Thursday, December 22, 2022

WILL WE OVERFISH STRIPED BASS IN 2022?

 

Most striped bass anglers were surprised, and many were openly skeptical, when a stock assessment update released last October revealed that there was a 78.6% probability that the striped bass spawning stock biomass would be rebuilt to its target level by 2029 with no change to current regulations, provided that fishing mortality did not rise above its 2021 level.

Even if the fishing mortality rate increased from 0.14, its 2021 level, to the target rate of 0.17, the rebuilding probability would still be 52%, making rebuilding more likely than not.  But if fishing mortality rose above that, and particularly if it rose above the 0.21 threshold, which signals that overfishing has occurred, timely rebuilding became increasingly unlikely.

Over all, the assessment update brought good news, first because it found that rebuilding by 2029, without the need to impose draconian management measures, was possible, and second because it made it clear that, if fishing mortality could be constrained at or below the target level, such rebuilding was likely.

However, as many anglers quickly noted, keeping fishing mortality at or below target, particularly with the large 2015 year class now bracketed by the 28- to 35-inch slot limit, might be very hard to do.  Angler effort is typically driven by striped bass abundance, and with the abundant 2015s being caught all along the striper coast, effort-driven mortality is likely to increase.

At last month’s meeting of the Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Management Board, Dr. Michael Armstrong, the Massachusetts fishery manager, expressed concern that the assessment update’s prediction—that the striped bass had a 78.6% chance of being rebuilt by 2023—wasn’t realistic, because the fishing mortality rate wouldn’t remain at 0.14.  He noted that recreational striped bass landings for the first eight months of 2022 were substantially higher than landings in 2021.  He warned,

“I want the Board to be conscious…It doesn’t take a lot to change the course of the recovery.”

Emerson Hasbrouck, the Governor’s Appointee from New York, observed that

“We’re getting close to being on the razor’s edge here,”

and asked whether there would be another stock assessment update presented in 2023.  

His question set off a brief discussion, which resulted in Toni Kearns, the Interstate Fishery Management Program Director for the ASMFC, stating that there weren’t sufficient resources available to prepare such an update; the necessary persons were “at or more than at” their full capacity, and in order to perform a new striped bass assessment update, another scheduled assessment would have to be delayed.

Having said that, Ms. Kearns noted that, while a lack of additional capacity prevented the ASMFC from performing assessment update in 2023, it should be able to determine whether the volume of fish actually removed from the striped bass stock in 2022 roughly equaled the removals predicted by the population model.  Mr. Hasbrouck expressed support for such an approach.

Dr. Armstrong, however, was not completely convinced.  He suggested that

“This is a billion dollar fishery.  Maybe instead of a spot assessment, striped bass is the one we should do.”

He then pointed out the biggest flaw in past striped bass management efforts, that

“we never hit our target [fishing mortality rate], at least for any amount of time.”

Facts support Dr. Armstrong’s concerns.  Addendum IV to Amendment 6 to the Atlantic Striped Bass Interstate Fishery Management Plan, adopted in 2014, saw the fishing mortality rate drop below its target level in 2015, but increase in subsequent years.  Addendum VI to Amendment 6 to the Atlantic Striped Bass Interstate Fishery Management Plan, adopted in 2019, reduced fishing mortality in 2020, but saw such mortality increase in the ocean, but not in the Chesapeake Bay, in 2021.

Addendum VI’s management measures remain in effect, and permitted a substantial increase in 2022 landings.

Not every Management Board member shared Dr. Armstrong’s concern.  Steven Train, the Governor’s Appointee from Maine, advised that the Management Board should trust the science behind the stock assessment’s projections, and asked rhetorically,

“How much damage can we do if we let this go for another year?”

Tom Fote, the Governor’s Appointee from New Jersey, is usually quick to question scientific conclusions, and predict that they will prove to be wrong after a few years have passed, but he broke that mold in last month’s discussion, saying

“I’ve been sitting around the table for a long time; we always say that we have to trust the science…I’m satisfied…I agree with the stock assessment.”

Which, in the end, wasn’t surprising, for in this case, "the science" supported maintaining the current management measures; a new stock assessment might call for additional restrictions, and Fote has always been consistent in one regard—he supports whatever management action might allow New Jersey anglers to kill more striped bass.

Dr. Armstrong responded to both comments, addressing Mr. Train by saying,

“I don’t criticize science, but we have empirical evidence”

of sharply increased landings.  Such comment was very much to the point, as the assessment update, which found a 78.6% chance of rebuilding the stock by 2029, was predicated on the fishing mortality rate remaining at 0.14, not at the apparently higher level occurring in 2022.

Dr. Armstrong also reiterated his earlier statement:

“To Tom Fote’s point, we’ve failed time and time again because we did not hit the target [fishing mortality rate].”

He seemed to have made his point, since the Management Board and ASMFC staff agreed that the Atlantic Striped Bass Technical Committee would, once the Marine Recreational Information Program estimates for 2022 were completed, compare actual removals with the model’s projections, and provide a report at the May 2023 Board meeting.

If excess fishing mortality is revealed in May, work on additional fishery management measures could begin.

Right now, 2022 estimates of recreational striped bass effort, harvest, and releases are only available for the first ten months of the year.

What do they tell us so far?

First, striped bass fishing effort has increased substantially.  Anglers took slightly over 16,000,000 trips primarily targeting striped bass through the end of October 2022, compared to just 12,800,00 trips during the same period of 2021.

Striped bass harvest showed a far sharper increase, going from about 1,200,000 fish in the first 10 months of 2021 to more than 2,500,000 by October 31, 2022.  In fact, the number of striped bass harvested by anglers in the first 10 months of 2022 far exceeded the 1,840,000 fish landed in all of 2021—and the last two months of 2022 saw very substantial striped bass fishing activity in southern New England and the New York Bight.  It would not be surprising to see final 2022 landings approach or exceed 3 million fish.

But recreational striped bass fishing mortality is not all about harvest; fish that die after release often comprise an even greater number of removals.  In that respect, the 2022 story is just a little different.

During the first 10 months of 2021, anglers released just under 22,500,000 striped bass; for the same period in 2022, that number fell to a little less than 19,750,000; using the currently accepted 9% release mortality rate, that equates to a little over 2,025,000 additional removals through October 31, 2021, and a little over 1,775,000 additional removals through October 31, 2022.

Add release mortality to the harvest, and we end up with roughly 3,225,000 striped bass removals for the first 10 months of 2021, compared to 4,275,000 removals—nearly 1,000,000 more—for the first 10 months of 2022.

That’s substantial.

Harvest and release estimates for the last two months of 2022 won’t be available until February, so it will be a while before managers know what overall 2022 fishing mortality will be.  In addition, the fishing mortality figure represents a rate of removals, so an increase in removals don’t necessarily indicate a corresponding increase in fishing mortality; if the spawning stock biomass is also increasing, as it is in the case with striped bass, the change in the fishing mortality rate will also depend on the rate of biomass increase.

Still, removals increased more than 30% between October 31, 2021 and the same time this year; the biomass clearly didn’t increase that much.  Thus, it is virtually certain that the fishing mortality rate for 2022 will be substantially greater than 0.14, and it is very, very possible that it will also exceed the 0.17 target.

Will it also exceed the 0.21 threshold, and trip a management trigger in the newly adopted Amendment 7 to the Interstate Fishery Management Plan for Atlantic Striped Bass?

Without the November/December data, I don’t want to predict that right now.  However, I will predict that discussions at the May 2023 Management Board meeting will prove extremely interesting, and might well determine the long-term health of the bass.

 

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