WASHINGTON (Saving Seafood) August 28, 2012 — The Atlantic States Marine Fisheries Commission (ASMFC) is currently considering potentially drastic cuts to the Atlantic menhaden harvest, as a result of a 2010 assessment that showed overfishing. Not much data are available on the current state of the fishery, as the most recently available assessment from 2012 was deemed severely flawed by the ASMFC’s Menhaden Technical Committee, and is an unreliable gauge of the health of the menhaden stock. Outside of the 2012 stock assessment, there are new data on menhaden that potentially contradicts the overfishing designation, showing that the population may be twice as high as current estimates. There is precedent for regulatory agencies to consider such data, most notably in the late 1990s with the scallop fishery and in the early 2000s with the monkfish fishery.
The additional data, an aerial survey of the North Atlantic conducted by fish stock survey expert Dr. James Sulikowski of the University of New England, showed a significant number of menhaden in northern waters, areas menhaden are known to inhabit but for which little data were previously available. The survey results were analyzed by Dr. Doug Butterworth, a world-renowned stock assessment scientist from the University of Cape Town in South Africa, and Dr. Alexia Morgan, who has consulted with organizations such as the New England Aquarium, the Blue Ocean Institute, and the Pew Environment Group. The results of the North Atlantic aerial survey were compared with contemporaneous aerial observations made by spotter pilots in the southern portion of the menhaden fishery’s range. Based on these comparisons, Drs. Butterworth and Morgan found that menhaden stock biomass may be twice as high as measured in the currently-used 2010 assessment, which found that overfishing is occurring but that menhaden are not overfished.
Using single-year, non-peer-reviewed data to temper the extent of new regulations is not unprecedented in fisheries management. In 1998, harvest cuts were enacted that would have been drastic enough to effectively shut down most of the New England scallop fishing fleet. Before the cuts in fishing opportunities scheduled for 1999 went into effect, the University of Massachusetts, Dartmouth Center for Marine Science and Technology (now SMAST), the Fisheries Survival Fund, and NMFS collaborated on a scallop survey in areas that were then off-limits to fishing. The study revealed high scallop abundance in the closed areas and, as a result, the New England Fishery Management Council (NEFMC) decided to keep the fishery at status quo through successive framework actions over the next few years.
Similarly, in 1999, after years of poor surveys, regulators developed a four-year plan to reduce overfishing and rebuild the Atlantic monkfish stock that was to have resulted in a zero possession limit in year four. Concerned for their livelihood and believing the stock to be in much better shaped than apparent in the NMFS annual survey, Brooklyn-based monkfish processor Marc Agger formed with other members of the industry the Monkfish Defense Fund (MDF). The MDF retained an independent scientific advisor, Dr. J. J. Maguire, who helped design and implement a cooperative trawl survey, which, according to Monkfish Framework 1, “provided a wealth of new information and allowed a more complete assessment of the monkfish resource than had been previously possible.”
Although the survey methodology and results had not been peer reviewed, the information gathered was used in the January 2002 Stock Assessment Workshop, which concluded the stock was in much better shape than previously thought. The industry survey’s results were also used to justify a one-year postponement of the fourth-year harvest reduction until more information was collected to get a complete picture of the health of the monkfish population. The monkfish survey sponsored by the MDF was conducted two subsequent times, with each survey showing consistently higher estimates than the official trawl survey.
The ASMFC recognizes the inadequacies of the existing menhaden stock assessment data. The Menhaden Technical Committee, the arm of the ASMFC that reviews menhaden stock assessments, concluded that the 2012 menhaden assessment is not a suitable guide for management decisions. Most notable among the flaws identified by the Technical Committee is the appearance of a retrospective pattern, meaning that the estimates in previous population assessments contradict the population estimates in the most recent assessment, and need to be revised in order to fit the more current data. The appearance of a retrospective pattern in a stock assessment indicates that some of the assumptions that are built into the assessment model are incorrect. It is a sign the model is no longer working and needs to be revised.
The Atlantic menhaden fishery currently faces a situation similar to those previously faced by the scallop and monkfish fisheries. Regulators are currently dealing with a data-poor situation and are considering large cuts to the menhaden harvest, while recently available data suggests that these cuts might not be necessary, or might not need to be as large. In previous cases, non-peer-reviewed data from a single year was used to delay potentially drastic management decisions. Adopting a similarly cautious approach could provide time to allow the ASMFC to acquire more comprehensive information on the health of Atlantic menhaden.
Additional resources
Areas of Concern in the ASMFC's 2012 Atlantic Menhaden Assessment Update
For a definition of "retrospective pattern", see our glossary.