August 17, 2012 — The following is an excerpt from a letter to the ASMFC Delaware Commissioners from Dr. Amy Roe, Conservation Chair for the Delaware Chapter of the Sierra Club:
Re: Amendment 2 to the Interstate Fishery Management Plan for Atlantic Menhaden
Dear Commissioners,
The Delaware Chapter of the Sierra Club thanks you for your vote in support of releasing for public comment Amendment 2 to the Interstate Fishery Management Plan for Atlantic Menhaden.
Menhaden are thought to be at an all-time low in abundance, with populations estimated at less than ten percent of known historic levels. The continuation of intensive menhaden fishing in the purse seining fish reduction industry in an already collapsed fishery places the vitality of the coastal aquatic ecosystem, including all the predators that depend upon menhaden, at risk.
The lobbying activities of Omega Protein Corporation in the scientific review of menhaden are a concern, as they have introduced new politics into the technical understanding of menhaden and its potential to recover from intensive overfishing. Omega Protein’s scientists are introducing new data and statistical models for menhaden research that have not yet undergone the rigors of scientific falsification in the menhaden fishery. These methods, including domeshaped selectivity and aerial surveys outside of the commercial fishery area, should undergo the same rigorous scientific scrutiny as any other fishery management method before such findings are employed in the development of targets or fishery management plans.
Analysis: In a letter to the Delaware Commissioners of the Atlantic States Marine Fisheries Commission’s (ASMFC) Atlantic Menhaden Management Board, Dr. Amy Roe, Conservation Chair of the Sierra Club’s Delaware Chapter, writes that, while there is considerable uncertainty in current menhaden fishery data, the Sierra Club supports restrictive management action on the fishery. Dr. Roe writes, “…continued delays while the logistics of the scientific modeling of menhaden are being worked out will take time; time that menhaden do not have.”
This statement, along with the Sierra Club’s contention that menhaden need to, “recover from intensive overfishing,” implies that overfishing is a frequent and recent occurrence in the fishery. However, according to the 2010 ASMFC peer-reviewed benchmark stock assessment, in the last fifteen years for which there is data, overfishing has only occurred twice. The last recorded instance of overfishing was in 2008, when the fishery was just .4% over the threshold determined by the ASMFC. There is currently no reliable data for fishing activity in the last four years, and the exact status of the menhaden stock is not known.
The letter describes how scientists working in conjunction with Omega Protein are introducing, “new politics into the technical understanding of menhaden,” and new statistical models into the menhaden management process. One of the “new” statistical methods that the letter mentions is a proposed change to the fishery’s selectivity curve, a representation of the age composition of the fish available to be caught by the menhaden fishery. The current selectivity assumes that all menhaden over the age of three are equally likely to be caught, creating what is called a flat-topped selectivity curve. However, the selectivity change being proposed might better reflect the actual age distribution of the fishery. When menhaden reach the ages of four and five, many of them migrate to the North Atlantic in the summer months. This makes them unavailable to the bait and reduction fisheries, which operate mostly from North Carolina to southern New Jersey, with the majority of fishing occurring in and around the Chesapeake Bay. The proposed changes to the selectivity curve would account for this, as the curve would show the availability of fish older than three decreasing. This is known as “dome-shaped” selectivity.
The suggestion that dome-shaped selectivity be considered for use in the menhaden assessment did not originate with reduction industry scientists. The proposed addition of dome-shaped selectivity was recommended by the review panel of independent experts in the 2010 benchmark stock assessment. In addition, experts associated with the industry were encouraged to participate in the menhaden Technical Committee meetings as public commentators earlier this year. These leading experts in stock assessments contributed valuable information to the management process. As the Sierra Club recognizes, the most recent 2012 menhaden assessment update is seriously flawed, and is not considered an accurate estimation of the current stock. Suggestions to improve the assessment model, such as doming, need to be considered before any drastic management measures are taken.