SOME FAIRLY GOOD NEWS ON THE FLUKE FRONT

Sometimes, it’s nice to be wrong.

Based on a stock assessment update released a few years ago, years of poor recruitment, and reduced landings along the coast, I was expecting the 2018 benchmark summer flounder stock assessment to bring mostly bad news. 

But once again, I was reminded that it’s best to leave fisheries science to the people who have trained all their lives to do that sort of work, and merely report on their findings, because the news conveyed by the benchmark assessment was, on the whole, pretty good.

It’s not official yet—the recent government shutdown delayed the release of the final version—but we already know that the 2018 assessment has passed peer review, and will guide future management decisions.  But the new benchmark assessment clearly states that

“The final model adopted by the 2018 [Stock Assessment Workshop] 66 [Summer Flounder Working Group] for the evaluation of stock status indicates that the summer flounder stock was not overfished and overfishing was not occurring in 2017 relative to the biological reference points established in this 2018 SAW 66 assessment.  [emphasis added]”

Even better,

‘[Spawning stock biomass] was estimated to be 44,552 [metric tons] in 2017, 78% of the new biomass target reference point,”

which is a substantial improvement over the estimated 58% of biomass target included in the Scientific and Statistical Committee’s report to the Mid-Atlantic Fishery Management Council prior to its August 2016 meeting.

As a result of that improvement, summer flounder catch limits will almost certainly increase substantially over those tentatively set at the August 2018 Mid-Atlantic Council meeting.

A memo from Mid-Atlantic Council staff, that will be reviewed at the February 21 meeting of the Council’s Scientific and Statistical Committee, recommends increasing the 2019 commercial fluke quota from 6.67 million pounds to 10.82, and increasing the recreational harvest limit from 5.15 to 7.21 million pounds.

That’s a large increase, and unless something very unexpected happens, we can expect to see recreational summer flounder regulations significantly relaxed this year.

How and why that’s happening demonstrates the way that good data drives good fisheries management, and how all fishermen can benefit from a science-driven management process.

When a benchmark assessment is performed, the stock assessment team starts at the very beginning, asking whether the assessment approach they had used before is really the right one, or whether a completely new model is needed.  In the case of the 2018 benchmark assessment, biologists considered a number of different assessment models; they settled on a model that was similar to the one used five years before, but contained many revisions that were expected to improve the accuracy of its results.

The assessment team considered, but ultimately rejected, a new model that included much more sex-specific data than had been included before, an approach that has been pushed by some members of the angling community over the past few years.  Contrary to the claims of a segment of the recreational sector, biologists on the Summer Flounder Working Group determined that

“There were not strong differences in model outputs (i.e. trends in [spawning stock biomass], [fishing mortality], [recruitment]) between those models that incorporated additional sex-specific complexity and those that did not; therefore, gains from the additional sex-specific information were not shown, and did not warrant selection of a less-developed model that required additional parameters and assumptions.”

However, that doesn’t mean that such a sex-specific model won’t be adopted at some point in the future.  One member of the peer-review panel endorsed the 2018 assessment, but also advised that

“differences in growth by sex of summer flounder complicates the derivation of appropriate management reference points.  It would therefore be useful to continue to develop and implement an appropriate separate-sex assessment model.”

Perhaps in another five years, that will happen.  Or, perhaps, it will not.

In any event, even though the model used in the 2018 benchmark assessment wasn’t radically different from the model used in 2013, it did use different inputs, and generated different results.

For anglers, one of the most-watched issues was how the new estimates of recreational catch and effort would impact the assessment.  Some in the angling community, who never took the time to become thoroughly familiar with the issue, were issuing alarms, claiming that higher estimates of recreational harvest would result in regulations so strict that people might not be able to fish at all.  But such a simplistic, if intuitive, view doesn’t reflect the way population estimates work.

In fact, according to the benchmark assessment,

“the ‘New’ MRIP recreational fishery catch estimates result in an increase of about 40% in stock size.”

So it looks like there are more fluke in the ocean than biologists previously thought.  Of course, that doesn’t necessarily mean that anglers will be able to take home more fish—the biomass target and threshold, for example, might have been pushed upwards, too—but in the case of summer flounder, that didn’t happen.

As I mentioned earlier, when biologists prepare a benchmark assessment, they more-or-less start from scratch, looking at all of the data that has been compiled, including data relating to the ratio of males to females, the size of fish at any given age, and the size and age of fish when they mature.  It turns out that all of those things have changed in the years since the 2013 benchmark assessment was prepared. 

The assessment noted that

“The [Northeast Fisheries Science Center] survey data show trends in the most recent years of decreasing mean length and weight at age in all seasons and for both sexes…that indicates ‘slower growth…, and a trend of delayed maturity…There are trends in sex ratio that indicate a decreasing proportion of females (and therefore an increasing proportion of males) for ages 2 and older.  These trends in life-history characteristics had an important effect on the values of the biological reference points updated in the assessment.  [emphasis added]”

As a result of those changes, the stock assessment advises, the target biomass should be reduced slightly, from 62,392 metric tons to 57,159 metric tons; at the same time, the threshold fishing mortality rate, which is defined at the fishing mortality rate that would maintain the spawning potential of the stock at 35% of the potential of an unfished stock increased from 0.309 to 0.488.

It might seem counterintuitive to increase the fishing mortality rate while reducing the spawning stock biomass target, but the benchmark assessment explains

“The increase in the [fishing mortality] reference point (and [maximum sustainable yield]) but decrease in the biomass reference point is due primarily to the effect of decreased mean weight at age for older ages (mainly ages 6 and 7+, because of increasing numbers of older fish available in fishery and survey samples and increasing numbers of males [which are smaller and of lower mean weight] present in the catch and survey samples at those ages)…”

Because of that, we should be able to put a few more fluke in the cooler this year.

But it’s not all good news.

Recruitment of new fish into the population remains at below-average levels.  A stock assessment summary provided to the Mid-Atlantic Council’s Scientific and Statistical Committee warned that

“The assessment shows that current mortality from all sources is greater than recent recruitment inputs to the stock, which has resulted in a declining stock trend.”

So if recruitment doesn’t get better, the good news is going to come to a screaming halt.

There’s also another, subtle threat that hovers over my home state of New York.

We had an awful fluke season in 2018.  There was some decent action in a few places, largely off Long Island’s East End, and there were some very large fish in the mix.  But over all, last year, New York anglers harvested about 560,000 summer flounder.  That’s less than half of the nearly 1.2 million fluke that they landed in 2017, even though the 2018 bag limit was a little larger, and the 2018 season a little longer, than in the previous year.

It’s not completely clear why landing were so low.  A coastwide lack of fish probably wasn’t the case, because landings didn’t drop as sharply anywhere else on the coast.  Thus, there is a reasonable chance that New York’s landings might have bounced back on their own in 2019, even without any change in regulations.

And therein lies a trap.

The Mid-Atlantic Council had already planned to increase summer flounder landings by 16% in 2019, to 5.15 million pounds; based on the staff memo mentioned above, that 5.15 million pound figure will be increased by another 28%.  Combined, that’s a substantial year-to-year increase that should keep most anglers happy.

But because each season’s regulations are usually crafted by looking back at what anglers landed under the previous year’s rules, there is a chance that some in New York will demand an even larger increase in harvest, one based on what anglers actually caught in 2018, and not on the state’s recreational quota. 

Doing that could create a real problem if whatever conditions led to the state’s unusually low landings last season do not recur in 2019, leading landings to double even before any increase attributable to the new, higher harvest limit kicked in, and causing New York anglers to blow right through their share of the recreational quota.

We should hope that New York regulations keep that risk in mind.

So yes, there are a couple of things that we need to keep our eye on. 

But those things shouldn’t distract us from the main message of the stock assessment.

Anglers should be looking forward to eating more fluke, without risk to the stock, in 2019.