Scientists say decades are needed to rebuild California’s abalone collapsed fishery

How To Get Involved

Fish and Wildlife Commission's Marine Resources Committee meeting:

9 a.m., Tuesday

Joseph A. Rattigan Building

Conference Room 410, 4th Floor

50 D Street, Santa Rosa

To participate via webinar go to

To participate via teleconference, call 877-402-9753 or 636-651-3141; access code 832 4310.

Go to to download a summary of the Recreational Abalone Fishery Management Plan

It could take until at least 2032 before California reopens even the slightest season for abalone diving and hunting along the North Coast, where depleted stocks have shut the popular sport fishery since 2018.

But that’s a best-case scenario envisioned by scientists studying the beleaguered red abalone population.

It will likely be three to six decades before abalone hunters will enjoy an open fishery like they are accustomed to, given current environmental circumstances and reproductive projections, the scientific team has concluded.

That rough timeline, though subject to ongoing debate and changes based on ocean conditions and population shifts in the coming years, suggests a whole generation of people could miss out on a sport that has inspired adventure and deeply held tradition for legions of families and friends across Northern California.

It also could mean die-hard divers in upper age groups may have to make peace with having bagged their last abalone.

“Some of us won’t live long enough to get back in the water, so that’s not making a lot of people happy,” said longtime ab diver Sonke Mastrup, invertebrate program manager and chief representative in the process for the California Department of Fish and Wildlife.

Jack Likins, a 74-year-old Gualala ab hunter known for bagging trophy-sized shellfish, summed up the gloom that has taken hold in the sport’s community. “I think fishermen like me are pretty discouraged,” he said.

The projections are part of a framework prepared for the state Fish and Game Commission to help guide management of the abalone fishery beginning next year, when an emergency three-year ban on the harvest of the mollusks expires.

Meeting on Tuesday

The commission’s Marine Resource Committee, meeting in Santa Rosa and San Diego, will discuss the document at a 9 a.m. session Tuesday and is likely to pass comments or recommendations on to the commission for consideration in April and beyond, Mastrup said. Special arrangements have been made for the public to participate via webinar or teleconference because of the coronavirus pandemic.

The draft report was developed by representatives from state Fish and Wildlife, the Ocean Protection Council, the Fish and Game Commission, The Nature Conservancy, stakeholders from the ab diving community, the Sherwood Valley Pomo tribe and members of the public. It addresses myriad subjects, including tools that might be used in the future to control how many abalone are harvested in any given year - size and catch limits, season limits and number of permits issued, for example.

But the primary focus was to define trigger points for shifting from a closed fishery to what’s called a “de minimis” fishery - one that allows a small amount of fishing by a limited number of participants but not enough to affect recovery of the stocks - and from closed to open fishery status, allowing as many people to participate as care to do so.

Modeling rebuild time

A group of scientists who worked specifically on computer modeling determined that the median rebuilding time from a closed fishery in 2021 to allowing the narrower fishery ranged from 11 to 31 years across different models. An additional 8 to 10 years would be needed if poor environmental conditions prolonged the abalone recovery period, the scientists found.

Under the limited fishery, participants would likely be chosen by lottery and allowed a very low catch limit. Those not selected one year would have advantage in the next year’s lottery.

The median recovery time before an open fishery could be scheduled was projected to be between 28 and 59 years.

Further refinement would depend on whether coastal waters were divided into two management zones - Marin/Sonoma coasts and Mendocino County coast to the north - or three - Marin/Sonoma coasts, Mendocino coast and Humboldt/Del Norte County coasts. The division is still up for debate.

“The reality is you can’t get past the biology of abalone,” Mastrup said. “It just takes them too long to grow up. That just creates this enormous lag.

“It’s not like deer hunting, for example. Deer in a year or two are old enough to be hunted. Abalone takes 12 years. It just slows everything down, and no matter what math you use, you can’t get past that.”

There might be opportunities for small numbers of fishermen to help harvest abalone needed periodically to test for size and reproductive fitness from various coastal sites. Such “biological fisheries” would allow abalone hunters to get a small taste of the sport while supplying needed data to fishery managers. Those assisting with the collection also would be able to take home the meat and shells.

Collapse of kelp forest

Marine wildlife managers already had been working for years on development of a long-term strategy for maintaining a sustainable abalone fishery when a cascade of ecological changes led to the collapse of the bull kelp forest off the northern coast of California and, thus, to the red abalone stocks that depend on it for survival.

Those changes included the onset of sea star wasting disease in 2013, which killed off many species of sea stars, whose ranks include an efficient hunter that helped keep smaller prey, including purple sea urchins, in check; a resulting population explosion among the tiny, voracious urchins, which compete with abalone for food and even prey on them; and the “warm blob” of 2014 and ’15, during which the nutrient-rich cold upwelling of the region was squelched, leading to poor health and reproduction of the bull kelp forest.

“We lost somewhere between 60% and 80% of the abalone we had five years ago,” Mastrup said. “I mean, it’s a huge drop. It fits the classic definition of a collapse.”

Surveys since show few signs of an overall recovery.

But there are some pockets where the kelp and abalone are doing a bit better than elsewhere, and some stakeholders are pushing state officials to manage the fishery on a finer scale that would permit an earlier harvest opportunity, even if it’s only in small amounts.

Few people are likely to want to go to the trouble to buy a permit and dive if the allowable take is only two or three a year, Likins said, contending that such limits would have limited impact on stocks.

“I think there can be a fishery if it can be managed pragmatically,” he said.

Josh Russo, president of the Watermen’s Alliance, a coalition of spearfishing clubs, said he also believes there could be a way for a divers to access the fishery on a limited basis sooner than projected.

But with no real sign of significant rebound in the abalone, “I don’t think they’re going to allow any take until it’s on the bounce-back. They’ve said that,” Russo said. “While it’s going down, they’re not going to allow take.”

Disappointed divers

Arcata diver Brandi Easter, the Alliance vice president and a volunteer with Reef Check’s Northern California organization, participated in the yearlong effort to develop the guidelines.

She said she understands that there’s “some shell shock” in the diving community over the resulting timeframes.

And she understands the pain. But those who love the sport can choose to convert their passion to stewardship of the resource, stepping back and giving nature time to rebound.

“I’ve been an ab diver for 25 years,” said Easter, 57. “That culture, unfortunately, that door has closed. We’re going to have a different culture. People are still wanting to hold on to what was, instead of looking forward.”

In the meantime, the Watermen’s Alliance has led large-scale urchin removal projects by recreational divers at various coves on the North Coast, principally in Mendocino County, over the past two years to see if clearing areas might aid the recovery of kelp.

Culling urchins

The state Ocean Protection Council just approved $500,000 for additional urchin culling this year under emergency regulations approved by the Fish and Game Commission at three locations, including Noyo Harbor, Portuguese Beach near the Mendocino Headlands and Caspar Cove. The first two locations will be targeted using commercial red urchin divers; the latter, with an army of volunteers, including sport divers, kayakers and others on the ocean surface providing support, and with still others onshore.

New authorization will allow divers to crush the purple urchins in place at Caspar Cove, and Reef Check will be organizing group efforts, with a schedule forthcoming. Russo said it’s his plan to get lots of people out.

“Two years into the project, and we’re still getting volunteers to show up in numbers,” Russo said. “The last removal event we had was huge. I think we had 50 divers and 20 kayakers and a bunch of people on shore.

“It’s satisfying. I was talking to someone the other day about how this whole project has been divers’ opportunity to get in and make a difference … and see the difference they’re making.”

You can reach Staff Writer Mary Callahan at 707-521-5249 or On Twitter @MaryCallahanB.

How To Get Involved

Fish and Wildlife Commission's Marine Resources Committee meeting:

9 a.m., Tuesday

Joseph A. Rattigan Building

Conference Room 410, 4th Floor

50 D Street, Santa Rosa

To participate via webinar go to

To participate via teleconference, call 877-402-9753 or 636-651-3141; access code 832 4310.

Go to to download a summary of the Recreational Abalone Fishery Management Plan

Mary Callahan

Environment and Climate Change, The Press Democrat

I am in awe of the breathtaking nature here in Sonoma County and am so grateful to live in this spectacular region we call home. I am amazed, too, by the expertise in our community and by the commitment to protecting the land, its waterways, its wildlife and its residents. My goal is to improve understanding of the issues, to find hope and to help all of us navigate the future of our environment. 

UPDATED: Please read and follow our commenting policy:

  • This is a family newspaper, please use a kind and respectful tone.
  • No profanity, hate speech or personal attacks. No off-topic remarks.
  • No disinformation about current events.
  • We will remove any comments — or commenters — that do not follow this commenting policy.
Send a letter to the editor

Our Network

The Press Democrat
Sonoma Index-Tribune
Petaluma Argus Courier
North Bay Business Journal
Sonoma Magazine
Bite Club Eats
La Prensa Sonoma
Sonoma County Gazette