Fishing year 2012 brought significant harvest reductions to the northern shrimp fishery with managers reducing the total allowable catch (TAC) by 50 percent to 2,000 mt. The reduction comes in the wake of a 48 percent overage of the 2011 TAC, emergency closures in 2010 and 2011, and annual declines in the biomass since 2007. However, members of both the scientific and seafood industries have questioned the outcome of the most recent stock assessment. Steve Cadrin of the School of Marine Science and Technology, UMass Dartmouth (SMAST) performed an alternate assessment with a higher natural mortality rate (M) and the results suggest the TAC could be set as high as 4,500 mt.
GMRI oversaw an independent evaluation of Cadrin's alternative assessment, which was carried out by Michael Sissenwine, former director of the Northeast Fisheries Science Center (NEFSC) in Woods Hole and former chief scientist at NMFS. The analysis concurred with Cadrin that a natural m ortality rate of M=0.60 is more scientifically defensible than the M=0.25 used in the current stock assessment.
However, Sissenwine's analysis also suggests that the annual and long-term surplus production from the Gulf of Maine shrimp stock since 2006 has been less than previously estimated, and therefore managed below a biomass necessary for maximum sustainable yield for the past five years. As a result, current estimates of stock abundance may be over-estimated. Finally, Sissenwine indicates that oceanographic and climatic influences on northern shrimp production may have a greater impact on overall abundance than previously thought, and should be more closely examined and considered in determining future shrimp abundance and maximum sustainable yield.
Northern shrimp are managed cooperatively by Maine, Massachusetts, and New Hampshire under the Interstate Fisheries Management Program of the Atlantic States Marine Fisheries Commission. These three states form the Northern Shrimp Section (Section), which is responsible for developing and carrying out actions under the fishery management plan (FMP). The case to increase the TAC was presented by industry at a meeting of the Section following the Cadrin and Sissenwine analyses. At this meeting the Section increased the TAC by 10 percent for the current season, a measure that reflects a cautionary approach in light of the scientific uncertainty.
Last fall, the Section adopted Amendment 2 to the Northern Shrimp FMP, which expands the regulatory toolbox to include weekly reporting by dealers, trip limits, trap limits, and days-out. Additionally, a range of limited-entry options may be pursued through the addendum process of Amendment 2, including license limitation and catch shares. The Section will continue to meet throughout 2012 to discuss additional management options.
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