THE SAME OLD BULL***T ABOUT STRIPED BASS

 

It doesn’t really matter what the fishery is.

Start talking about imposing new regulations to rebuild a stock, or even to halt a stock's decline, and the first thing you know, somebody starts hopping up and down, eager to tell you why the new rules won’t work, why they’re not needed, and/or why the science is out of whack, and how the fish stock in question isn’t just healthy, but it’s so healthy that, for the sake of the ocean, we ought to be killing quite a few more.

If you’re a striped bass fisherman, and if you’ve attended some fisheries meetings, you know the sort of thing that I’m talking about.  

In the face of a stock assessment finding that the stock is both overfished and experiencing overfishing, we saw one set of folks who tried very hard to convince us that the bass stock was still healthy, but the fish had just moved far offshore, a position that immediately falls apart when you stop to realize that bass are an anadromous species that spawn well up coastal rivers, and thus would be picked up by state surveys during the spawning period if such a pool of offshore fish really existed (yes, bass sometimes venture offshore, following or looking for schools of baitfish, but research conducted in Massachusetts demonstrated that they all return inshore pretty quickly).

Then there’s the old “there’s so many striped bass that they’re eating everything else in the water” claim.  I mentioned one example of that in last Sunday’s post; another very typical comment came from Russell Dize, Maryland’s Governor’s Appointee to the Atlantic States Marine Fisheries Commission and its Atlantic Striped Bass Management Board.  At the October 2014 Management Board meeting, in response to efforts to reverse a decline in the spawning stock biomass by reducing fishing mortality by 25%, Mr. Dize said,

“I’ve been a commercial fisherman for 55 years in Maryland.  I’ve watched the striped bass come and go.  At this time, we’ve probably got more striped bass in the bay than I’ve ever seen in my life.  We’ve got so many striped bass that it’s affecting our crab-catching industry.  We are probably down to a low ebb last summer on crabs.

“One of the predators is rockfish, striped bass.  When the charterboats catch the striped bass and they clean them, you can count anywhere from ten to forty small crabs in the belly of a rockfish…”

Thus Mr. Dize checked two of the boxes; despite a peer-reviewed stock assessment that found the spawning stock biomass to be in decline, he was claiming that Chesapeake Bay held “more striped bass than [he’s] ever seen in [his] life.”  And, of course, those super-abundant striped bass were eating all the crabs, and thus should not receive more protection.

We always hear that sort of thing, and it’s pretty much expected.

But ever since the 2018 benchmark stock assessment came out, setting a higher biomass target than any previous assessment, we’re also hearing people start to wonder out loud whether such target was attainable.  The first such source of dissent was probably Maryland fishery manager Michael Luisi, who commented at the April 2019 Management Board meeting that

“currently the threshold reference point is 91,000 metric tons and 125 percent of that puts us at a target value, and when you look at the estimate of spawning stock biomass that came out of the benchmark.  We have never achieved the target in all of that time as we’re evaluating that.”

Mr. Luisi can be excused his comment, for he thought it was true at the time, even though the 2022 stock assessment update revealed that, despite an excessive fishing mortality rate, female spawning stock biomass actually did rise above target for four consecutive years, 2002-2005 and, again despite above-target fishing mortality, managed to fall just short of the target during the years 2008-2010.

It’s much more difficult to excuse those who, despite the information provided in the 2022 assessment update, are still trying to argue that the current biomass target isn’t realistic, justifying their positions by saying things like “it has only been attained” two (or three, or four) times “in the past 40 years.”  

While it would be easy to overlook such comments, and write them off to ignorance, some are being made by folks who are not ignorant at all, but are very familiar with the data and the fishery management process. 

Given where some such comments are coming from, there is very real risk that many anglers will begin to believe them, and start undercutting the ASMFC’s efforts—and the ASMFC’s obligation—to rebuild the stock by 2029.

So to see where such comments go wrong, let’s take a look at them from a few different angles.

The right place to start is probably in the past.

When people say things like “Spawning stock biomass only reached target two [or three, or four] times in the past 40 years, we’re talking about the period 1983-2022.  The striped bass stock collapsed in the late 1970s, and remained in a collapsed state throughout the 1980s, with female spawning stock biomass bottoming out in 1987.  So for the first seven years of that 40-year period, managers were trying to figure out how to deal with—and recover—a collapsed striped bass stock.

To argue that we can’t achieve the target biomass today, because we didn’t achieve it during a period when the stock had actually collapsed, is really no argument at all.

Taking the 1980s out of the picture, because of the stock collapse, cuts the relevant time period down to 33 years.  But even considering that shortened length of time, the arguments against the current biomass target necessarily fail.

After all, once a stock collapses, it has a long, long way to go to get back to its target level.  The 1990s were a time of rebuilding, with the first six years, from 1990 through 1995, seeing the spawning stock biomass raised to the threshold level; at that point striped bass were no longer overfished. 

Of course, rebuilding was only partway done at that point; the stock was still waxing toward its target level.  Thus, it’s not reasonable to consider those six years when trying to decide whether the target is reasonably achievable, for rebuilding was still underway.

That contracts the rebuilding skeptics' 40-year reference period even more, down to just 27 years.  And even then, striped bass abundance, measured in female spawning stock biomass, was still on an upward trend. 

It wasn’t the sharp upward trend demonstrated between 1988 or so and 1995; striped bass recruitment varies a lot from year to year, depending on environmental conditions on the spawning grounds, so after ’96, there was some retrenchment.  But a full rebuilding was achieved by 2002, despite the recreational regulations that prevailed at the time, which allowed anglers on the coast to keep two striped bass at least 28 inches long.  

And despite such rules, which allowed fishing mortality to creep above its target rate, spawning stock biomass remained above target through 2005.  The fact that the stock began experiencing overfishing in 2004, and that such overfishing became more severe through 2007, then forced spawning stock biomass below the target once again.

During the period 2004-2017, the striped bass stock suffered overfishing in all but three years, and in one of those years, the fishing mortality rate was just about equal to the overfishing threshold.  Under such conditions, it’s not reasonable to expect the stock to achieve target biomass.  

It’s far more reasonable to expect the stock to become overfished which, in the real world, is exactly what happened.

History thus teaches that attaining target biomass is not an impossible dream.  To do it, we only need to keep the fishing mortality rate at or below the fishing mortality target.  It’s not all that difficult to do so, although it will require a more dynamic sort of fisheries management than we normally see at the ASMFC.

Typically, the ASMFC has engaged in what might best be described as “plug-and-play” fisheries management.  It waits until a benchmark stock assessment is produced, which usually happens about every five years.  If the fishing mortality rate is too high (historically, the Management Board has been very slow to act if biomass has fallen too low), the Management Board then adopts measures intended to reduce the fishing mortality rate back to its target level.  Such regulations then remain in place until the next benchmark stock assessment, regardless of how the fishery might perform in the meantime.

Such an approach to striped bass management allows the stock to deteriorate for years before any action is taken to correct the problem; over the past decade, it has allowed the stock to become overfished because the Management Board has failed to intervene when the first signs of excessive fishing mortality appeared.

The Management Board has always preferred to address an existing crisis, and has always seemed averse to early intervention, that might head off the crisis before it occurs.

Right now, we know—and, more importantly, the Management Board knows—that fishing mortality is well above the fishing mortality target, although the stock is not yet experiencing overfishing.  To rebuild the stock, the Management Board need only reduce the fishing mortality rate to its target level—or maybe a little below—to have a better than even chance of rebuilding by the 2029 deadline.

That can probably be accomplished merely by narrowing the slot size limit—now, 28 to 35 inches—to something like 28 to 30, or 28 to 32, or whatever other configuration that the Atlantic Striped Bass Technical Committee determines will get the job done.

And once the female spawning stock biomass is rebuilt to target, we can address the other flaw in the “four out of forty years” argument—the assumption that a stock must always remain at or above target to be considered healthy.

In fact, that doesn’t happen. 

While a rebuilding plan is intended to restore the spawning stock biomass to its target level, once that is accomplished, striped bass abundance will naturally fluctuate.  Should conditions favor strong recruitment, spawning stock biomass may well rise above the target, and stay there for a few years.  Should unfavorable conditions prevail, as they have for the past four years (and will probably be the case this year as well), abundance will drop below target for a few years, until spawning conditions improve.

Such fluctuations are contemplated in the ASMFC’s management plan.  A provision in Amendment 7 to the Interstate Fishery Management Plan for Atlantic Striped Bass states that

“If female [spawning stock biomass] falls below the target for two consecutive years and the [fishing mortality] rate exceeds the target in either of those years, the striped bass management program must be adjusted to rebuild the biomass to a level that is at or above the target within an established timeframe [not to exceed 10 years].  [emphasis added]”

In the end, the fishing mortality rate is the key to it all. 

Keep it at or below target, and biomass will eventually come close to, and sometimes exceed, its target as well.  If recruitment conditions are poor, spawning stock biomass may well remain below target for a while, but over the long term, so long as fishing mortality is adequately constrained, spawning stock biomass will, in time, reach the biomass target.

That’s what the “just four times in forty years” crowd forgets, or at least forgets to mention.  Constraining fishing mortality is a prerequisite to having abundant striped bass. 

In the 20 years [because, as we’ve illustrated, 40 years is a meaningless measure] since striped bass were fully restored in 2002, striped bass fishing mortality has only been below the fishing mortality threshold four times, in 2006, 2008, 2020, and 2021; for the rest of that time, overfishing has occurred.  Given that, it is hardly surprising that abundance has waned.

But keep fishing mortality below the fishing mortality target—something we’ve successfully done as recently as two years ago—and rebuilding biomass back to its target level becomes a very achievable goal.