On the dynamics of the Mauritanian small-pelagic fishery North-West Africa

Off Mauritania, North-West Africa, a pelagic fishery has operated for more than 30 years, with a recent average annual catch of about 400 000 tons. Ca tches are influenced by region and by seasonal hydrographic conditions. Yie lds of carangids (Trachurus trachurus, T. trecae and Decapterus rhonchus) a re significantly higher (p < 0.05) in the southern part of the Fishing zone than in the north, whereas the reverse is observed for Sardina pilchardus. Carangids are caught mostly during the transitional seasons (June-July and November-December), whereas clupeoids (S. pilchardus, Sardinella aurita an d Sardinella maderensis) are mostly taken during the cold (January-May) and warm (August-October) seasons. Market destination for the different fisher ies is a key factor in determining differences in species yields in the Mau ritanian upwelling region. Most fleets follow concentrations of carangids, even though other species may be more abundant elsewhere. Caution should be applied in treating cpue as an index of abundance.