Thursday, July 24, 2014

MANAGING FOR LIFE

The Magnuson-Stevens Fishery Conservation and Management Act is, without question, the most comprehensive and most successful fishery management law in the world.

Under its aegis, at least since the Sustainable Fisheries Act of 1996 became law, overfishing has been sharply reduced and many overfished stocks have been restored to health.

However, like anything crafted by man, Magnuson isn’t perfect.  Its biggest flaw may be that it manages dead fish, rather than live ones.

This is what I mean.

Under Magnuson, management parameters are ultimately defined in terms of yield. Overfishing is

a rate or level of fishing mortality that jeopardizes the capacity of a fishery to produce the maximum sustainable yield on a continuing basis,”
while National Standard One says that stocks should be managed for “optimum” yield, which is
“the amount of fish which—
(A) will provide the greatest overall benefit to the Nation, particularly with respect to food production and recreational opportunities, and taking into account the protection of marine ecosystems;
(B) is prescribed as such on the basis of the maximum sustainable yield from the fishery, as reduced by any relevant economic, social, or ecological factor; and
(C) in the case of an overfished fishery, provides for rebuilding to a level consistent with producing the maximum sustainable yield in such fishery.”
It’s all about “yield”—how many fish may be safely killed, rather than how many fish ought to be kept alive.

Yes, I know that an overfished stock is generally defined in terms of biomass—live fish in the water—but even there, an overfished stock is one that is too small to produce maximum sustainable yield.

Despite the references to “marine ecosystems” and “ecological factor” in the definition of “optimum” yield, when you get right down to it, the effectiveness of management actions is measured in terms of dead fish, not live ones.

Think what management would look like if we took the other tack, and managed for life instead.

I’m writing as an angler, so let’s consider a popular angling species—it might be bluefish, king mackerel or perhaps Pacific rockfish—and think about what the populations should look like.

First, as I and others have written before, anglers want fish in abundance.  That means keeping enough fish in the water that anglers, throughout the species’ range, have a good chance of encountering some at any time during the season.  What constitutes “some” fish will differ from species to species—you would expect to catch a lot more Spanish mackerel than, say, cobia—but whatever the species, the chances of an encounter would be pretty high.

But mere abundance is just not enough.  We’d also want to give some of those fish a chance to live long enough to get big. 

That’s inefficient from a commercial perspective, where any fish that dies of old age is deemed wasted and a population that quickly produces big numbers of little fish may be more profitable than one in which harvest is delayed to produce larger individuals.  However, anglers have always been intrigued by big fish, and the sort of management that produces big fish is also the kind of management that leads to the healthiest stocks. 

That’s because a population that includes a good number of larger individuals, the sort that fisheries scientists sometimes affectionately refer to as “BOFFs”—Big, Old, Fat Fish—usually has a spawning stock made up of fish of many different sizes belonging to many different year classes.  Such a stock, which is not dependent on just one or two year classes for its spawning success, is inherently more resilient and better able to shrug off transient environmental conditions that lead to a few years of poor recruitment.

Thus, rather than managing for “optimum yield,” which pegs harvest at or near the highest sustainable levels without regard for the structure of the stock, managers should instead be seeking “optimum” abundance and an “optimum” stock structure, by setting a “permissible harvest level” which assures that such an optimized stock can be created and maintained.

And no, that is not some sort of radical dream.  It’s more or less how whitetail deer are managed today, with tools such as doe permits to manage abundance and recruitment, minimum antler requirements to allow some bucks to grow old, etc. 

“Quality deer management” has been around for a long time, and maybe it’s past time for “quality fish management” to make its appearance.

Once we accept the fact that fish are wildlife, it all makes perfect sense.

A different approach is needed for creatures near the base of the food web, which provide the food that other fish, as well as birds and marine mammals, need to survive.  They’re lumped together in the broad category of “forage fish,” although some are not fish—squid and many crustaceans come to mind—and some are not simply forage.  Atlantic mackerel feed people as well as bluefin tuna, while Pacific pollock are critically important to both commercial fishermen and Steller sea lions.

In such cases, managers first need to ensure that there are enough fish around to fulfill their role in the marine food web.  Then, there needs to be enough left over to provide a sustainable and well-structured breeding population.  After that, once again, the “permissible harvest level” kicks in.

It’s trendy to call such approach “ecosystem management,” but that’s probably a misnomer.  Ocean ecosystems are vast, complex systems that encompass everything from viruses to blue whales, and no one is capable of managing all of that.

And calling for “ecosystem management” always brings out the clowns who pretend to go along, then follow up by claiming that the red snapper—or the cod, or striped bass or red drum—are getting too numerous, and throwing the ecosystem out of whack, and that in the name of “ecosystem management” they should be allowed to go out and kill a bunch to bring things back into balance, forgetting that fish got along just fine, without that kind of “help,” for something like 450 million years.

No, I think it’s better to just refer to it as “live fish management,” or maybe more simply, “managing for life.”

Because life, in all its diversity and its abundance, is the ultimate good.



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