Thursday, August 12, 2021

BLUEFISH: WHERE DO WE GO FROM HERE?

Last Monday, the Mid-Atlantic Fishery Management Council, along with the Atlantic States Marine Fisheries Commission’s Bluefish Management Board, met to establish bluefish specifications for the 2022 and 2023 fishing years.

Bluefish management has experienced a number of recent changes.  Perhaps most notable was the adoption of the Bluefish Reallocation and Rebuilding Amendment, which was adopted by both the Council and Management Board last June, and forwarded to the National Marine Fisheries Service for implementation.  The new amendment, which NMFS is expected to approve, is intended to rebuild the bluefish stock within 7 years.  It also increased the recreational bluefish allocation from 83% to 86% of overall landings, and made a number of other, technical changes to the bluefish management process.

The Rebuilding Amendment will be reflected in the 2022 and 2023 specifications.

The specifications will also reflect the results of a new operational stock assessment, released earlier this year, which essentially confirmed the findings of the 2019 operational assessment:  The bluefish stock is overfished, but is not currently subject to overfishing.  However, while there is no question that the stock is overfished, the spawning stock biomass is estimated to be only about 5% below the biomass threshold, which suggests that rebuilding it back to target within 7 years should be doable—so long as managers stick to the science, and don’t seek every opportunity to increase short-term landings at the expense of long-term abundance.

They already did that in 2019 when, instead of following established practice and basing predicted 2020 landings on average landings in the three preceding years, instead based them only on landings in 2018, which were the lowest in a time series extending back 35 years.  

While that prevented 2020 regulations from being made more restrictive than the current 3-fish bag limit (5 on for-hire vessels), it also allowed anglers to exceed their 2020 catch limit.  Thus, the recreational sector found itself snagged on the second prong of a classic “you can pay me now or you can pay me later” dilemma; since bluefish are currently overfished, anglers’ 2020 overharvest must be deducted, on a pound-for-pound basis, from the 2022 recreational catch limit.

The recreational sector will be required to pay back 3.65 million pounds of bluefish in 2022.  Fortunately for anglers, the real-world impact of that payback won’t be severe; the combination of a slightly increased recreational allocation and a slightly increased bluefish population means that even after the payback is made, the recreational harvest limit will be 13.89 million pounds, and slightly above the actual 2020 landings.

Thus, if 2021 landings are similar to 2020 landings during the first 8 (or possibly 10, depending on when data for September and October becomes available) months of this year, it is very likely that recreational regulations will remain unchanged next season.

Right now, it looks as if the recreational harvest limit will then make a big jump, to 22.14 million pounds, in 2023; such an increase, if it occurs, will undoubtedly lead to increased bag limits.  However, anglers who want to take home more bluefish probably shouldn’t be buying new chest freezers just yet.

That’s because the Council and Management Board decided to carry 2020 regulations over into 2021; assuming both angler effort and bluefish availability also remain constant, that means that anglers will probably overfish again this season, and thus will have to pay back another 4 million or so pounds of bluefish in 2023.  That would knock the recreational harvest limit back to something around 18 million pounds, which is still a significant increase, and should still lead to higher bag limits, although such limits won’t be as high as they would be if overfishing doesn't occur in 2021.

So, based on what happened last Monday, are bluefish back on the path to renewed abundance and a rebuilt stock?

Maybe.

But maybe not.  Because there are many things playing out in the background that could impact the stock, for good or ill.  Just about all of them can be categorized as some form of either scientific or management uncertainty.

Although the 2015 benchmark stock assessment passed peer review, there were a number of issues that raised significant concerns.  After that assessment was released, the Mid-Atlantic Council’s Scientific and Statistical Committee stated that the most significant sources of scientific uncertainty related to the calculation of the overfishing limit and acceptable biological catch were,

“In order of importance:

·         Uncertainty in the stock recruitment relationship adds to uncertainty in appropriate reference points.

·         The uncertainty in MRIP sampling overall, which is the most influential data in the assessment.  Questions have been raised about the uncertainty in the historical MRFSS/MRIP estimates in general, and are particularly relevant here given the highly episodic nature of Bluefish catches in the recreational fisheries coast wide.

·         Approximately 60% of the population biomass is in the aggregated 6+ age group for which there is relatively little information.

·         The extent to which the MRIP index and MRIP catch are partially redundant in the assessment needs to be determined.

·         Commercial discards are assumed to be insignificant, which may not be the case.”

Six years have passed since the benchmark assessment was completed, and many of those issues remain outstanding; most were at least mentioned at last Monday’s meeting,

Other issues also give reason for pause. 

One is the apparent decline in bluefish catch per trip in the recreational fishery.

A bluefish trip is defined, for determining that value, as a trip that either targets bluefish, or on which a bluefish is caught.  Over the long term, anglers caught an average of 1.5 bluefish on each bluefish trip; in 2020, that number fell to about 1.0.  That would suggest lower abundance, leading to anglers encountering fewer bluefish, and provides cause for concern that the stock may be in even worse shape than the operational assessment suggests.

On the other hand, because a “bluefish trip” includes trips on which bluefish are caught, it could also reflect fewer anglers fishing in places and ways that are likely to yield bluefish bycatch, perhaps as a result of a decline in the abundance of striped bass, summer flounder, or other species.

Another, bigger issue is the difficulty biologists have in quantifying the magnitude of dead discards in the recreational fishery.

The bluefish fishery is somewhat unique, as it is one of the few major recreational fisheries that is not generally governed by a size limit (although some states, mainly in the South, have chosen to adopt one), and there is a big late summer/early fall fishery for young of the year “snapper” blues along much of the coast.  In addition, larger bluefish, particularly those feeding on menhaden, tend to have oilier, more strongly-flavored flesh than do smaller individuals that typically feed on sand eels, spearing, or similar “whitebait.”

As a result, the size of bluefish retained by anglers is strongly skewed to the smaller sizes; in 2019, the last year for which landings data was unaffected by COVID, just over 50% of the bluefish kept by anglers were between 11 and 14 inches long; another 23% of the fish kept fell into the 4- to 10-inch range.  Bluefish measuring 18 inches or more comprised only about 7.25% of the recreational harvest.

The big unknown is whether the bluefish that anglers release are the same size as the ones that they keep.  There is evidence that they may, in fact, be larger.  The 2015 stock assessment noted that

“Although they recruit to the fishery before they are fully mature, larger, older fish are considered unpalatable, reducing demand for those sizes in the commercial market and encouraging the release of those size classes in the recreational fishery.  [emphasis added]”

The assessment relied on information from four different sources, the American Littoral Society fish tagging program, and volunteer angler reporting programs in Connecticut, Rhode Island, and New Jersey, coming to the conclusion that

The average size of the recreationally released bluefish is larger than the average size of retained fish, an uncommon pattern most likely due to bluefish’s unpalatability at larger sizes.  [emphasis added]”

Anyone who has participated in the recreational bluefish fishery, and has spent any time talking with bluefish anglers, recognizes the truth of that statement.

Yet when the Mid-Atlantic Council and Management Board addressed the discard issue in 2019, they came to a very different result.  If they used the Northeast Fisheries Science Center’s calculation of bluefish that died after release, they would have had to deduct 9.9 million pounds of dead discards from the recreational catch limit, leaving a recreational harvest limit of just 3.62 million pounds, which would have been a huge drop from the 2019 harvest limit of 11.62 million pounds, and would have required extremely restrictive management measures to adequately constrain recreational harvest.

But they found a way around such a big cut in landings, because there were some problems with the Science Center’s estimate of dead discards.  The data it was based on were limited to northeastern states, and didn’t necessarily reflect what went on further south; in addition, the data itself were relatively sparse, as relatively few anglers took part in any of the four programs from which it was derived.  NMFS’ Greater Atlantic Regional Fisheries Office did not use the Science Center data, and instead just assumed that the size of the bluefish released was the same as the bluefish retained, an assumption that was almost certainly false.

Still, if the Council and Management Board adopted the GARFO assumption, rather than the Science Center’s data, they would only be required to deduct 4.03 million pounds for dead discards, which would allow them to set a recreational harvest limit of 9.48 million pounds, a limit more than 250% of the limit that resulted from the Science Center’s data.  Following their well-established principle that “the best available science is whatever lets us kill the most fish,” recreational representatives on both the Council and Management Board strongly supported the adoption of the GARFO assumption, which has been used to calculate the recreational harvest limit ever since.

The difference between the GARFO assumption and the Science Center data continues to inject substantial uncertainty into bluefish management; in 2019, GARFO assumed that recreational release mortality was a mere 4.88 million pounds, compared to the Science Center's calculation of 15.41 million pounds.  In 2020, GARFO assumed release mortality to be slightly less, 4.19 million pounds while, probably due to COVID-limited data, the Science Center did not calculate such removals.

To get some idea of how the Science Center’s approach could impact recreational landings, assume that the Science Center’s 2020 calculation would have the same relationship to the GARFO assumption as it had in 2019, when such calculated mortality was about 3.16 times as large as GARFO assumption.  Multiplying the assumed 4.19 million pounds of dead discards by such amount would yield calculated dead discards of about 13.23 million pounds.  If you subtracted that amount, plus the payback for the 2020 overage, from the 2021 recreational catch limit, the 2021 recreational harvest limit would be 0.66 million pounds.

Instead of seeing its harvest limit increase, as is currently the case, there probably would have been no recreational bluefish landings permitted in 2022.

So how dead discards are calculated makes a very big difference.  If the GARFO assumptions are wrong, and the Science Center calculations reflect reality, anglers will inadvertently overharvest by about 9 million pounds next year.  While such overharvest would have no immediate regulatory impact, because it is currently authorized by the Council and Management Board, it certainly won’t help the already overfished stock to rebuild by its 2028 deadline.

It might not allow it to rebuild at all.

Thus, it would make sense to build some provision for management uncertainty into the 2022 specifications, but that’s not going to happen.

The Bluefish Monitoring Committee is aware of the issue, and intends to investigate ways to quantify the uncertainty and perhaps account for it in future specifications.  But it chose not to build any sort of buffer into its 2021 calculations.

The Monitoring Committee argued that, because it doesn’t know how to quantify the uncertainty, any buffer that it might propose would be arbitrary, and not based on solid scientific calculations.  That position was supported by Dr. Paul Rago of the Northeast Fisheries Science Center, who noted that it isn’t currently possible to scientifically determine the magnitude of the management uncertainty.

That is undoubtedly true.

At the same time, while we should all want management parameters to be calculated in a statistically rigorous manner, with a defensible point estimate, surrounded by a confidence interval, that can survive peer review, sometimes that’s just not possible.

And when you get right down to it, failing to create a buffer for management uncertainty—that is, proceeding as if the magnitude of such uncertainty is zero—is at least as arbitrary as creating a recreational harvest target that is ten or twenty percent below the recreational harvest limit.

Setting the level of management uncertainty isn't foregoing any action; it is affirmatively selecting zero as the most appropriate value.

And, arguably, setting the level of management uncertainty at zero, when the Monitoring Committee acknowledges that such uncertainty exists, if at a yet-unquantified level, is more arbitrary than establishing a buffer at some roughly estimated value, because the value of zero is known to be fals, while some other buffer might, at least, come somewhat closer to the real level of management uncertainty.

Right now, it is extremely likely that, because of management uncertainty, the current specifications will lead to higher than contemplated fishing mortality.  Just how much higher is anyone’s guess.

Fortunately, that situation may only last for a couple of years. 

A benchmark, or “research track,” bluefish stock assessment is scheduled for 2022.  Such assessment will allow scientists to consider new population models, or perhaps revise the one currently used.  It will also offer the opportunity for them to look into sources of uncertainty, including things such as the true level of recreational discard mortality, new ways to accurately survey older and larger fish, and perhaps even a way to survey the number of bluefish found farther offshore, and determine whether they are a part of a permanent offshore population, or merely transit between inshore and offshore waters over the course of the year.

Right now, it’s impossible to predict whether the new stock assessment will find bluefish to be in better or worse shape than currently believed.

Perhaps recreational discard mortality really is close to the GARFO assumption, and the stock is well on the road to recovery.  Perhaps it is closer to the Science Center calculation, and management measures must be made far more restrictive in response.  Perhaps, when all’s said and done, managers still won’t be sure of its magnitude.

In the same way, new surveys may show that there are plenty of bluefish offshore, and that the stock is not overfished.  They may also show that the number of bluefish age 6 and older is far less than previously thought, and that the stock is in real peril.

Again, we won’t know until the assessment is done.  And it’s possible that we won’t even know then, because given the amount of uncertainty biologists are dealing with, it’s always possible, if unlikely, that the new assessment won’t pass peer review.

So where do we, and the bluefish, go from here?

In the short term, into a rebuilding program that may, or may not, rebuild the stock within seven years.  It’s success will depend, in part, on the bluefish—will recruitment, for example, be robust enough to support rebuilding—and in part on the Council and Management Board, which must make hard decisions needed to rebuild the stock, and not the easy ones that might maximize landings for a short while, but lead to decreased future abundance.

Right now, there are reasons to be optimistic, and reasons to be concerned.

And most of all, there are reasons to keep watching the process, to make sure that no one allows itn to go astray.

 

 

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