After a sudden decline in the stock last year, federal managers have officially designated Bering Sea snow crab as overfished and are working on a plan to rebuild the stock.

In October, the National Marine Fisheries Service determined that with its current low numbers, the stock of Bering Sea snow crab — also known as opilio crab — is officially overfished. That means that there is not enough mature male biomass to reach what’s considered the minimum stock size to be a sustainable fishery. As of the most recent survey, mature male biomass was estimated at 50,600 metric tons, which is significantly below the minimum threshold of 76,700 metric tons.

However, the stock is “not subject to overfishing,” according to a report submitted to the North Pacific Fishery Management Council on the issue. That’s because the fishery removals aren’t above the level considered to be sustainable — rather, it’s because the stock dropped for other reasons that scientists and managers aren’t entire sure of yet.

By regulation under the Magnuson-Stevens Fishery Conservation and Management Act, the council is required to develop a stock rebuilding plan in the meantime. Stock rebuilding plans are designed to set out a plan to bring a stock back to sustainable levels within a reasonable timeframe while taking the effects on communities, treaties, and marine ecosystems into consideration. Any rebuilding plan would be incorporated into the fishery management plan.

The implementation of a plan doesn’t necessarily lead to restrictions in other fisheries, although it may, according to the report.

The council has considered a rebuilding plan for snow crab once before, in 2010, said Diana Stram, council staff who works with the Crab Plan Team. However, the stock rebounded, and the plan didn’t have to go into place. This time the stock is at its lowest numbers ever, but scientists are hopeful that this stock will recover, unlike some of the others, Stram said.

Researchers compiling the survey data in the fall found that female crab numbers had dropped approximately 99 percent from the previous year along with a substantial drop in males. At the time, they said there were two options: either the crab are alive and the survey completely missed them, which researchers said was unlikely, or the crab are dead. If they are dead, there are a variety of potential causes, including predation by Pacific cod and bitter crab syndrome, among others. Stram said it’s increasingly seeming that the crab are dead.

Fishing can also lead to unobserved mortality, according to the update to the council.

“Unobserved mortality can also occur when crab is impacted by, but not captured in fishing gear,” the report states. “For instance, crab may actively escape capture from trawl gear, as they can slip under the trawl itself, or over the sweeps, but the damage from the gear results in mortality or delayed mortality due to injuries. The potential for unobserved mortality of crabs that encounter bottom trawls but are not captured has long been a concern for the management of groundfish fisheries in the Bering Sea It is not accounted for in crab stock assessments.”

The rebuilding plan would take that uncertainty into account and would set up a timeframe with maximum and minimum times. At minimum, the stock would need to meet the minimum threshold for at least one year to be considered rebuilt; at max, it will probably be set at 10 years or so, Stram said. If the stock doesn’t recover within that time, the council can revisit the plan and make adjustments as necessary.

Several other crab stocks in the Bering Sea are already under rebuilding plans, including the St. Matthew Island blue king crab and the Pribilof Islands blue king crab. Some, like St. Matthew Island, have been under rebuilding plans with no fishing allowed for many years. However, there is some difference between between that stock and the Bering Sea snow crab, Stram said, and the scientists expect the snow crab to be able to make a recovery. One difference is that the blue king crab declined steadily for years; snow crab, on the other hand, showed some increases within the last five years.

The crabbers themselves have expressed some skepticism about the results of the surveys because they are finding crab on the fishing grounds. Jamie Goen, the executive director of the Alaska Bering Sea Crabber’s Association, said the fleet recognizes that the survey results are the best science available, but that the crabbing season is going relatively well with the fishermen encountering snow crab on the grounds.

The crab fishing quotas were cut significantly in light of the reduced crab stocks; Goen said the fleet estimated the loss in revenue at more than $200 million. With a stock rebuilding plan to go into place, it will likely mean reduced fishing for the life of the plan as managers try to rebuild the stock.

Goen noted that there are options to allow the fleet to continue fishing under a plan, but it depends on what the data says about the minimum time for the stock to rebuild to the minimum threshold.

Stram said the scientists are still working on the data necessary to provide the council with all the necessary information to build the rebuilding plan, so the information provided for the February meeting is an update. The council won’t take action until at least May or June, when the data is scheduled to be more complete.

The Crab Plan Team and Scientific and Statistical Committee meet this week, and the council is scheduled to begin meeting Feb 7.

[Meanwhile, the 2022 Bering Sea “pre-approved” snow crab bycatch level by trawlers is 5.99 million crab which equals nearly 7.8 million pounds. The catch quota for crabbers is 5.6 million pounds.]