Sunday, July 6, 2014

AN ILLUSION OF ABUNDANCE

It’s no secret that striped bass are harder to find than they used to be. 

Most anglers along the striper coast are complaining that fish are harder to come by this year, and a benchmark stock assessment (updated in December of last year) presented to the Atlantic States Marine Fisheries Commission notes that

“Female [spawning stock biomass] grew steadily from 1982 through 2003 when it peaked at about 78 thousand metric tons.  Female SSB has declined since then and was estimated at 58.2 thousand metric tons [at the end of 2012].  The SSB point estimate in 2012 remained just above the threshold level of 57.6 thousand metric tons and indicates that the striped bass are not overfished.  However, given the error associated with the 1995 and 2012 values, there is a probability of 0.46 that the female spawning stock biomass in 2012 is below the threshold...”
In other words, what anglers are seeing on the water is reflected in the scientists’ numbers.  Striped bass abundance is sliding downhill, and there is a 46% chance that bass were already overfished in 2012.

We don’t know for certain where things stand this year, but given that the spawning stock biomass sure didn’t increase in 2013, it’s pretty safe to say that the stock is in worse shape right now than it was in 2012.

So if you wanted to bet that the female spawning stock biomass of striped bass is already overfished—to be technical, that it had dropped below the spawning stock biomass threshold—don’t expect me to bet against you.

Even so, if you happened to be on the South Shore of Long Island over the past few weekends, it might have seemed as if the bass weren’t in any trouble.  Ridiculous numbers of truly large bass—some in excess of 50 pounds—are being caught by anglers fishing around the pods of bunker (a/k/a menhaden) that are passing a few hundred yards south of the beach.

Some days, the fish are picky, and not too many are caught.  On others, a single boat may land upwards of two dozen fish, with few weighing less than 30 pounds.

This isn’t a “sharpie’s” bite.  It’s what some of us call “stupid fishing,” that doesn’t require any more skill than it takes to lob a weighted treble hook into the middle of a school of bunker, snag a fish and then let it swim around—often for a very short while—until a striper ingests it.

Experienced striped bass fishermen are catching their share.  But a lot of very average anglers are catching fish, too, and a many of those anglers, who haven’t put in much time chasing striped bass, are interpreting their sudden success as a sign that the striped bass stock is healthy.

We saw the same thing last year, when a big body of sand eels took up residence off Fire Island and, for a month or so, private boats and for-hire vessels from as far away as Brooklyn—some say they saw at least one party boat from New Jersey—found fast action with striped bass that homed in on the bait.

Folks argued that, with party boats limiting out on an every-day basis, the bass stock must be doing pretty well.

But—wait just a minute—did you notice me mentioning boats from Brooklyn and maybe even New Jersey?

They were running all the way to Fire Island, burning a lot of fuel and spending a couple of hours in transit, because there was nothing closer to their own local ports.  During late October and early November of last year, if you wanted a striped bass anywhere along the South Shore of Long Island, you ran east of Fire Island Inlet.

And so far year, you run to the bunker schools.  The surf has been pretty dead, the bays have been quiet and the inlets have given up very few fish.  Most days, the only game in town has been the bunker schools.

And that is a very bad sign.

Even so, people who happen to be fishing where the fish happen to be are catching a lot of bass, and it can be hard to convince them that something is wrong.

Up in New England, we’re seeing the same sort of thing with cod.


“The Gulf of Maine Atlantic cod (Gadus morhua) stock is overfished and overfishing is occurring.  Spawning stock biomass (SSB) in 2011 is estimated to be 9,903 [metric tons] or 10,221 mt which is 18% or 13% of the SSBMSY proxy (54,743 mt or 80,200 mt) [depending on which of two population models is used].  The 2011 fully selected fishing mortality is estimated to be 0.86 or 0.90 which is about 4 or 5 times the FMSY proxy (0.18 for both models).”
In other words, Gulf of Maine cod are in pretty rough shape, but you wouldn’t know it to hear some fishermen talk.  

They’re catching a lot of fish, don’t think that there is any problem, and have been saying things such as

and


As in the case of striped bass, it was all about an abundance of forage fish that concentrated the predators in one place, although in the case of cod, it was also about a lack of forage everywhere else.

NOAA Fisheries found that, beginning about ten years ago, herring—which once were the predominant forage for Gulf of Maine cod, began to disappear (as an aside, folks such as the Herring Alliance have been trying to correct that problem, and have had some hard-earned success).

At that point the cod—like last fall’s striped bass off Fire Island—switched over to sand eels.  Most of those sand eels were concentrated on a small section of Stellwagen Bank, and the cod—again like the striped bass off Fire Island—bunched up on a 100-square-mile piece of the bank, where they were easy to catch and gave the illusion of abundance, although cod were scarce in the other 20,000-plus square miles of the stock’s historic range.

As NOAA Fisheries pointed out,

“The trends in cod abundance in this small region were not truly reflective of the overall resource at the time.”
Yet it’s hard to convince a fisherman of that when he’s filling his boxes with cod, just as it’s tough to convince a lot of folks new to the fishery that the striper is headed for trouble when they just put a pair of 40-pound bass in the cooler.

Those folks weren’t around in the late 1970s and early 1980s, when the striped bass stock last collapsed.  

They don’t remember that even as the fish were disappearing just about everywhere, anglers on Block Island and up on Cape Cod were having some of the fastest action they had ever known with some truly large striped bass. 

Back then, too, they couldn’t see past the big fish they were catching to recognize that bad times had already come.

But if we are to fix our fishery problems—for striped bass, cod, and everything else—we need to recognize that so long as fish swim in the ocean, there will be those times when by some accident of bait, timing and environmental conditions, fish will concentrate in one place and provide the illusion of abundance, even in times of scarcity.

We must reject that illusion, and remember that the true test of the health of a stock isn’t found in the scattered places where fish are abundant, but in the empty places where the fish used to be.


And then we have figure out how to fill those big empty places with fish once again.

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