Potential benefits from improved selectivity in the northwest Mediterranean multispecies trawl fishery

Abstract

The management scheme in the northwest Mediterranean multispecies demersal fishery is based largely on technical measures such as minimum mesh and landing sizes. However, selectivity of the trawls used is poor, and large numbers of juvenile fish are caught. We assess the consequences of improved gear selectivity for European hake, Norway lobster, poor cod, and greater forkbeard by assuming that the whole fleet would switch from the current 40 mm diamond-mesh to a 40 mm square-mesh (SM40) codend. The results suggest that, immediately after implementation, the yield-per-recruit (Y/R) would be reduced by up to 20% for the three fish species but that, within five years, the Y/R of European hake would increase by >50%, provided fishing effort did not change markedly. For poor cod and greater forkbeard, the comparable increases would be more moderate, whereas for Norway lobster, the gains would only be small. Overall, marked long-term benefits might be obtained by changing to SM40 codends. © 2007 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.