Sunday, July 16, 2023

WHISTLING PAST THE GRAVEYARD

 

Fisheries don’t collapse all at once. Instead, they telegraph their distress with signals that may be subtle at the start, but grow more insistent as stocks decline.

Often, at least in the case of migratory stocks, the first sign of trouble might be a contraction of the fish’s range. On the East Coast of the United States, most migratory inshore species have centers of seasonal abundance. There is a core summer range, where the fish feed and are most abundant after their northward migration, and there is typically a core winter range, where they escape the worst of the cold.

Striped bass provide a good example.

Although scattered fish may appear anywhere along the coast during the summer, the species’ core summer range extends from eastern Long Island to southern Cape Cod, and includes both Block Island and the Elizabeth Islands off Massachusetts. Even when the striped bass population was at its lowest ebb during the early 1980s, fishermen could often find significant concentrations of fish, including some very large individuals, around Block Island, the outer Cape Cod beaches, and elsewhere in that core range, at a time when it was extremely difficult for anglers to locate even one bass anywhere else.

But when an increasing population creates more competitive pressure, fish begin to spread out from the core into the extremes of their range. Thus, Maine can see very good striped bass fishing when the stock is healthy but, because it is also the first state to feel the effects of a shrinking population, it is a bellwether for stock decline.

The November 2011 meeting of the Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Management Board (Bass Board) illustrated how that works. An update to the striped bass stock assessment had just been released. It advised that the population was declining, and would become overfished within six years.

Massachusetts biologist Gary Nelson, who was presenting the assessment update, explained, “The striped bass stock is contracting [its range] because of getting small, fish tend to do that. They like primary [range] and then if the population is too big, they start to expand [their range]. Maine is at the edge of the distribution. When the population is going down, you’re going to see fewer fish there simply because of that impact.”

Unfortunately, the Bass Board didn’t heed the warning signs, and the most recent benchmark stock assessment found that the stock had, in fact, become overfished by 2017.

A change in the size of fish caught, or the absence of large or small fish in a population, can also be a sign of future problems. It is well known that fishing can lead to truncation of the age and size structure of a fish population. Thus, when fishermen begin encountering fewer older and larger fish than they had before, it is a good indication that fishing mortality has increased, perhaps to unsustainable levels.

 

The health of a stock is also threatened when there are too few young fish entering the population to replace the older individuals removed by both fishing and natural mortality. A stock of fish composed mostly of larger individuals may entertain anglers for a brief time, but at the risk of eventual, and likely, collapse. Both the collapse of the Atlantic striped bass stock in the late 1970s and early 1980s, and the collapse of the southern New England/Mid-Atlantic stock of winter flounder twenty years later, were preceded by long periods of recruitment failure that created declining populations made up largely of older individuals.

 

As stocks enter deeper declines, fish become harder for fishermen to find, and scientific assessments eventually reveal that the stock is either overfished, experiencing overfishing or, as with the 2011 striped bass assessment, at least well on the way to crossing one or both of those thresholds.

Unfortunately, fishermen, whether recreational or commercial, rarely heed the first signs of trouble. Too often, particularly when short-term economic consequences might ensue, they tend to be like children whistling as they walk past a graveyard, trying to deny their fear of the ghosts and ghouls that might be residing therein; instead of recognizing and addressing impending threats to a stock, fishermen often aggressively deny that any such threats exist.

That can have dire consequences for the fisheries involved, for while ghosts and ghouls don’t really exist, threats to many heavily exploited fisheries are all too real, and they can cause very serious harm if ignored.

I was reminded of that once again when I attended the most recent meeting of New York’s Marine Resources Advisory Council (MRAC). One of the topics on the agenda was the emergency management action taken by the Bass Board at its May meeting, which set a maximum size of 31 inches for striped bass, effectively reducing the 28- to 35-inch slot limit in place along most of the coast to a narrow, 28- to 31-inch slot. Such action was taken to reduce recreational landings, which spiked in 2022, to more sustainable levels.

 

Recent data developed by fishery managers makes it clear that the striped bass stock is experiencing some serious problems. The stock, to the best of anyone’s knowledge, remains overfished, although the spawning stock has been expanding slowly, and it’s likely that spawning stock biomass will creep above the biomass threshold at some point this year.

But that will probably be only a temporary reprieve.

In Maryland’s portion of the Chesapeake Bay, which is the single most important striped bass spawning ground, the Maryland juvenile striped bass abundance index (JAI) is crashing. The average JAI for 2019 through 2022 is the lowest four-year average in the 65-year history of the Maryland survey; even during the early 1980s, when the striped bass stock had collapsed, no four-year period ever quite reached that nadir.

 

Cold winters and cool, wet springs are usually needed to produce strong year classes of striped bass. The winter of 2022-23 was unusually warm, and was followed by a warm spring that saw low water flows in the Chesapeake tributaries. Such conditions set the stage for what will probably be another very low JAI.

That’s going to leave a big hole in the striped bass age structure, with at least four, and probably five, year classes largely absent from the population. This year, one of the things that I’m noticing, and that I’m hearing from others, is that fish less than 24 inches or so in length have been scarce in most places this season.

That’s not a good sign.

Yet those who stand to be the most heavily impacted by the decline in striped bass abundance, commercial fishermen and owner/operators of for-hire vessels, seem to be trying very hard to convince themselves that the striped bass stock is not facing an imminent problem.

One MRAC member, who operates a charter boat on eastern Long Island, seemed almost stunned by the thought that striped bass abundance will, almost inevitably, decline. He kept talking about how many fish he was seeing now, noting that he was catching bass of all sizes “from about 24 inches up.” He effectively acknowledged that his customers weren’t catching striped bass any smaller than that, but couldn’t connect the current lack of small fish with a future decline in the spawning stock. Instead, he asked the rhetorical question, “Are you telling me that when the 2015s are gone, there won’t be any striped bass?” and then shook his head and declared “I don’t believe that.”

Another for-hire operator in the audience rose to say that one of his closest friends was a Maryland biologist who did striped bass work, and who supposedly told him that environmental conditions in the Maryland area were so bad that “we can forget about Chesapeake Bay.” He went on to assert that ocean conditions were changing, waters were getting warmer farther north, and somehow—he didn’t try to explain the mechanism involved—the bass will end up doing just fine, without the need for the emergency action, as other fish from other, unnamed places replaced those spawned in the Chesapeake Bay.

It was magical thinking at its best.

The only problem was that magic, like ghosts and ghouls, isn’t real, while spawning failure in Maryland’s waters is.

I eventually spoke, supporting the emergency measures, and spent a little time comparing the current Maryland spawning data with that which was developed 45 years ago, when fishery managers failed to respond to poor spawning success (the Bass Board had no legal authority to take binding action back then) and the bass stock quickly collapsed. I was only citing the JAI data and referencing historical facts, but out in the audience the head of one of New York’s largest party and charter boat organizations apparently didn’t want to hear it; he made a loud, exasperated noise, quickly stood up, and walked out of the room.

At that point, a commercial MRAC member tried to assure everyone that the problem was with the data, not the striped bass, questioning the accuracy of the Maryland JAI, the stock assessment, and the recreational landings data from 2022. To him, there was no such thing as good fisheries data; it was all nothing but guesses. He declared that the striped bass were doing fine, and no mere numbers were going to change his mind.

Other people took similar tacks, arguing that the 2022 recreational landings estimate was “just a single data point,” suggesting that the Marine Recreational Information Program data was wrong, and that emergency action could not be justified unless the validity of that data could be confirmed, perhaps by fishing for another year under the same 2022 rules. There was a certain irony in their words, as on one hand, they argued that no emergency action was needed, as they were catching more bass now than they had in years, and on the other hand, they argued that the data showing them catching and keeping so many more fish was somehow suspect.

 

As the discussion ended, another long-time commercial fisherman declared, “The striped bass will be here after you’re gone.” He offered no facts to support his opinion but still, we can only hope that he’s right.

More recently, the Montauk Boatmen and Captains Association posted a petition on Change.org, challenging the Bass Board’s emergency action. The petition notes that “more than 75% of our charter boat fleet focuses the bulk of their season on striped bass fishing…Striped bass fishing is truly the ‘bread and butter’ for most of our for-hire fishing fleet.” The petition then goes on to characterize the emergency measures as “drastic, unreasonable, and unnecessary,” and “preposterous” as well.

 

But it never explains why, at least from the bass’ perspective.

Instead, the objections to the emergency action were couched in purely economic terms. The state of the striped bass stock was never mentioned. It was almost as if the fleet was trying to convince itself that if fishery managers took care of their economic concerns, the bass would somehow take care of themselves.

Unfortunately, biology doesn’t work that way. Fishermen can’t catch fish, whether for sale or for pleasure, if those fish have never been spawned. Overfishing will not lead to a rebuilt stock. Fishing mortality must be reduced to a level that, given current recruitment levels, allows the stock to rebuild.

Fishermen can tell themselves that the emergency measures aren’t needed to rebuild striped bass. They can try to make themselves believe that the bass are doing just fine. But peer-reviewed science, and the bass themselves, are telling us something very different.

We would all do well to listen.

Or we could find ourselves whistling past a very different sort of graveyard.

-----

This essay first appeared in “From the Waterfront,” the blog of the Marine Fish Conservation Network, which can be found at http://conservefish.org/blog/


No comments:

Post a Comment