“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.
“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.
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.
“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.