Unmanaged Forage Fish: Does Optimum Yield Equal Zero?


Fisheries managers are finally paying attention to forage fish, the myriad species of small fish, squid and crustaceans that the predators need to survive.

At the federal level, the Pacific Fishery Management Council got the ball rolling with its Comprehensive Ecosystem-Based Amendment 1: Protecting Unfished and Unmanaged Forage Fish Species. That Amendment would prevent the creation of new fisheries for forage species that are managed at neither the state nor the federal level, until all of the relevant science, and the possible impacts of any new fishery, can be thoroughly examined.

Last October, the Mid-Atlantic Fishery Management Council voted to move forward with an omnibus amendment that would also prevent the creation of new fisheries until all of the implications can be thoroughly examined.

Those measures deal with currently unmanaged forage fish stocks, which have little current commercial or recreational value. However, a number of forage species are already either targeted or incidentally killed by existing fisheries, and have management plans in place.

Menhaden is probably the best example of a targeted forage species. Harvested for fertilizer in colonial days, menhaden currently support an industrial fishery that “reduces” the whole fish into various products ranging from poultry feed to lubricants.

Menhaden landings in the Atlantic and Gulf of Mexico totaled over 1.15 billion pounds in 2014, which is an awful lot of forage to remove from the ocean, even if menhaden are very abundant along much of the coast. The Atlantic States Marine Fisheries Commission (ASMFC) is now investigating “Biological Ecological Reference Points” to better manage menhaden as a forage species, although no management action is expected until after 2017.

ASMFC is also trying to rebuild collapsed stocks of alewives and blueback herring; populations of both species, collectively known as “river herring,” have declined sharply in most East Coast river systems, and many local fisheries have been shut down to promote a recovery.

However, ASMFC can’t do it all. River herring spend most of their lives out at sea, where they are frequently killed as bycatch in the Atlantic herring and Atlantic mackerel fisheries.

The New England Fishery Management Council implemented catch caps on river herring in the Atlantic herring fishery in an attempt to reduce such bycatch. However, in a move decried by fisheries conservation advocates, the Council voted to increase such caps at its October 2015 meeting, making it likely that more river herring will end up being killed.

Fortunately, the Mid-Atlantic Fishery Management Council has shown itself to be a better steward of river herring resources, setting meaningful caps in the Atlantic mackerel fishery that will shut down that fishery if the caps are exceeded. However, it failed to initiate a river herring management plan that recognized river herring as a “stock in the fishery,” something that the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens) would have allowed it to do. In opposing “stock in the fishery” status, the Garden State Seafood Association, which represents some large mackerel fishing operations, said

“the Council has established a catch cap on river herring species, as part of the Atlantic mackerel fishery specifications for the 2014 fishing year, which already threatens the industry’s ability to realize the Optimum Yield from the Atlantic mackerel resource, on a continuing basis, as required by National Standard 1 of the [Magnuson-Stevens Fishery Conservation and Management] Act…”

That’s an interesting statement, which deserves some serious thought.

For Magnuson-Stevens purposes,

“The term ‘optimum’, with respect to the yield from a fishery, means 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 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. [emphasis added]”

Thus, it’s not hard to argue that if the current annual catch limit of Atlantic mackerel would lead to an excessive bycatch of river herring, then the optimum yield in the mackerel fishery should be reduced, due to that ecological factor, to a level which makes it likely that any such bycatch will be adequately constrained.

But that just opens the door to another question. Whether we’re talking about river herring, Atlantic mackerel or other forage fish, just what constitutes optimum yield for forage species?

The Lenfest Ocean Program is a grant-making program that funds scientific research on a number of policy-relevant issues concerning the world’s oceans. A few years ago, a Lenfest-supported task force released a report entitled Little Fish, Big Impact: Managing a Crucial Link in Ocean Food Webs, which investigated that issue in depth.

It noted that

“…our food web modeling results revealed that fishing at a typical rate, [that produces maximum sustainable yield], often led to collapses of forage fish populations and large decreases in the abundance of dependent predators…

“Model simulations showed that forage fish populations and their dependent predators were reliably sustained when fishing pressure was half as high and forage fish biomass in the ocean was twice as large as traditionally practiced…

“Overall, our results support setting much more conservative targets and limits for forage fishery management than have been commonly recommended and applied in the past.”

NMFS generally concurs, noting in its National Standard One guidelines that

“consideration should be given to managing forage stocks for higher biomass than [the biomass needed to produce maximum sustainable yield] to enhance and protect the marine ecosystem.”

If such standards were applied to forage fish stocks, such as Atlantic menhaden and butterfish, that are already subject to management, harvests would have to be substantially reduced in order to meet the standards proposed in the Lenfest report. As the Garden State Seafood letter suggests, any such reductions are likely to face strong opposition from the fishing industry.

However, when it comes to currently unmanaged stocks, such as round herring or sand lance, which don’t support federal fisheries, why not go Lenfest one better and set optimum yield at zero? Wouldn’t the relevant “ecological factors”—the dependence of so many species of fish, marine mammals and fish-eating birds on such forage species—justify reducing potential landings from maximum sustainably yield down to zero?

And wouldn’t economic considerations also support such an action? It wouldn’t cost anyone as much as a cent in lost profits. But it would help to ensure that adequate forage would be available to a host of species important to the commercial and recreational fishing industries.

That sounds like a win-win situation.

So far, no one has suggested that optimum yield for unfished forage stocks should be set at zero; that would be a far more conservative standard than either the Pacific or Mid-Atlantic Councils has considered.

Even so, it may be the right thing to do.

About Charles Witek

Charles Witek is an attorney, salt water angler and award-winning blogger. Read his work at One Angler’s Voyage.

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