RESUMEN
Aim: Benthic organisms in marine sediments affect several processes in which seas and oceans are very important. These organisms can represent the biodiversity, alive composition, biomass and prolificacy of the associated biota. The aim of this study was to determine the environmental effects of offshore aquaculture systems based on macrobenthic mollusc composition and the structure of its community in Ildır Bay during specific spatial and temporal patterns. Methodology: The benthic samplings of the zoobenthic organisms in the region were performed by means of Van Veen grab (10 l) from the sea sediment. In the laboratory, macrobenthic organisms were separated into main taxonomic groups. Various statistical methods were applied to establish the distributional and ecological characteristics of molluscan species and individuals. Results: The results of the present study indicated 44 species and 1287 individuals belonging to 33 families of Mollusca. T. distorta and C. gibba, which are particularly indicative of pollution, were found uncommon in the study area and stations. T. communis was found to be the most dominant (45%). With regard to mollusca species, in particular the fish farm was found to have no discernible negative effect at the sampling sites. Interpretation: Live fauna that were found inside and above the sediments at the sea bottom can be used as a decisive factor in fishery and aquaculture activities.