Seasonal dynamics of soft bottom zoobenthic communities in polluted and unpolluted areas of Izmir Bay (Aegean Sea)

The polluted and unpolluted parts of Izmir Bay (Aegean Sea) were sampled seasonally in 1995 and 1996 in order to delineate effects of pollution on the spatial-temporal distributions of soft bottom benthic animals. A total of 298 species, represented by 6014 individuals, belonging to 10 major groups were determined, of which Polychaetes accounted for almost 51% of the total number of species (153 species) and 82% of the total number of individuals (4942 specimens). Crustaceans and molluscs were next dominant after the Polychaeta. By utilising the result of the cluster analysis, four main species assemblages were recognised in the area, each containing different dominant species. The heavily polluted inner bay, which was mainly dominated by the opportunistic polychaetes, Capitella capitata, Polydora spp. and Ophiodromus pallidus, reached azoic conditions in summer and autumn. As the results of the present study compare with those of previous studies held in the bay, it can be concluded that pollution in the bay tends to increase and adversely affects distributions of zoobenthic animals particularly in the inner part of Izmir Bay.