SPATIAL AND TEMPORAL VARIATIONS OF MANGROVE FISH ASSEMBLAGES IN MARTINIQUE (FRENCH-WEST-INDIES)

A study of the mangrove fish fauna in a bay of Martinique Island (Fren ch West Indies) was carried out at different seasons during two consec utive years. Fishes were sampled with specific hoop-nets in the coasta l areas at and stations.A total of 87 species was collected in the bay . Most individuals were represented by small-size specimens and juveni les. The overall species richness varied according to the stations and the sampling periods. The biomass and number of individuals were vari able according to the location but remained stable in time. A factor c orrespondence analysis and a hierarchical clustering with median links were used to follow the evolution of the stations in space and time. Two types of stations were differentiated: the stations characterized by the mangrove and those under the influence of seagrass beds. A seas onal cycle, opposing the dry periods to the others, was observed. Thus , it seems that the use of the mangrove habitat by the fishes is optim ized through a complete reorganization of communities in terms of spec ies composition whereas the overall number and biomass remain stable. This model remains valid even for the most constraining biota of the m angrove ecosystem inhabited by a small number of well adapted species.