Kelp Restoration Project to Pluck Purple Urchins from Santa Barbara Channel

New Pilot Project Will Sell Problematic Purples to Restaurants or Turn Them into Agricultural Products

Photo of an over-population of purple urchins grazing on a kelp holdfast on the backside of San Miguel Island. | Credit: Jim Knowlton

Santa Barbara’s waters have seen everything when it comes to kelp restoration — from octopus condos to cement igloos. But another contender is entering the ring: urchin-hunting.

Well, something like that. This new pilot project will remove kelp-eating purple urchins from one acre of the Santa Barbara Channel, giving the region’s historic kelp forest a fighting chance at growing back.

By culling the problematic purples and selling them to restaurants or turning them into agricultural products, the project’s aim is to restore the kelp while avoiding waste.

Santa Barbara, like other parts of the state, is affected by “urchin barrens” — bare seafloor where urchins gobble up any new kelp before it can grow. Warmer waters due to climate change, and past El Niño storms, decimated the once-abundant kelp forests that surrounded the Channel Islands and lined the coast from El Capitan to Rincon Point. With the addition of a sea-star disease that nearly wiped out one of the urchin’s primary predators, the purples have been able to run amok.

An urchin barren on a reef behind San Miguel Island, which used to be a productive fishing area. | Credit: Jim Knowlton

However, by harvesting the urchins, the kelp is able to grow back fairly easily, said project leader Kim Selkoe, the executive director of the Commercial Fishermen of Santa Barbara (CFSB) and a research scientist at UCSB.

Although this is not a new concept — the Independent’s food guru Matt Kettmann first noticed the rising popularity of purple urchins, or “hotchis,” in 2019 — it is a first-of-its-kind project for the CFSB. It will build on the existing urchin-ranching operation at The Cultured Abalone, an onshore shellfish farm, where the best of them will be fattened up for sale. The tinier ones will be ground up into a calcium-rich fertilizer by Get Hooked Seafood.

“Our fishing association really felt like restoration was overdue for some of the urchin barrens that used to be highly productive fishing grounds,” Selkoe said. “There’s just more and more evidence that active restoration is flipping these systems back into a kelp-dominated state.”

Urchin diver Jeff Maassen picks purple urchins off an urchin barren. | Credit: Jim Knowlton

[Click to enlarge] Purple urchins, or “hotchis” (meaning “hedgehog”), have become a delicacy in recent years. The collected urchins will either be sold to restaurants or ground up into calcium-rich fertilizer. | Credit: CFSB

By marketing the urchins, they can afford future diving and restoration efforts and support Santa Barbara’s ocean economy, Selkoe said. Their team is currently evaluating focal sites at San Miguel Island and hope to begin work this spring.

Fisherman Trent Petersen, one of the divers who will be harvesting the purple urchins, said the project is a way for different sectors to come together and “bridge the gap” between science, restoration, and fisheries. “That to me is an overall win,” he said.

For the two-year initiative, the CFSB is also partnering with The Nature Conservancy California, UC Santa Barbara (UCSB), Santa Barbara City College (SBCC), and The Bay Foundation, and efforts will be funded by Eric and Wendy Schmidt.

Ultimately, the small pilot project will help them develop a long-term model for kelp restoration. Part of the project includes internships for SBCC and UCSB students to be involved in the process and foster a pathway for ocean-related careers.

“The final product of this pilot is really a master plan for a large-scale restoration project and funding to be able to clear 10 acres or even more over the long term,” Selkoe said.