Impact of Large Mesh Codend and Escapee Mortality: The Example of Haddock in New England Multispecies Trawl Fishery

The minimum mesh size in the United States Northeast multispecies trawl fishery has been gradually increased over the last 30 years. In 1953, the International Commission for the Northwest Atlantic Fisheries first implemented the 114 mm minimum codend mesh, which remained in place until 1977 when the New England Fishery Management Council (NEFMC) took over management responsibility. The mesh size was then gradually increased to 130 mm in 1977, 140 mm in 1983, 152 mm in 1994, and 165 mm in 1999. Now even 187 mm mesh size codends are being used by some fishermen to target the largest Atlantic cod. Along with gradual increase in codend mesh size, a larger and larger proportion of fish that enter a codend is allowed to escape. In the case of haddock (Melanogrammus aeglefinus) in the western Gulf of Maine, 92-98% of fish escaped through the 165 mm mesh size codends. What is the fate of the fish that escape through the codend meshes? What is the possible impact of these large mesh codends and the resulting unaccounted mortality on the overall fishing mortality of the species? This presentation will explore possible consequences with the Gulf of Maine haddock as an example.