Major crab harvests down again, Tanners reopen
Biologists had some less-than-stellar news about Alaska’s crab fisheries this month: surveys have shown that several species’ biomass have declined in the past year, although Tanner crab are on the rebound compared to past years.
Last year, the big crab harvests — Bristol Bay red king crab, along with Tanner and snow crabs — were all cut, with Tanners closed completely, due to concerns about the amount showing up in surveys. So this year’s news was not out of the blue, and the reopening of the Tanner crab fishery was an upshot.
The bottom line is that this year, unlike last, those three big crab fisheries will all open this year. But the quota for Bristol Bay red king crab and Bering Sea snow crab is down compared to the year prior.
That’s all largely the result of the survey and modeling work during 2017, which was explained in detail at the North Pacific Fishery Management Council annual update in October. The season began Oct. 15.
The council heard the Bering Sea and Aleutian Islands Crab Stock Assessment at its October meeting, including reports that both snow crab and Bristol Bay red king crab stocks have declined in the past year. Norton Sound red king crab and Saint Matthew blue king crab stocks have also declined, while Tanner crab is thought to have increased in the past year.
That news, and the Crab Plan Team’s recommendation, prompted the council to adopt a harvest lower than what was biologically allowed, to account for the unknown declines of those stocks. Each stock received a buffer of between 10 percent and 25 percent, with a larger buffer for the Western Aleutian Islands red king crab stock.
While the council sets the overfishing limit, or OFL, and acceptable biological catch, or ABC, based on each stock assessment and information, the final catch limit, or TAC, is set by the Alaska Department of Fish and Game, which could decide on more conservative management, depending on how the most recent numbers are perceived.
For Bristol Bay red King crab, the Alaska Department of Fish and Game, which jointly manages the federal crab fisheries with the council, opted to set the total allowable catch, or TAC, at 6.6 million pounds, with the majority (5.94 million pounds) going to the and 10 percent, or, 660,1000 pounds, for the Community Development Quota entity fishery. That’s a decline from the year prior, and lowest in at least 20 years.
The Bering Sea snow crab quota is also a decline from the year prior, at about 18.9 million pounds. The Tanner crab fishery is open in the western district, with a quota of about 2.2 million pounds, while the eastern district is closed.
The Pribilof District red and blue king crab fisheries are closed next year, as is the Saint Matthew Island section of the blue king crab fishery.
For Bristol Bay red king crab, the crab plan team recommended an OFL of 5,600 tons from which the ABC, was derived at 5,040 tons, using a 10 percent buffer, which the Scientific and Statistical Committee also recommended and the council ultimately adopted.
A 20 percent buffer was used for snow crab, which was a larger buffer than last year, when the scientists recommended a 10 percent buffer, meant to account for so much more uncertainty in the stock.
But Tanner crab was a brighter spot in the stock assessments. The fishery was closed in 2017 due to low abundance shown in surveys, although fishermen said they were still seeing them on the grounds. This year, the Crab Plan Team modeling did show an uptick in that stock.
As a result, the OFL was set at 25,420 tons and the ABC at 20,330 tons.
Some of the issues with the crab stocks were attributed to issues with the models fitting correctly, and accounting for certain data in the past. Now, they are looking at alternatives.
Scientists have had trouble with the stock assessment model fitting the data in recent years, in part because of a drop that doesn’t match very well.
During the council’s October presentation, they heard that one of the issues is that once there is a steep decline, it’s hard to account for that again.