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