The fouling community as an indicator of fish farming impact in Mediterranean

Fouling species richness, abundance and composition and biomass were chosen as the descriptors of e¡ect of fish farm organic enrichment. The study was carried out in September 2004 inthe Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less signi¢cantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a filter naturally opposed by environment resistance assimilating and facilitating the accommodation of most organic surplus. In highly hydrodynamic and suffciently deep systems, the transport of organic particles produced from farms would have an eject along the horizontal axis rather than along the vertical axis, involving upper located benthic organisms rather than sedimentary benthic organisms.