DISTRIBUTION OF BENTHIC MACROINVERTEBRATE COMMUNITIES IN RELATION TO ENVIRONMENTAL FACTORS IN THE EBRIE LAGOON (IVORY COAST, WEST AFRICA)

This paper aims to reveal the organisation and environmental variables affecting the spatial distribution of benthic macroinvertebrates in the Ebrie lagoon (Ivory Coast, West Africa). The organisation of benthic macroinvertebrates was recorded at 13 stations across the whole lagoon. The study was based on seasonal sampling over a one year period. A total of 2571 individuals representing 66 taxa belonging to 30 families and 10 orders were collected. Among these taxa 21 were molluscs, 19 were crustaceans, 10 were insects, polychaetes were represented by 14 taxa, one unidentified taxon and oligochaetes. The most diversified groups (molluscs and crustaceans) represented 60.59 % of the taxonomic richness. Benthic macroinvertebrates community composition was different not only between stations but also presented interseasonal variations. Four distinct benthic assemblages were identified between which diversity indices and abundances were significantly different. Dissolved oxygen, mud and coarse sand were the environmental variables most influential in structuring benthic macroinvertebrates communities in the Ebrie lagoon.