A 30-YEAR STUDY OF SEAGRASS BED FISH FAUNA SUBMITTED TO DIFFERENT WASTEWATER TREATMENTS (MARSEILLE, NW MEDITTEREAN)

The fish fauna of a Posidonia oceanica seagrass bed influenced by the Marseille sewage outfall was studied in summer and winter between 1980 and 2012, i.e. before and after improvements to the treatment of wastewater. A decrease in species richness, abundance and biomass was observed in summer, but not in winter. A modification of the trophic structure of the fish community also occurred in summer, with a decrease of zooplanktivores and labrids, and an increase in the relative importance of macrocarnivores