SEAFOODNEWS.COM by John Sackton and Peggy Parker – August 30, 2016
The summer survey results have not been good for either Bering Sea snow (opilio) or tanner (Bairdi) crab. For 2015-16, snow crab landings from both the IFQ and CDQ fisheries were 40.61 million pounds, a 40% cut from 67.9 million lbs in 2014-15. For Bairdi the 2015-16 quota was 19.64 million pounds, which helped make up some of the shortfall.
But the snow crab market reacted quickly to the cut in Alaskan snow crab, and prices rose throughout the year, including when Canada’s larger fishery opened. Industry participants think 2016-17 may be worse.
This has now been confirmed with the raw survey data just released by Dr. Bob Foy of the Kodiak Fisheries Science Laboratory showing that legal male biomass has declined in all of the major crab fisheries.
Legal male biomass in the crab fisheries declined across the board, with the largest declines in Opilio. The survey also measures the abundance of female crabs; all these numbers go into determining appropriate fishing levels.
The process from raw survey data to final catch quotas is complicated and includes lengthy scrutiny against both federal and state guidelines.
The bottom line is whether the analysis of the survey numbers shows there is a sufficient stock to meet the trigger thresholds for the State of Alaska to open the season for both opilio and bairdi.
“Thresholds for each of the [crab] fishery stocks are contained in state regulations,” explained Ruth Christiansen, science advisor to the Alaska Bering Sea Crabbers Association.
The threshold formula is based on spawning biomass (stock size of mature males and females). However, Alaska’s crab managers have three data sets to work with, and can pick one or use a combination to determine their estimates of spawning biomass. The data sets each differ slightly in how the raw survey data is interpreted and modeled to produce the biomass numbers.
“There are multiple considerations going into how they chose one or a combination of the three options,” Christiansen said.
The survey numbers that were released today will go to NMFS stock assessment team to input the raw data into the stock assessment model.
“There is one baseline model,” explains Christiansen, “but the authors make adjustments to come up with different versions of the model.
“Those versions are then given to the Crab Plan Team, who meet September 20-23 and make model recommendations for each of the crab stocks,” she said.
That process includes setting an over fishing limit (OFL) and allowable biological catch (ABC).
The state crab managers work with these numbers to determine a minimum threshold for opening the fishery.
Meanwhile, the model recommendations get another peer reveiw from the Science and Statistical Committee of the North Pacific Council, who meets October 3-5.
So ADF&G’s final announcement for the fall season will be made October 6-7, predicts Christiansen. If the state’s minimum threshold of population has not been met, both the Opilio and Bairdi fishery will remain closed.
If the fishery is opened, the TAC will very likely be lower than in 2016.
This past year, bairdi has made up to some extent for the lack of snow crab, and the fishery took 19.6 million pounds in 2015-16. However, bairdi numbers have been highly volatile, and the fishery was closed for four years between 2010 and 2013. Since then there have been steadily increasing stocks, until this year.
Crab recruitment takes years and depends on environmental conditions as well as mortality from predators. This means that in less favorable conditions, the minimum stock sizes may be lower as well, as the entire productivity of the fishery is down.
“This year, 2016, is one of hottest on record for water temperature,” said Christiansen. “Both sea surface temperatures and ocean floor. There are no cold pools anywhere, unlike 2012 when we saw one of the largest cold pools on record.”
The warming temperatures can make the environment less hospitable to crab populations, and the lack of cold pools can scatter populations, potentially impacting survey results as well.
The upshot is that the 2017 Alaska crab season for opilio and bairdi is looking difficult, and under the worst case scenarios, the two fisheries might not open at all.
Source: Draft NOAA Technical Memorandum Trawl Survey for Commercial Crab Species for 2016