Selectivity curves for the major species are available and have been published (Fontana, 1974, Franqueville and Lhomme, 1979). CECAF has inventoried the official regulations (Ansa-Emmim, 1979). Regulations, however, are often not respected; little or no attention is paid to CECAF recommendations, and monitoring by coastal countries remains problematic especially for foreign flag vessels.
A detailed analysis should be carried out and concrete proposals made CRODT (Senegal), which has the necessary staff and data, should devote some effort to this problem. In addition, all countries concerned should attempt to find out what mesh sizes are really being used by the fleets exploiting their waters. CECAF should distribute gauges (ICES or others) and accelerate the mission of a consultant to train national technicians in Guinea, Guinea-Bissau, Mauritania and Gambia. Let us recall that “the general feeling is that meshes actually used for the soft bottom coastal fauna (Sciaenidae, Polynemidae) are too small. Studies conducted in Senegal show that for many species 62 mm stretched would be desirable” (FAO, 1979).
Fig. 1 Evolution of local and Ivorian trawlers cpue in Sierra Leone for some important species (1966 cpue percentages used as reference)
