CONSERVING STRIPED BASS: DON'T BE MISLED BY MENHADEN

 

I’m probably going to upset some folks, but let’s get two things straight from the start: Striped bass are having some serious problems, while Atlantic menhaden are doing just fine.

I know that’s not the narrative that you hear from some quarters, so let’s do what we always should do when discussing fisheries issues—fall back on the science.  

With regard to striped bass, the last stock assessment update shows that the stock is overfished, although overfishing is no longer occurring.  Most of the striped bass on the coast are spawned in the Chesapeake Bay, with about two-thirds of the Chesapeake spawn occurring in Maryland, and the rest in Virginia.  Maryland has experienced spawning failure for the past five years.  Virginia for the past three.  And if the 2023 juvenile abundance index for the Delaware River proves to be as low as it was in 2021 and 2022, we’ll see spawning failure in that waterway as well.

So there’s no question at all that the bass stock is troubled.

When it comes to Atlantic menhaden, we see a very different outlook.  The Atlantic States Marine Fisheries Commission, which is responsible for managing the menhaden fishery between Maine and southeastern Florida, informs us that

“The [ecological reference point] assessment evaluates the health of the stock in an ecosystem context, and indicates that the fishing mortality (F) reference points for menhaden should be lower [than those used in a single-species stock assessment] to account for menhaden’s role as a forage fish.  The [ecological reference point] assessment uses…an ecosystem model that focuses on four key predator species (striped bass, bluefish, weakfish, and spiny dogfish) and three key prey species (Atlantic menhaden, Atlantic herring, and bay anchovy).  These species were chosen because diet data indicates that they are top predators of Atlantic menhaden or are key alternate prey species for those predators…

“In August 2020, the [Atlantic Menhaden Management] Board approved the following [ecological reference points] in the management of Atlantic menhaden:

“ERP target:  the maximum fishing mortality rate (F) on Atlantic menhaden that sustains Atlantic striped bass at their biomass target when striped bass are fished that their F target.

“ERP threshold:  the maximum F on Atlantic menhaden that keeps Atlantic striped bass at their biomass threshold when striped bass are fished at their F target.

“ERP fecundity target and threshold:  the long-term equilibrium fecundity that results when the population is fished at the ERP F target and threshold, respectively.

“Atlantic striped bass were the focal species for the [ecological reference point] definitions because it was the most sensitive predator fish species to Atlantic menhaden harvest in the model, so an [ecological reference point] target and threshold that sustained striped bass would likely provide sufficient forage for other predators under current ecosystem conditions…

“Under the [ecological reference points], Atlantic menhaden are neither overfished nor experiencing overfishing.  In 2021, population fecundity (FEC), a measure of reproductive capacity of the population, was above the ERP threshold and target…and fishing mortality (F) was below the ERP overfishing threshold and target…  [emphasis added]” 

In other words, the Atlantic menhaden stock is perfectly healthy.  Not only are there enough menhaden around to ensure the long-term health of the stock, provided that environmental conditions don’t change and fishing mortality doesn’t increase substantially but, because of how the ecological reference points are defined, there are more than enough menhaden in our coastal sea to support a completely recovered striped bass population—and our current striped bass population is still a very long way from that point.

So it’s completely clear, from a scientific perspective, that the current lack of striped bass has absolutely nothing to do with a lack of menhaden. 

That’s a fact that many people still don’t understand, and that lack of understanding creates a potential roadblock to effective striped bass management.

On October 18, I listened in on the most recent meeting of the ASMFC’s Atlantic Striped Bass Management Board.  At the beginning of the meeting, the Board’s Chair opened up the meeting to ten minutes of public comment, which was supposed to address issues that were not on the meeting agenda.  It seemed that most of the public wanted to talk about menhaden, and some of that talk made it clear why focusing too much on menhaden can harm the striped bass.

One speaker, Ron Zalesak, is apparently the president of the Southern Maryland Recreational Fishing Organization, which recently sued the state of Virginia over its commercial menhaden regulations (although it should be noted that Mr. Zalesak spoke only for himself, and did not hold himself out as a representative of the organization).  He argued that the mortality rate (he did not specify whether he meant the fishing mortality rate or the natural mortality rate, although the latter would seem more likely, given the context) of striped bass was “directly tied” to the mortality rate of menhaden, an assertion that does not find support in the latest benchmark stock assessment (it is possible that Mr. Zalesak was confused by the definitions of the ERP target and threshold, which are expressed in terms of a fishing mortality rate that leaves enough menhaden in the water to provide adequate forage for the striped bass stock; however, nothing in those definitions suggests that changes in menhaden mortality would necessarily lead to a change in striped bass mortality, as would be the case if the two mortality rates were “directly tied").

But where Mr. Zalesak’s comments really went astray was when he noted that Maryland’s striped bass harvest had decreased by 72% since 2016, then alleged that such decrease was due to a lack of menhaden, and not overfishing.  That comment, more than any other that he made, exposed the danger of focusing on menhaden, rather than on striped bass biology, for if managers took that allegation at face value, it would mean that to rebuild the striped bass stock, their first concern should be rebuilding the menhaden stock, and not addressing striped bass fishing mortality.  Such course could only lead to more problems for the bass population. 

After all, the benchmark stock assessment demonstrated that the stock was experiencing overfishing in 2016, and in the years immediately before and after,  Such overfishing could only drive down striped bass abundance in the long term.  Thus, managers’ first obligation—pursuant to the management plan as well as pursuant to the best available science—was to end overfishing and reduce fishing mortality to a sustainable level, something that was at least temporarily achieved in 2020 after Addendum VI to Amendment 6 to the Atlantic Striped Bass Interstate Fishery Management Plan went into effect.

If the Management Board had shared Mr. Zalesak’s beliefs, and focused on menhaden rather than on ending overfishing, the striped bass stock would almost certainly be in even worse condition than it is today.

Furthermore, Mr. Zalesak’s comments also ignored the impact of spawning success on striped bass abundance, and on the striped bass catch in the Chesapeake Bay. 

 In 2016, Maryland striped bass anglers were still enjoying the benefits of the big 2011 year class of striped bass, the fourth-largest year class recorded in the Maryland juvenile abundance survey, which dates back to the 1950s.  Another big year class, the 2015s, were still too small to harvest, but were nonetheless being caught by anglers.  With the exception of 2017 and 2018 year classes, which were marginally above-average, striped bass spawning success for the rest of the relevant period was far below average, with spawning failure occurring in the last five years.  Given that so many fewer fish were available to anglers in recent years, it’s hardly surprising that Maryland’s recreational striped bass catch fell by roughly 73.5% between 2016 and 2022, from about 15.3 million fish to less than 4.1 million, and harvest, which is less dependent on the most recent year classes fell by about 58.5% during the same period.

The decline Mr. Zalesak referred to was solely due to factors affecting the abundance of striped bass—overfishing and poor recruitment—and not the abundance of menhaden. 

The most recent benchmark stock assessment noted that the model used to develop the ecological reference points

“predicted that Atlantic Menhaden comprised a moderate proportion of striped bass diet biomass (15-30%) and those consumed consisted largely of age-0 and age-1 Atlantic Menhaden,”

although it also noted that

“diet studies of large striped bass by Walter and Austin (2003) and Overton et al (2008) suggested a greater role of Atlantic Menhaden of all ages in striped bass diets.”

Maryland found that the abundance of juvenile menhaden in 2023 was the highest that it has been since 1990; the big striped bass year classes of 1993, 1996, 2001, 2003, 2011, and 2015 were supported by far smaller juvenile menhaden populations than we see today, which ranged between 10.1% and 24.1% of current juvenile menhaden abundance (the 1996 year class, the largest in the time series, occurred when Maryland’s juvenile menhaden abundance was 14% of what it is in 2023), which again provides compelling evidence that a lack of menhaden has little to do with the current state of the striped bass population.

Yet we constantly hear menhaden blamed for the lack of striped bass, and not only by Maryland anglers.  Two Connecticut charter boat captains who also commented at the October 18 meeting seemed to blame menhaden for the lack of striped bass activity.  One said that he was not seeing menhaden, but that there was nonetheless

“An abundance of striped bass about two miles outside the harbor,”

while the other argued that the amount of larger striped bass—defined as fish over 25 pounds—was “100% related” to the amount of menhaden in the area.  He connected the lack of striped bass in his area to the recently increased commercial menhaden quota, saying’

“I have not seen a pod of bunker in months now, months.”

What he apparently also did not see—or did not care to look at—was the Maryland juvenile abundance index from a few years ago.  For if we assume that a 25-pound striped bass is 12 or 13 years old, and we look at striped bass recruitment from, say, 12 to 20 years ago, we find decent year classes in 2003 (fish that would be close to 50 pounds today) and 2011 (bass just approaching, or just above, the 25 pound mark), but in between those years, the Maryland juvenile abundance index, which provides the best single gauge of striped bass abundance, was well below average.  (It should be noted that the Hudson River produced a large year class in 2007, which contributed to the number of 40-pound fish available today, particularly in areas such as Raritan Bay, New York Harbor, western Long Island Sound and off Long Island’s western South Shore.)

It might be somewhat reassuring to blame a lack of larger bass on a lack of menhaden, particularly if you’re a charter boat captain who doesn’t want to see more restrictive regulations that might chase away customers, but the plain truth of the matter is that you can’t catch a fish that was never spawned, and relatively few bass were spawned during the years 2004-2010, leaving a big hole in the population structure.

Menhaden might make the relatively small number of larger bass easier to catch, but the lack of larger striped bass on many parts of the coast is, again, primarily due to poor recruitment in the Chesapeake Bay, and not a lack of menhaden.

So why are so many people focused on menhaden as the primary cause of the striped bass’ problems?  Probably because the fish was, at one time, the worst-managed fish out of all the species under the ASMFC’s aegis, with the menhaden industry, and particularly the menhaden reduction industry, setting the rules and providing the supposed science in a classic case of the fox guarding the henhouse.

That led to a lot of pro-menhaden publicity, as a number of conservation and recreational fishing organizations fought, for many years, to oust the industry from its catbird seat and create the same sort of management structure for menhaden as the ASMFC used for every other stock it manages (I began working on menhaden issues around 1996 or 1997, and know folks who already had years invested in the issue before I ever came on the scene).  That issue was finally resolved in 2001.

Then, in 2007, H. Bruce Franklin wrote a book titled The Most Important Fish in the Sea, which arguably overstated menhaden’s importance (are they really more important, all things considered, than mullet, herring, sardines, or sand eels?) and contained some misinformation (adult menhaden’s characteristic filter feeding is probably not critical to the health of East Coast bays), but undoubtedly thrust the menhaden into the public consciousness, with not only anglers, but birdwatchers, marine mammal fans, and others concerned with the health of the nation’s coastal waters becoming overnight menhaden advocates.  Conservation groups benefitted from the increased public awareness, and menhaden remained high on their priority lists.

That translated into undoubtedly worthwhile efforts to have menhaden managed primarily for their value as forage fish, rather than as a commodity reduced into fish oils and meal, and various industrial feedstocks, which culminated in 2017’s Amendment 3 to the Interstate Fishery Management Plan for Atlantic Menhaden, which opened the door to ecological reference points, and ultimately in the 2019 Atlantic Menhaden Ecological Reference Point Stock Assessment Report which, for the first time, applied ecological reference points to the menhaden stock, and found that even under that more restrictive standard, the stock was unquestionably in good health.

By any rational measure, the menhaden advocates had won.  They could point to a healthy menhaden stock capable of fulfilling its role in coastal ecosystems, a sustainable menhaden harvest and, for the first time at the ASMFC or, for that matter, in any East Coast fishery, a management plan based on the ecological role of the managed species, and not merely on sustainable landings.

There are still some peripheral issues outstanding, such as the possibility of local depletion, particularly in the Chesapeake Bay; of damage to inshore bottom structure when nets were deployed in shallow water, and the level of bycatch in the menhaden fishery.  All are worthy of further discussions.  But, when viewed from a stock-wide perspective, the menhaden advocates had achieved all of their major goals.

But then, a funny thing happened.  Many of the advocates did not understand that they’d won.  Instead, they started to blame largely imagined problems in the menhaden stock for real issues in other fisheries.

Right now, on the Atlantic coast, striped bass are the biggest victim of that misunderstanding, as well-meaning advocates—and others seeking to find a justification for continued overharvest—blame the decline in striped bass abundance on a supposed lack of menhaden.

That can have very real, and very negative, consequences for the striped bass stock, if managers fail to take meaningful measures to reduce striped bass fishing mortality, and abandon meaningful efforts to timely rebuild the striped bass population, and instead focus on the menhaden fishery as the cause of the striped bass decline.

Now that the ASMFC’s Atlantic Striped Bass Management Board has approved Addendum II to Amendment 7 of the Atlantic Striped Bass Interstate Fishery Management Plan for public comment, and will be holding hearings all along the striper coast during November, everyone concerned with the health of the striped bass stock must focus on the real problems confronting the bass, and not cloud the issue with unsupported allegations of a menhaden shortage.

For make no mistake:  There are people who are all too willing to stall the striped bass’ recovery, and to put the bass’ future in peril, in order to increase their short-term gains from the fishery.  Some of those people even hold seats on the Management Board.  Handing them a ready-made excuse to stall, or at least weaken, Addendum II, and blame the bass’ problem on menhaden, is the last thing that the striped bass, or striped bass fishermen, need at this time.

As the hearings on Addendum II begin, the Management Board must hear our desire to reduce striped bass fishing mortality.  It must hear that we want the Board to act quickly in response to an adverse stock assessment in 2024.  It must hear of our concerns with spawning failure in the Chesapeake Bay.  For all of those things bear on the future health of the striped bass stock.

But the Board shouldn’t have to hear about menhaden at all.