Mesh size and effort changes in multispecies fisheries in ICES Divisions Vlllc and IXa.

Different simulations varying trawl mesh size and effort changes for several fishing units in ICES Divisions VIllc and IXa were carried out. Landings included in the analysis represent most of the catches in the southern area defined as the management unit for hake, megrim; monkfish, horse mackerel, blue whiting and mackerel. Three Nephrops stock s in Divisions Vlllc and IXa are also included. These species are mainly exploited by Spanish and Portuguese fleets, using various fishing gears to exploit different fractions of the populations, and for this reason nine fishing units were used in the analysis