ASSESSMENT OF THE IMPACT OF CHEMICAL-POLLUTANTS ON MUSSEL, MYTILUS-GALLOPROVINCIALIS, FROM THE VENICE LAGOON, ITALY

The purpose of this study was to identify possible relationships betwe en biochemical-Catalase, Superoxide dismutase (SOD: and Propionaldehyd e dehydrogenase (PDH)-and histochemical-Neutral Red Retention time (NR R)-parameters of mussels (Mytilus galloprovincialis) and chemical (Hg, Pb, Cd, Zn, Cr, DDTs and PCBs) contaminants front the most polluted a rea of the Venice Lagoon which lies around Porto Marghera (industrial pollution) and the city of Venice (domestic pollution). Sampling of mu ssels was undertaken at the beginning of March 1995 and repeated in Ma rch 1996, just before spawning, when tissue concentrations of chemical pollutants reach their annual maxima. The results of the organic cont aminant analysis showed generally good agreement between sites for the two sampling periods, with values broadly 10% lower during 1996 as co mpared to 1995. Metal contaminant concentrations in tissues revealed g reater variability than organic compounds. Distribution pattern of bio logical parameters were more complex and variable. The apparent lack o f significant positive correlations between antioxidant enzyme activit ies and pollutant body burdens as well as the low values of NRR are co nsistent with the present debate on the use of these biological indice s as markers of contaminant-mediated stress for molluscs. (C) 1998 Els evier Science Ltd. All rights reserved.