Thursday, April 4, 2019

POINTING FINGERS, DODGING BLAME


If you spend any time at all around fishery management meetings, you’re already familiar with the “not me” syndrome. 

It takes a number of forms, but in the end, they all share one common trait:  When measures to increase the abundance of some species of fish—any species of fish—are proposed, a fisherman will stand up and say “Don’t put more restrictions on me!  I’m not the problem!  If you want to have more fish, you have to do something about the [fill in the blanks]”

Exactly what species, or oceanic condition, might fill in those blanks varies from place to place, and from fishery to fishery.

On the East Coast, fishermen often blame the striped bass for the decline of other species.  Bass are large fish that will, at some point, eat just about anything that they can fit into their mouths, from lobster to tautog and from blue crabs to winter flounder, so when any of those species slip into decline, there is always some fishermen somewhere what are willing to stand up and say “The striped bass did it!”

And, just about every time, that same bunch of fishermen will then offer to do the public a favor by killing off more of the supposedly over-abundant predators.


“There is no scientific data to support a supposition that Striped Bass predation is causing a significant depletion of the Chesapeake Bay blue crab population.  In fact, studies performed in Maryland and Virginia to assess the diets of striped bass indicated that blue crabs make up a small percentage of the average striped bass diet.”

“would harm the crab population, and would not bring watermen any overall economic benefit.”

Now, with the striped bass population overfished, it's harder to blame bass for other species' problems.  In fact, it seems that the tables have turned, and there are now some folks looking for a scapegoat for the striped bass' decline.

One group has decided that the current dearth of striped bass can be blamed on the seemingly inoffensive cownose ray.


“The science of sustainable seafood, explained.”

“We were founded by a group of fisheries scientists led by Dr. Ray Hilborn.  We are run by a small staff, all of who [sic] have advanced degrees in some element of fisheries.  All of our posts, features, and editorials are edited and fact checked by experts.”
That sounds like an impressive set of credentials.  


At any rate, with respect to striped bass, Sustainable Fisheries starts by saying

“In February, a much-anticipated Atlantic striped bass stock assessment was presented to the Atlantic striped bass stock assessment was presented to the Atlantic States Marine Fisheries Commission (ASMFC).  The preliminary results were incomplete due to the government shutdown, but the outlook is bleak on a fishery well-known for its recovery in the early 2000’s.  With numerous fishery news outlets reporting on this story, we wanted to provide a historical perspective on the fishery and offer some considerations for policy makers on how to more effectively manage this resource going forward.”
Again, it sounds good.  But after that first paragraph, things start really heading downhill.

One of the most striking aspects of Sustainable Fisheries’ striped bass page is that the only time the terms “overfished” and “overfishing” is in reference to the 2016 stock assessment update, which found that neither applied to the bass back then; Sustainable Fisheries never explicitly states that, according to the benchmark 2018 assessment, the striped bass stock is overfished and undergoing overfishing today.

Instead, it merely notes that

“Female spawning stock biomass…will fall below the target threshold [sic] for the first time since 1995, if the preliminary assessment holds true.  The threshold is 91,436 metric tons, and the assessment estimates that the [spawning stock biomass] fell to 68,476 in 2017.”  [emphasis added]”
Leaving aside the fact that there is no such thing as a “target threshold”—the biomass target represents the stock’s optimum abundance level, while the biomass threshold defines the point where the stock becomes overfished—the website seems to make a determined effort to describe an overfished striped bass stock without ever coming out and actually using that term.

By using the phrase “if the preliminary assessment holds true,” Sustainable Fisheries seems to be making an intentional effort to cast doubt on the conclusions of the 2018 benchmark stock assessment, a theme that carries forward in the next paragraph, where it notes that the outcome of the 2018 assessment

“directly contradicts the ASMFC’s 2016 claim that ‘the 2016 Atlantic striped bass stock assessment indicates the resource is not overfished nor experiencing overfishing…But piecing together various industry reports and ongoing studies provides a more complicated picture, even before the most recent assessment is released in a few months.”
To that end, it also perpetuates the message that striped bass might be more abundant than the assessment suggests, but just staying farther offshore, saying

“the closure of the EEZ to all striped bass fishing effort has meant minimal data collection outside the 3nm boundary.  Again, fish don’t respect jurisdictional boundaries, and if a nice pocket of warm water exists 4nm miles from shore, striped bass will find it, while stock assessments may not.”
Again, the goal of such comments seems to be to impeach the conclusions of the 2018 assessment.

But the real kicker comes at a different point in the discussion.

The 2018 assessment clearly points to overfishing, combined with years of below-average recruitment, for the striped bass’ current decline.  And it’s been recognized for more than a decade that weather during the spawn drives recruitment success.

But Sustainable Fisheries suggests a different cause for below-average recruitment: cownose rays.

“2012 yielded the lowest recruitment since the stock rebuilt.  Some blame the addition of invasive species to key juvenile striped bass estuaries, namely those connected to Chesapeake Bay…recent invasive species have been disturbing important food webs.  A likely culprit is the cownose ray, which isn’t technically an invasive species, but has recently appeared in record numbers in the Chesapeake Bay.  This ray has no natural predators in the Bay, and prefers a diet of bivalves and crabs—precisely the foods juvenile striped bass need to survive.”
Except that juvenile striped bass don’t feed heavily on crabs—although the eat them from time to time—and don’t really feed on bivalves.  They certainly don't "need" crabs and bivalves "to survive."  Even Sustainable Fisheries admits, elsewhere on the same page, that

Menhaden are a critical food source for striped bass, especially juveniles in and around the Chesapeake Bay. [emphasis added]”
That statement is more in accord with the accepted science. 


“During different stages in their life cycle, striped bass feed on zooplankton, fish larvae, insects, worms, amphipods, Bay anchovy, spot, menhaden, herring, shad, white perch, and yellow perch.”
Nowhere does NMFS suggest that bivalves and crabs are critical to the juvenile striped bass’ diet.  And nowhere does it suggest that striped bass and cownose rays compete, at any time, or at any place, for food.

It seems that Sustainable Fisheries may have a credibility problem. Reading its "Atlantic striped bass" page, it appears that Sustainable Fisheries is more interested in sustaining the current level of striped bass landings rather than in sustaining the striped bass stock.

Although it claims to provide, and explain, the “science” of sustainable seafood, what it is really providing, at least with respect to striped bass, are excuses designed to mislead striped bass managers, and send them down the wrong path.

But if managers allow themselves to be misled, and head down the road that Sustainable Fisheries seems to be suggesting, we all will soon find, to our sorrow, that the Atlantic striped bass fishery isn’t sustainable any more.






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