Purple urchin removal program seeks to prove efficacy of culling
FORT BRAGG >> Representatives from Reef Check, The Nature Conservancy and UC Davis provided an update on the Reef Check Kelp Restoration Project to 100 followers of the Noyo Center Science Talks via Zoom, Feb. 25.
One of the goals of the project was to determine if culling the purple urchins to the international standards of two-urchinsper-sq. meter would be sufficient to reverse the urchin barren, and
allow the kelp forest to regrow in the ideal conditions off the Mendocino Coast.
The purple urchins are being removed to see if it will bring back the kelp forest, which has been decimated by a combination of warm water and the overpopulation of purple urchins. When the kelp forest died out the abalone starved and the commercially viable red urchins were overrun. It shut down the sports abalone season and the red urchin commercial fishing industry saw an 80% percent decline,
creating a double hit to the local economy. It also impacts fin fisheries and insects that live in the kelp and the shorebirds that feed on the fish and insects.
The two urchins per sq. meter baseline was established by researchers in Japan, Norway and New Zealand — which have all faced purple urchin barrens in recent years.
Tristin McHugh, formerly of Reef Check and currently the Kelp Project Director for the Nature Conservancy explained that a healthy kelp forest could support more than two urchins, but to reverse the damage done by the purples, two per sq. meter has been established as the goal. This will give the kelp a fighting chance to regrow the forest.
The program — which was funded by the Ocean Protection Council for $500,000, the California Department of Fish and Wildlife for $75,000 and the Watermen’s Alliance for $60,000 — set up two similar locations in Noyo Bay where the number of urchins, both purple and red were
counted. One area would be culled and the other would be a control group. Local fishermen were hired for the work, and a total of six boats participated. The fishermen were also allowed to remove legal-size reds. The population of reds, which are used to collect uni (a Japanese delicacy), has been pushed out by the purples, as have the abalone and kelp species.
The program was supposed to start in early 2020, but was delayed due to the pandemic and didn’t get started until May. This reduced the amount of time that it was safe to cull in the waters around Noyo Harbor.
The effort around the restoration project actually started in early 2018 when the “KELPERS” alliance started holding community meetings coordinated by the Noyo Center
for Marine Science to explain the situation and the problem it was causing. The KELPERS alliance is a consortium of nonprofits, commercial fishermen, government agencies and sport divers all working together to restore the forest off the Mendocino Coast. The plans which Reef Check is implementing were developed by
California Department of Fish and Wildlife and the Greater Farallon’s Association in conjunction with the KELPERS consortium.
The first three months of the project were dedicated to surveys, cordoning off the areas and hiring personnel. The Downee’s boat, the Cyndi Lynn, out of Fort Bragg, was the first out on
Aug. 4. A group of shoreline volunteers waited at the docks for the haul to begin the laborious sampling effort that would provide data about the urchin’s stomach contents, reproduction viability, size and health.
The project continued culling through October and removed 26,535 pounds of urchins over a period of 27 days. The work was done in a 10-sq. meter area. The onshore volunteers sampled 6078 urchins.
The results were mixed: While they were able to significantly reduce the purple urchin population, when combined with the red urchin they could not get below two urchins per sq. meter. Since the reds are an income-producing fishery, they have take and size limits that are regulated by CDFW, and it wasn’t clear if removing undersized reds would be allowed going forward.
In an email from James Ray, Kelp Restoration Coordinator for CDFW, back in
October, efforts to authorize the removal of the reds was more difficult than anticipated, especially in historic red harvest areas like Caspar Cove. The kelp project was specifically supposed to focus on Caspar Cove after Noyo Bay.
To account for the controversy of removing reds in Caspar Cove, the project will move to Albion Bay in 2021. But there was some good news: Reef Check project reported juvenile kelp trying to reestablish itself in the test area, which according to McHugh, suggests the kelp spores in the area are still viable.
With McHugh’s move to the Nature Conservancy, the existing staff at Reef Check; Ian Norton the Northern California Survey Coordinator; and Morgan CannelliMurphy, the Kelp Restoration Coordinator, will all be taking over management of the kelp restoration project.
Funding for 2021 has not been finalized but, according to Murphy, an announcement is expected soon. At the Nature Conservancy, McHugh will be focused on supportive projects like the efficacy of trapping versus culling urchin, an experimental bull kelp farm in Humboldt Bay and drone imaging of kelp beds to monitor the kelp forest’s status.
While the project has lofty scientific and environmental goals, it also is helping the local commercial fishing fleet. In 2019, Grant Downee said he saw a 75 percent drop in income — but vowed to stay in Fort Bragg, whatever it takes. Downee and six other boats were paid to help cull the purple urchins.
For more information or to donate to Help the Kelp, visit the Noyo Center for Marine Science at noyocenter.org/help-thekelp/; for more about Reef Check, visit reefcheck. org, and to find out more about the Watermen’s Alliance, visit facebook.com/ groups/158992911481142/.