Un modèle global avec quantité de biomasse inaccessible liée aux conditions environnementales: Application aux données de la pêche ivoiro-ghanéenne de Sardinella aurita

Abstract

It is generally assumed, when using a surplus production model, that production of biomass is described as a function of exploited biomass. If a constant quantity of biomass is unaccessible, this assumption may be false. We propose here two formulations of production models assuming the existence of a quantity of unaccessible biomass. When this quantity change during the history of a fishery, such models may be useful. Using environmental data in Ivory Coast, this approach describes the fishery of Sardinella aurita in Ivory Coast and Ghana from 1966 to 1980. The suggested adjustements are effective but they do not allow us to choose between the two formulations, each of them leading to different conclusions for stock management. © 1988 IFREMER-Gauthier-Villars.