taken over by these little [Strongylocentrotus] purparatus [or purple urchin]. They're like a million ants just looking for food. As fast as the kelp is growing, these purpuratus, they just take over and they'll eat anything."

Grant and Patrick Downie on their boat after a day of diving for purple urchin

The underwater world, which used to be akin to a rainforest, filled with light, life and color, is now a bleak, gray landscape, with only rocks, sand, and, of course, purple urchin. During the Downie's four hours under water last week, they barely saw any kelp, and only spotted one starfish and one abalone.

"There's not a lot of kelp present, and there was no growing bull kelp attached," said Grant. However "there's purple urchins all over." Grant explained that the purple urchins have formed into patches, or groups of 10 to 50 urchins. "As we work our way through the area, every five to 10 feet you'll come upon a patch of 10 to 50 purples eating everything they can find," said Grant.

With the bull kelp went the North Coast's abalone fishery, once worth $44 million per year before it's collapse in 2018 and red urchin fishery, worth $3 million in its prime. Other fisheries shorebirds that rely on a healthy marine ecosystem were also adversely impacted.

"The whole kelp forest disappearing has affected so many different fisheries even though you don't really see it," said Patrick. "We've lost a lot of our shops that would cater to different fishing businesses. We lost our dive shop, so now it's even hard to get dive equipment. The dive shop was here for years and I could go to the dive shop to get my bail out bottle [a backup air tank] filled. Now I have to drive three hours to get it filled, but at least I do have a backup air supply when I'm diving deep," he said.

Scientists believe that removing the purple urchins might give the bull kelp the space to reestablish, which could play a part in ultimately bringing back North Coast's many fisheries.

The North Coast's kelp forests, which grow in areas between two meters (around six feet) and 30 meters (almost 100 feet) deep, used to be filled with life. The algae grew in dense thickets, providing homes for abalone, red urchin, fish, and all sorts of invertebrates.

Scientists say the ultimate cause of the disappearing kelp is warming waters caused by global climate change, but locally, the drastic increase in purple urchin population make it extremely difficult, if not impossible, for the kelp to grow back without human intervention.

That's why Reef Check is working with divers to remove purple urchin and assess the underwater ecosystem — counting algae, invertebrates, fish, and other species in the bull kelp ecosystem. They hope that without so many purple urchins, the bull kelp will have the space to flourish and the once productive North Coast reefs can bounce back.

Reef Check is paying the divers $500 per day to pull purple urchins out of Noyo Harbor and Caspar Cove and deliver them back to Reef Check's local team to be counted and analyzed for among other things, reproductive potential and size.

Support The Mendocino Voice

We depend on your support. A generous gift in any amount helps us continue to bring you this service.

Become a Member!

Most of the money to fund Reef Check's kelp restoration project comes from Ocean Protection Council, a State of California agency dedicated to protecting California's ocean and coastal ecosystems. The project also received $75,000 from the California Department of Fish and Wildlife.

This Tuesday, August 4, was the first day of Reef Check's kelp forest restoration project, a baseline study that the organization hopes will help scientists figure out what the most effective method of removing urchin is, if urchin removal will help the kelp reestablish, and in general, what is going on under water in the temperate kelp ecosystem.

McHugh, who is a biologist, believes bringing back kelp is crucial to restoring the marine ecosystem and the North Coast's fisheries.

"Every other sector of the coast is tied into the kelp forest ecosystem. So when we think about how important the system is I almost ask you to ask yourself how important are the redwoods to you, and that is the same sort of regard that we should think about kelp forest ecosystems in," said McHugh.

It was in 1980 when Patrick Downie first slipped on his scuba diving gear and dropped down into the cold depths of California's Pacific Ocean in search of red urchin.

"Back in 1980 a friend of mine saw an ad in the newspaper that said 'divers needed' and I just happened to have the ability to dive as a young kid and so it was really easy for me. And I went down there and around 20 people showed up and the guy took as many people as he could get on the boat safely and whoever brought in the most [red urchin] got to work," recounted Downie, who landed the job.

But early this week, after 40 years of red urchin diving, Patrick, along with his son, dropped down to retrieve as many purple urchins as possible from the depths of Noyo Harbor.

The Reef Check team set aside 10 total acres for restoration just outside of Noyo Harbor in Noyo Bay, which they hope to completely rid of purple urchin.

Grant Downie watching as his father, Patrick, uses a crane to move purple urchins from his boat to a crate in Noyo Harbor. Credit: Claire Nasr, California Sea Grant Fellow

The Downies, who have been involved in volunteer purple urchin removal for years, are happy to have the opportunity to share their knowledge with Reef Check to try and restore the ecosystem to what it once was — a thick forest of brown bull kelp, packed with abalone, red urchin, invertebrates, fish life, and more.

But the cash definitely doesn't hurt either. Times have been tough.

For most of Patrick's years as a red urchin diver, he was diving around 40 feet deep and pulling in as much as 2600 pounds of red urchin a day, worth about $1000 at the time. Now, even though he's in his mid-60s, he's taking more risks in the ocean — going out farther and dropping down deeper, sometimes up to 90 feet below. The deep dives hurt Patrick's arthritis and make him feel like he "just cut a cord wood." But he keeps at it, even though on a good day he only has around 300 pounds of red urchin to show for his dangerous work, worth less than $500.

The coronavirus pandemic didn't make things easier. "Now we have the virus thing, so that's really affected the markets. Restaurants closing right and left, sushi bars closing right and left, and that was our main market," said Patrick.

COVID also affected Reef Check's kelp restoration project, which was supposed to kick off in the spring with divers from around the state.

After months of delay, the launch of the kelp restoration project went smoothly. At 8:30 a.m. in the morning on Tuesday, August 4, McHugh and her team met up with the Downie's to give them some gear and make sure they were ready to go.

The winds, at 15 to 25 knots, were stronger than the ideal, but the swells, only NW 5 feet at 9 seconds, weren't a concern. "It's diveable for sure," said McHugh, standing under a clear sky and looking out at the ocean from the windy bluffs above Noyo Harbor. Still, she explained that morning is usually when the weather is best and the ocean calmest, so worsening weather throughout the day was expected. If the ocean became too rough for diving, the project's launch day would have to be cut short.

Reef Check is far from the only organization involved in kelp restoration. On California's North Coast, almost 20 nonprofits (including Reef Check), businesses, government agencies, and commercial and recreational divers have come together over the past six years to try to help the bull kelp reestablish along the Mendocino and Sonoma coasts. "Think of it like a study group," said McHugh, of the amalgamation of groups that call themselves KELPRR. "Each institution has their own piece that they're working on but KELPRR is that place they come together to learn from each other and expand their breadth of knowledge."

Reef Check scientists and volunteers recording a random sample of purple urchins

Sheila Semans, the executive director of the Noyo Center for Marine Science, a nonprofit focused on marine education and conservation and a partner of KELPRR, said creating KELPRR was important because there is still very little known about the rapidly disappearing temperate kelp ecosystem. "We wanted to put together a collaborative program to address this incredible issue and get everyone working together to enhance each other's work. It's what we could do, there's an amazing amount we don't know about bull kelp," said Semans.

Although there is still much to learn, knowledge of California's North Coast temperate kelp ecosystem has been growing. Laura Rogers-Bennett, Ph.D and Cynthia A. Catton, Ph.D, in their 2019 study, Marine heat wave and multiple stressors tip bull kelp forest to sea urchin barrens, published in the peer reviewed journal, Nature that bull kelp forests have been reduced by more than 90% along more than 350 km (217 miles) of coastline from Marin to the Mendocino-Humboldt border.

The decline of cornerstone kelp species, which can grow up to almost two feet per day and provide valuable ecosystem services, is not unique to the North Coast. Rogers-Bennet, a senior environmental scientist with the California Department of Fish and Wildlife Marine Region and Catton, a scientist at the California Department of Fish and Wildlife's Bodega Marine Laboratory explained that kelp, which historically have occupied 25% of the world's coastlines, providing habitat, food and carbon sequestration, started disappearing in 2013 when the Northeast Pacific Ocean experienced a record-breaking marine heat wave. The marine heat wave, which increased surface temperatures by 2.5 degrees Celsius (4.5 Fahrenheit), started in Alaska's Bering Sea and spread all the way down the California coast to Baja California, lasting for almost an entire calendar year. This was the longest marine heat wave ever recorded in the Pacific.

Although this is a global problem, Rogers-Bennett and Catton note that the bull kelp forests along the California coast, and especially in the northern third of the state, saw the impact of kelp loss first and most acutely.

Grant Downie dropping purple urchin into a crate to record and analyze a random sample

Rogers-Bennett and Catton wrote in their study that "the region north of San Francisco to the Oregon border historically supported extensive, nearly pristine, productive, and persistent bull kelp, Nereocystis luetkeana, forests. Human population densities and development are low in the region, so no abrupt anthropogenic impacts to ocean conditions and ecosystem health were anticipated. A series of perturbations including a loss of sea star predators of urchins, prolonged warm-water conditions, and a population explosion of purple sea urchins occurred prior to and concurrently with an abrupt shift from bull kelp forest to persistent urchin barrens."

Purple urchin will eat anything, even rocks and sand when nothing else is around. When going through a random sample of the 487 pounds of purple urchin the Downie's cleared off the bouldery ocean floor last Tuesday, Reef Check's restoration technicians, Morgan Murphy-Cannella and Ian Norton, found that in addition to algae, the purple urchins had consumed rocks and sand.

Reef Check restoration technician Ian Norton looking at the contents from a purple urchins stomach

Murphy-Cannella and Norton, who were hired by Reef Check specifically for this project, were charged with cracking open the purple urchins to find out what they were feeding on as well as whether or not they havereproductive capabilities. They hope to analyze and record 150 urchins per day. "We're just looking for an idea of what they're munching on out there," said Norton as he used a scalpel-like tool to scrape out the gonad, the purple urchins reproductive organ, from its shell. "We just want an idea of what they're eating out there —red algae, green algae, rocks, sand, and what they're willing to eat."

This work is providing Reef Check with baseline information on what the state of the algae and the purple urchins are right now, so that as they continue kelp restoration they can monitor changes.

The presence of rocks and sand in the purple urchins tells a dark story about the current state of Noyo Bay — that there is not much else out there to eat. The urchins, which generally grow to about four inches in diameter, prefer a diet of more algae, less rock and sand. But they'll take what they can get, and they'll take all of it.

That's consistent with what the Downie's saw during their four hours under water on Tuesday. "We've got some red algae and red lettuce growing, other than that there's not a lot of kelp present. There was no growing bull kelp attached and no palm kelp that I saw," said Grant.

Although the picture is stark, the Downie's haven't given up on the possibility that the red urchin fishery might bounce back. But still, they realize the fate of what they love, red urchin diving, is unsure. "I am worried about the future of the industry," said Grant. "I'm buying a house on the coast which is expensive, I have two kids now and I really wanted to have them grow up in Fort Bragg. It's a small quaint little town but I loved it growing up."

Grant hopes that the work that Reef Check, KELPRR, and himself are doing might help get him back in the water diving for red urchins. "Since the marine protected areas were enacted [in 2012], shortly after is when I noticed reef check," said Grant. "I think it's great. We see a lot of bottom time and a lot of spots that they don't see. I think sharing our knowledge can help everything. Since I've been in contact with Tristin and Reef Check over the last year I've really been forwarding knowledge from what I see out deep just because a lot of the scientific divers aren't going deeper than 60 feet [Grant and his father often go to 80 or 90 feet, the only place left they can find red urchin] so everything we've seen in the last three years diving deep is really part of the unknown."

The Downie's won't be the only divers involved in Reef Check's restoration efforts. Other commercial divers will head into Noyo Bay and the deeper waters of Caspar Cove to collect urchins, and volunteer recreational divers will crush the urchin in shallower areas in Caspar. By separating the cove into areas where the urchin will be crushed and left there versus plucked and removed, Reef Check can monitor the effectiveness of two different methods of urchin removal. "It's like a cost benefit of each of those methods," said McHugh. "Is one method more effective than the other? We simply don't know yet."

As Reef Check and other organizations are working hard to give the kelp a boost, the North Coast kelp population is showing some natural recovery as well. "This year we've started to see kelp showing up in places that we haven't seen it in for years," said McHugh. For example, in Portuguese Beach, another area Reef Check is monitoring in, they've found that many of the purple urchin that were occupying the area last year are gone.

Scientists don't yet know all the factors that are helping the kelp, but McHugh says cold ocean temperatures are likely playing a role. From 2013 to about January 2019, the Blob, a large mass of warm water in the Pacific, was sitting right off the North Coast. But as the year turned, the blob dissipated in this area. "My divers and I have been finding 46-degree water, which is a nice temperature that kelp likes to grow in," said McHugh.

Everyone involved in kelp restoration has their own reason for caring about the hardy, brown algae. McHugh believes kelp is foundational to our very existence on this planet. "Kelp is part of the reason why we breathe. Carbon buffering, nutrient transport, water transport, larval dispersal of fish all over the place. There are such deep ties to why this resource is so foundational to our very existence. At the time that missions came and colonized this area, that regard for the ocean became completely lost and so We've been living in this moment where we have shown relative disregard for what the kelp ecosystem actually is and what it means to us. We need to tune into why we're here to begin with. Do you love seeing whales migrate? Do you love seeing your favorite birds on the beach? Do you love seeing the harbor seals play? That is all here because of the kelp."

Search This Blog

Acuarium