Fish Population Structure and its Relation to Fisheries Yield in Small Reservoirs in Côte d'Ivoire
Résumé
Lack of reliable data on the fisheries of northern Côte d'Ivoire reservoirs is a major limitation for management of the fish stocks. As individual reservoirs cannot be studied due to the high costs and lack of trained investigators, empirical and production models have to be used to evaluate exploitation rates and fisheries potential. Daily yield (DY, in kg fishing day-1 year-1) and total catch (TC, in kg year-1) appear to be better descriptors than annual yield (in kg ha-1 year-1). TC is related to variables linked to nutrient availability (watershed area, conductivity and Morphoedaphic Index). DY is related to fish species richness and to reservoir area, indicating that fish population structure could be a key to understanding the patterns observed. Correlation between fish population structure and yield was significant. It was hypothesised that overall catch, TC, is related to nutrient availability, but that catch per unit effort is related to the presence of given species in the reservoirs, and particularly to the presence of bottom feeding species.
Domaines
Biodiversité et Ecologie
Origine : Fichiers produits par l'(les) auteur(s)
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