Macrobenthic organisms were classified into five different feeding groups: detritivores (surface-deposit feeders, SDF; suspension feeders, SF; subsurfacedeposit feeders, SSDF), herbivores (He) and predators (PR), according to Bianchi & Morri (1985), Gambi & Giangrande (1985), Scipione (1989), Russo (1989), Russo et al. (1985), Gambi et al.