Évolution et suivi des captures de trois espèces marines vulnérables Mérou Epinephelus marginatus, Denti Dentex dentex et Corb Sciaena umbra dans les pêcheries de Mostaganem

Abstract

This study is interested in the evolution and monitoring of the catches of three vulnerable marine species dusky grouper Epinephelus marginatus, denti Dentex dentex and corb Sciaena umbra in the fishery of Mostaganem, which these species present a vulnerable situation in the whole Mediterranean basin. The work was divided into two main parts : A survey targeting 76 professional and recreational fishermen, inquiring about the development of the catches and landings of the species studied, whose situation indicates a remarkable decrease in the catches of these species, leading to occasional to rare catches during the last years, and a followed in the field, of which we collected measurements for the study of the growth and the parameters of exploitation. Samples of 25 and 22 specimens were collected respectively for dusky grouper and common dentex, which provided the parameters L∞ = 157 cm and K = 0.20 /year for E. marginatus, and L∞ = 97.75 cm and K = 0.20 /year for D. dentex estimated by the subprogram Equal Surface Responses of the ELEFAN I program. The size-weight relationship indicates isometry for brown grouper and common dentex, i.e., weight grows in the same manner as length. The very small number of fish collected during the sampling period confirms the critical situation of the three species in question, which require special attention for these stocks.