An Analysis of Fishing Selectivity for Northeast US Multispecies Bottom Trawlers

Observed production sets in multispecies fisheries are affected by regulatory incentives influencing spatiotemporal fishing decisions. Rights-based output controls can promote selective fishing; however, this ability may be limited and insufficient in achieving full utilization of catch quotas. We measure fishing selectivity for bottom trawlers catching federally regulated groundfish in the Gulf of Maine and Georges Bank before and after the introduction of rights-based output controls. Directional distance functions are applied to tow-level catch data collected by fishery observers to construct a measure of selectivity equal to the difference between strong and weak output disposal efficient production frontiers. Quantile regressions are then used to estimate the change in median selectivity associated with the introduction of catch share management, controlling for spatial, temporal, and individual factors. A significant improvement in selectivity was found for tows in Georges Bank following the 2010 management change, though production is still largely characterized by imperfect selectivity.