SOME REAL WORK WILL BE NEEDED TO REBUILD STRIPED BASS

 

On June 5, 2023, the Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Plan Development Team and Atlantic Striped Bass Technical Committee discussed the next steps in rebuilding the striped bass spawning stock.

The stock is currently overfished, but slowly recovering.  Unfortunately, poor recruitment of young fish into the striped bass population is hampering rebuilding efforts; the Technical Committee’s most recent projections show that, beginning around 2027 such low recruitment will cause the spawning stock to begin a gradual decline, unless fishing mortality is reduced enough offset the lack of recruits.

Thus, the June 5 meeting focused on the level of harvest reductions that might have been achieved by recent management actions, as well as the additional reductions that will be needed to rebuild the stock by 2029, the deadline mandated in the ASMFC’s striped bass management plan.  It was a three-step process, in which the Technical Committee first estimated the effects of the Atlantic Striped Bass Management Board’s recent emergency action, which established a 31-inch maximum size for all recreationally-caught striped bass, then considered the sort of management measures that might be included in the draft Addendum II to Amendment 7 to the Interstate Fishery Management Plan for Atlantic Striped Bass, which will be presented to the Management Board at its August meeting, and finally discussed, in very general terms, what might have to be done to rebuild the spawning stock by the 2029 deadline.

By the time the meeting had ended, no concrete management measures had been proposed, although both the PDT and the Technical Committee had a good idea of how the emergency measures would impact 2023 striped bass fishing mortality, and how Addendum II would likely affect striped bass rebuilding. 

Sitting on the sidelines, listening to the various scientists discuss the issues, it was clear that while rebuilding the spawning stock is possible, every sector of the fishery is going to have to invest a lot of work, and a lot of shared pain, to get the job done.

As we all should have known from the beginning, the emergency measures, even if adopted on a permanent basis, won’t be enough to rebuild the stock.  They were never intended to do so.  The Management Board’s adoption of the emergency measures can best be likened to someone grabbing an old, grimy rag and using it to put pressure on, and staunch the bleeding from, a gaping arterial wound.  It’s not a perfect solution, there might be some leakage, and the risk of infection is high.  But the first priority is to stop the bleeding, regardless of how, or else the patient is going to die, making those other concerns more or less irrelevant.

The emergency measures were only intended to stop the bleeding--the increasing recreational landings--until something more permanent could be contrived.  Even so, the Technical Committee estimated that the emergency measures will reduce recreational striped bass fishing mortality by about 29 percent, compared to 2022. 

That estimate includes substantial uncertainty when it comes to how recreational release mortality will be affected by the emergency measure.  

Under the former 28- to 35-inch slot limit, some anglers might have released sub-31-inch fish, hoping to catch and retain a somewhat larger bass; if that was the case, by removing the option of keeping a larger fish, the emergency measure might conceivably reduce the number of fish released, and so slightly reduce fishing mortality.  On the other hand, striped bass don’t bite in any sort of size order, with smaller fish taking the hook before large ones.  To the extent that an angler who might have had the opportunity to retain a larger, 31- to 35-inch bass can no longer do so, it is possible that such angler will release a substantial number of large fish before finding one that fits within the emergency slot, in which case release mortality could increase somewhat.

And then there are the more extreme situations.  It is possible that the narrow, emergency slot might make landing a legal fish difficult enough that some anglers will no longer consider striped bass fishing worthwhile; in such cases, both landings and release mortality would decline.  But there are also anglers who rarely if ever take home a striped bass; the emergency slot would have no impact on them at all, and the fishing mortality attributable to them would remain exactly the same.

A final consideration is that, outside of the very slightly above-average 2017 and 2018 year classes, the year classes produced after 2015 have all been very small, which means that, with most of the 2015 year class now falling within the slot, anglers will catch far fewer undersized bass, resulting in less release mortality, simply because there will be fewer small bass in the water for anglers to catch.

In their efforts to estimate 2023 release mortality, Technical Committee members need to take all of the foregoing scenarios into consideration, and try to predict which ones will prevail.  History, and particularly the history of the 2011 year class, can provide substantial guidance but, in the end, a lot of uncertainty remains.

Taking all things into account, the Technical Committee projected that the emergency measures would reduce 2023 removals by a little less than 4.9 million fish, which falls short of the 5.7 million fish reduction needed to lower fishing mortality to the target fishing mortality rate.

Even if the target fishing mortality rate was achieved, rebuilding would remain unlikely.  The Technical Committee projected that reducing the fishing mortality rate to 0.17 would still only provide a 28 percent probability of rebuilding by 2029.

Having said that, the wording of the motion made at the May 2^nd Management Board meeting, which initiated the work on Addendum II, made rebuilding more difficult, as it reads in relevant part

“Move to initiate an Addendum to implement commercial and recreational measures for the ocean and Chesapeake Bay fisheries in 2024 that in aggregate are projected to achieve F-target from the 2022 stock assessment update (F=0.17)…”

Such unfortunate wording limits Addendum II management actions to those which achieve the target fishing mortality rate, and does not contemplate reducing fishing mortality to the rate needed to rebuild the stock by the 2029 deadline.  That issue was recognized at the June 5 meeting, when those present acknowledged that, following the 2024 stock assessment update, it will probably be necessary to take yet another management action that goes beyond Addendum II, and finally adopts the measures needed to rebuild the stock in a timely fashion.

Of course, the time lag between the release of the 2022 assessment update, the emergency action, Addendum II and, ultimately, the final rebuilding plan will mean that each management action is going to be more restrictive than the rebuilding measures would have been, had the Management Board initiated a rebuilding plan in 2019, as part of Addendum VI to Amendment 6 to theAtlantic Striped Bass Interstate Fishery Management Plan, instead of waiting until last fall to take its first serious look at the rebuilding process.

But dwelling on the past, and lamenting over missed opportunities, isn’t going to get the striped bass stock rebuilt. 

What will it take to get that done?

We don’t really know yet, as the Technical Committee hasn’t had a chance to crunch all of the numbers.    

To achieve the goal of Addendum II, reducing the fishing mortality rate to 0.17, probably won’t be too difficult.  It’s possible that moving the slot around a little bit, from 28 to 31 inches to some other bracket, might do it, but my guess—and it’s only a guess—is that just adjusting the recreational slot limit won’t be good enough.  Something more will be required. 

That something will probably include a cap on the size of fish caught in the commercial fishery, which may in turn require revisiting state quotas, to assure that catching the same poundage of smaller fish—meaning that more fish will be killed—won’t impair the spawning potential of the stock.  I strongly suspect that it will also include some sort of recreational season when striped bass harvest is not allowed.

To actually rebuild the stock, and not merely reduce fishing mortality to the target, will require further reductions.  At that point, I suspect—but, of course, can't know until the Technical Committee works out the numbers after the 2024 stock assessment update—that significant no-harvest recreational seasons and reduced commercial quotas will have to be considered.

Until we learn what the rebuilding plan will look like, we can take solace in the fact that managers at the ASMFC seem to be willing to adapt management measures to meet the stock’s needs.  Not long ago, they would set management measures after each benchmark stock assessment, then take no further action until the next benchmark assessment came around.  The days of such inaction appear to be over, for as one influential Technical Committee member, Dr. Katie Drew, noted at last Monday’s meeting, the folks at the ASMFC have learned that a “set it and forget it” approach to management measures just doesn’t work.

So long as managers retain that willingness to adjust management measures to the needs of the stock, as soon as such needs become manifest, and so long as fishermen are willing to make the sacrifices needed to rebuild the spawning stock and maintain it at a sustainable level, there is reason to hope--there is even reason to believe--that the striped bass population will, in fact, be rebuilt before the next decade dawns.