IPHC staff present grim halibut stock assessement
Halibut fishermen are bracing for another huge quota cut after the International Pacific Halibut Commission staff presented a rather grim stock assessment at their interim meeting in Seattle last week.
While there is no longer a “staff recommendation,” staff members do present a decision table with a “blue line” that is essentially the same thing: a harvest level at which the fishery should not diminish too much further in the future.
For 2014, the blue line came in at a coast-wide quota, from California to the Bering Sea, of 24.45 million pounds, down 21 percent from 2013.
For Alaska, the state-wide quota would be 18.74 million pounds, but after subtracting wastage and guided sport use in areas 2C and 3A under the new catch sharing plan, the amount left for commercial harvest would be 15.79 million pounds.
Broken down by area, the statewide commercial harvest quota would look like this:
Area 2C, Southeast: 3.32 million pounds, the only area to see an increase, up from 2.97 million pounds in 2013;
Area 3A, Central Gulf of Alaska: 7.32 million pounds, down from 11.03 million;
Area 3B, Western Gulf of Alaska: 2.84 million pounds, down from 4.29 million;
Area 4A, Eastern Aleutians: 850,000 pounds, down from 1.33 million;
Area 4B, Western Aleutians: 820,000 pounds, down from 1.16 million; and
Area 4CDE, Bering Sea: 640,000 pounds, down from 1.03 million.
For Area 2C, wastage would be figured at 80,000 pounds, and 760,000 pounds would be set aside for the charter fleet, bringing that total to 4.16 million pounds. In Area 3A, 330,000 pounds is figured for wastage and 1.78 million pounds would be set aside for the charter fleet, bringing that total to 9.43 million pounds.
At the interim meeting for the 2013 season, the blue line was pointing to a much larger decrease than was adopted by the commission at the annual meeting, with a recommendation for Area 3A of 9.24 million pounds, below even what the recommendation is for 2014, but the commission cut less than a million pounds from that area.
Similar steps were taken in Area 3B, where the blue line suggested a quota of 2.73 million pounds, but the commission only took off about 750,000 pounds.
The coast-wide recommendation at last year’s interim meeting was for a state-wide commercial harvest of 17.41 million pounds, below the state-wide recommendation for this year but before the catch sharing plan with the charter fleet was in place.
It is impossible to say what the commission will do this time, but with the blue line continuing to show the need for drastic measures, it is certain that a substantial cut in quota should be expected.
Part of the problem is that size at age continues to fall, with the fish simply not growing as fast as in the past, and part of the problem is years of chronic overestimation of the stocks leading to over-harvest, what is known as retrospective bias.
Essentially, fish that the numbers said should be there were not showing up in the surveys, and the problem did not get fully recognized and corrected for until a couple of years ago.
Also, there were some large year classes in the late 1980’s and early 1990’s that have aged out of the fishery, and no similar stocks have followed.
IPHC staff have been known for changing models used to gauge fishery health on a regular basis, with each model telling them something different, with three different models used in the past few years.
However, this year’s interim meeting brought a change in attitude about that.
Now, staff is going to use all three.
Ian Stewart, quantitative scientist and forecaster for the IPHC, addressed the issue.
“The trouble is that we’ve had variable estimates over time,” Stewart said. “We’ve improved our methods, and that’s a good thing, but we’ve had variability in the estimates, and in the catch advice, and unfortunately in the confidence levels in the various estimates, because when things change, it takes awhile to get used to them.”
He said that it seemed at times that they had lost sight of the goal, which is understanding the stock, not necessarily searching for the “perfect” assessment model.
He told IPHC executive director Bruce Lehman that there is no perfect model, and he would not be able to provide him with one.
“But it’s okay,” he said, “in fact, it’s a big step forward to realize that this isn’t a modeling exercise. The point is we’re trying to understand what’s going on with the stock.”
He likened the new method to what hurricane forecasters do.
“Fortunately there’s a field that’s already figured this out,” he said.
Hurricane forecasters use “ensemble modeling,” which is why they show so many possibilities for a hurricane track.
The example he used was a hurricane south of Cuba that could possibly hit Washington, D.C., Newfoundland or Bermuda. If you live in one of those areas, you want to know that there is some chance that the hurricane could visit your area.
In the long run, he said, “you’re just trying to get a perspective of what’s really going on?”
The advantage of ensemble modeling is that the areas where the different models overlap, or predict the same outcome, reduces the uncertainty, and the outliers are more obvious.
He said the IPHC could really lead from the front on this issue, because this method could be helpful in a lot of other fisheries as well.
Stewart said that the signs are that incoming recruitment into the fishery is likely to be low, either flat or even declining more, but that as the biomass stabilizes at those lower levels, stock response to management may increase, so that a cut in quota will lead to a fairly immediate rise in biomass.
The full audio accompanied by the slides as presented during the two days of meetings, as well as a report on management strategy evaluation, and reports from halibut bycatch group, management strategy advisory board and numerous other documents, can be found at http://www.iphc.int/meetings-and-events/interim-meeting.html.
The annual meeting takes place Jan. 13 through 17 at the Grand Hyatt hotel in Seattle. Attendees can get a reduced rate if they make reservations by Dec. 23.
Cristy Fry has commercial fished out of Homer and King Cove since 1978. She can be reached at firstname.lastname@example.org.
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