Estimates of catch and potential yield for the riverine artisanal fishery in The Gambia, West Africa

Abstract

The limnological characteristics of the Gambia River have resulted in a seasonally dynamic fish composition and a complicated artisanal fishery. The estimate of catch (2700t year−1) for the fishery during 1980 is low compared to potential yield as predicted by empirical relations with river channel length, drainage basin area, floodplain area, and the morphoedaphic index. A decrease in catch per unit effort was weakly correlated to increasing effort during March‐July in the lower river. For the overall Gambian fishery, however, temporal changes in catch per unit effort were not correlated with changes in effort. Predictions of yield are consistently higher than catch estimates for the fishery and suggest underexploitation of the stocks. Many assumptions of the predicting techniques, however, are unsatisfied, and the year‐to‐year variability of the Gambia River catch is unknown. Consensus seems to emerge if only crude evaluations of a fishery are needed, but the predicting techniques do not provide the degree of resolution required for most management decisions.