After spending over 50 years on and around the water, I have realized that without strong fisheries laws and effective conservation measures, the future of salt water fishing, and America's living marine resources, is dim. Yet conservation is given short shrift by national angling organizations and the angling press. I hope that this blog will incite, inform and inspire salt water fishermen to reclaim their traditional role as the leading advocates for the conservation of America's fisheries.
Sunday, December 6, 2015
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.
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.
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, theGarden 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.
“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 relevanteconomic, 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?
“…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.”
“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.
This post originally appeared on the blog of the Marine Fish Conservation Network, "From the Waterfront", which may be found at http://conservefish.org/blog