ICCAT INCREASES WESTERN ATLANTIC BLUEFIN QUOTA, TO MIXED REVIEWS

 

The recreational fishing community was generally unhappy with this year’s early closure of the bluefin tuna fishery.  The recreational fishing industry—both the for-hire fleet and the fishing tackle purveyors—were particularly upset, with many calling for an increase in the United States’ quota of western Atlantic bluefin tuna.  When the closure occurred, such increase seemed unlikely, as no other nation was likely to yield part of its own quota to the United States.  As I noted at the time,

“About the best we can hope for is that, when a new stock assessment is released in 2026 or 2027, it will suggest that everyone’s quotas can be increased, and that such rising tide will float the United States’ anglers’ boat along with everyone else’s.”

However, in writing that, I didn’t consider another possibility: that even though a new stock assessment has not yet been released, other scientific work might be used to justify a quota increase.

That is what happened this year.

Dr. Walter Golet is an Associate Professor at the University of Maine, who serves as the Lead Principal Investigator at the Pelagic Fisheries Lab at the university’s School of Marine Sciences, where he has done extensive work researching Atlantic bluefin tuna.  His expertise has resulted in him heading up the United States’ ICCAT Advisory Committee; he also sits on the National Marine Fisheries Service’s Highly Migratory Species Advisory Panel, where I have an opportunity to meet him and have some brief conversations about various fisheries issues.

One of the projects that his team is working on is something they call “Genetics for Giants and Juvies,” a cooperative research project that employs recreational and commercial fishermen willing to provide fin clips from the bluefin tuna that they catch.  The project involves something called “Close-Kin Mark Recapture,” which the lab describes as

“a new technique used to determine the ratio of genetically matched fish to larvae (i.e. parent-offspring pairs or POPs).  In other words, we are using DNA to map out the family tree of [Atlantic bluefin tuna] in the Western Atlantic!”

The lab goes on to say that using the new technique,

“we can estimate where the fish come from (Western or Eastern stock), the absolute population abundance, and the future productivity of the stock.  This information will provide managers with more accurate and real-time data to sustainably manage the Atlantic bluefin fishery!”

(As an aside, active bluefin fishermen who might like to assist Dr. Golet with his work can sign up at the project webpage, which can be found at https://umaine.edu/pelagicfisherieslab/2025/06/05/genetics-for-giants-juvies/).

Each year, the International Commission for the Conservation of Atlantic Tunas holds its regular meeting in November.  Well before that occurs, sometime during the spring and summer, the various “species groups” hold what ICCAT deems “intersessional meetings,” where biologists review scientific information regarding the various ICCAT-managed species.  At last April’s intersessional meeting for the Bluefin Tuna Species Group, Close-Kin Mark-Recapture data was considered for the first time.

The data didn’t result in any startling new revelations.  It’s estimate for the size of the western Atlantic bluefin population fell within the range or earlier estimates, although it was toward the higher end of that range.  As noted in the report of the intersessional meeting,

“Overall, the [western Atlantic bluefin tuna close-kin mark recapture] study analyzed approximately 9000 adults from the West Atlantic mixed fisheries paired with [about] 4000 larvae from the Gulf of Mexico western spawning area, and found 56 parent-offspring matches, which provided estimates of spawner detection probability in the US and Canadian fisheries, and in turn, an estimate of the absolute abundance of the western spawning population for 2018.

“The analysts explained that the [western Atlantic bluefin tuna close-kin mark recapture] analysis provided an abundance estimate of adults age 8+ potentially spawning in the West Atlantic, either Gulf of Mexico (GOM) or other areas, including the Slope Sea…

“The [Close-Kin Mark Recapture] model formally estimates a quantity known as Total Reproductive Output (TRO), which is not strictly comparable to estimates from the operating models (OMs).  The TRO was converted to a comparable metric of spawning stock biomass (SSB) using known age structure and the total biomass of all fish age 8+.

“The Group initially saw a comparison of [close-kin mark recapture] SSB with the actual spawning biomass from the OMs.  During the meeting the actual biomass of age 8+ fish was extracted from the OMs.  The Group discussed the comparison shown between the estimate of SSB in 2028 obtained from the [close-kin mark recapture] analysis (21 kt with a CV-0.19) with the 48 values of SSB in 2018 corresponding to the OMs used in the Management Strategy Evaluation (MSE).  Although the SSB estimate from [the western Atlantic bluefin tuna close-kin mark recapture] is inside the range of values from the OMs, its value is larger than the majority of values from the OMs.  Despite this difference, the Group noted that a major benefit is that the [close-kin mark recapture] results can considerably reduce the spread of uncertainty in population scale (the most influential axis of uncertainty in the MSE) with respect to what was assumed in the OMs...”

Thus, it seemed that, while the close-kin mark recapture data suggested that the size of the western Atlantic bluefin tuna population probably did fall within the range of previous estimates, it also served to narrow that range of estimates, presumably eliminating some estimates from the lower end of the range.

But there was still a question of what to do with the data.

In 2022, ICCAT had adopted a Management Procedure for Atlantic bluefin tuna which, complementing the Management Strategy Evaluation adopted in the same year, was intended to automatically calculate the total allowable catch for both the eastern and western stocks, requiring that such TAC be set at a level that had at least a 60% probability that the stock would neither become overfished nor be subject to overfishing.  The Management Procedure specifies that the total allowable catch be calculated by removing a fixed proportion of the bluefin from each of the East or West areas, with overall abundance of bluefin in each area being estimated based on a weighted average of each abundance index that exists for the relevant area.

Based on such calculations, the western Atlantic bluefin tuna quotas for 2026, 2027, and 2028 would probably be substantially the same as they were for the three previous years.

However, the Management Procedure also includes the concept of “exceptional circumstances,” which might occur if

“there is evidence that the stock and/or fishery dynamics are in states not previously considered to be plausible in the context of the management strategy evaluation,…there is evidence that the data required to apply the management procedure are not available or sufficient, or are no longer appropriate, and/or…there is evidence that the total catch for either the West area or the East area is above the total allowable catch for the respective area set using the [management procedure].  [formatting and internal references omitted]”

If one or more exceptional circumstances exist, the total allowable catch calculated by application of the Management Procedure might still be adopted, but if the

“[Standing Committee on Research and Statistics] determines that [the exceptional circumstance or circumstances] precludes the application of the [Management Procedure] or makes the application of the [Management Procedure] or the implementation of its results (i.e., TACs) unadvisable,”

alternative management options may be adopted.

So the question became:  Do the results of the Close-Kin Mark Recapture study rise to the level of an exceptional circumstance?

At last April’s Bluefin Tuna Study Group intersessional meeting, opinions on that were split.

“While the Group agreed [the western Atlantic bluefin close-kin mark recapture study] was a large step forward in the knowledge of the scale of the western stock, the Group struggled to reach consensus on if this new information fell within the definition of [exceptional circumstances]…Some participants felt the [western Atlantic bluefin tuna close-kin mark recapture] results were a large step forward in the knowledge of western scale and a substantially different understanding of stock scale compared to the assumptions incorporated in the 2022 [Management Strategy Evaluation] results.  Others felt that while the [close-kin mark recapture study] was a solid new piece of information, the results were not beyond anything seen in the full range of the 2022 [Operating Models] results and, therefore, they did not consider that these new [close-kin mark recapture] results warranted triggering [exceptional circumstances.”

But, in the end, after what ICCAT characterized as “long and intense discussions” at the recently-concluded meeting, the Commission agreed to increase the western Atlantic bluefin tuna quota by 17%, to 3,081.6 metric tons, for the period 2026-2028.  That would increase the United States quota from 1,316.14 metric tons during the period 2023-2025 to 1,490.38 metric tons, plus an additional bycatch allowance for longline vessels fishing near the boundary delineating the eastern and western management areas, for the period 2026-2028.

While some fishing industry organizations expressed low-key approval of that outcome, more conservation-focused organizations criticized both the decision and how it was reached.

A post on the website Harveststrategies.org, which is supported by multiple conservation organizations, voiced concern that, after

“ICCAT scientists could not agree on whether the new [close-kin mark recapture] information constituted an official exceptional circumstance…[they] did a light revision of the [Management Strategy Evaluation] and subsequently updated the original [Management Procedure], providing two separate [Management Procedures] and associated TACs to the Commission as the scientific advice—BR, the officially adopted [Management Procedure], and BR*, the new revised [Management Procedure].

“This unfortunately opened the door to extensive negotiations…on the [Management Procedure] and how to implement it.  After days of debate on 10 separate formal proposals, ICCAT ended by continuing to operate under the originally adopted BR [Management Procedure], but with incomplete implementation…[I]n the West, the new measure sets a TAC 20% higher than allowed under the originally implemented [Management Procedure], with an extra 100 [metric ton] from the East to the West to use for bycatch in the vicinity of the West/East management boundary.  The final TAC represents a 17% increase in the western TAC, counter to the [Management Procedure].

“This is not how the [Management Procedure] process is supposed to work.  First, the [exceptional circumstances protocol] for Atlantic bluefin tuna is very clear.  The first step is to answer the question, ‘Is there evidence of an exceptional circumstance?’  If the answer is yes, then further investigations should be considered, such as revising the [Management Procedure].  But ICCAT scientists did the revision before first answering the question…Thankfully, there is [a Management Procedure] review scheduled for the next few years that provides an opportunity to get back on course with a bluefin [Management Procedure] that is likely to achieve Commission objectives.”

The World Wildlife Fund was more sharply critical, complaining that

“WWF hailed the 2022 adoption of the Management Procedure for Atlantic bluefin tuna as a landmark achievement—a science-based tool designed to both secure the long-term sustainability of stocks and to showcase the Atlantic bluefin tuna as an ICCAT success story.  Yet, just after completing the first management cycle, it is deeply disappointing to see political pressure overriding and threatening to compromise science-based, sustainable management.  We strongly believe that deviating from the agreed management framework—developed through such an extensive and resource-intensive process—would set a negative example potentially undermining the future governance of other stocks managed under this Convention.”

And that may be the real lesson to be taken from ICCAT’s recent action.

Right now, there seem to be a lot of bluefin tuna in the western Atlantic.  East Coast anglers caught their bluefin quota so quickly last year precisely because there were a lot of fish available for them to catch.

That wasn’t true a couple of decades ago, when bluefin were much harder to come by.  It was only thanks to concerted, international action that the western Atlantic bluefin population began to rebuild.

ICCAT’s decision to increase the bluefin tuna quota for the next three-year period was less an affront to the bluefin—the fish are abundant enough, and the increase was small enough, that it probably won’t do significant harm to the stock before remedial action can be taken—than to the management process itself.

Because, whether the species in question is bluefin tuna, striped bass, or something else, once managers begin to ignore their established management protocols, and instead either sidestep them, or use dubious excuses to create exceptions to the established rules when an opportunity to increase yield arises, then discipline is lost, and it becomes ever easier to sidestep the management process again.

Hopefully, Dr. Golet’s data, which suggests that western Atlantic bluefin are somewhat more abundant than previously believed, will prove to be correct, and the tuna will suffer no harm at all.

And hopefully, the lax process used to increase the western Atlantic bluefin quota for the upcoming three years, and the criticism that laxness engendered will serve as a warning to ICCAT to be more hesitant to amend an established procedure again, just because it seems to be the politically popular thing to do.