Biomarker responses in European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) from a highly populated Mediterranean coastal area: The Gulf of La Spezia

The aim of this study, conducted as collaboration between the Department of Environmental Sciences (Siena University) and ICRAM (Rome), was to validate an integrated methodology to evaluate the ecotoxicological hazard in the gulf of La Spezia (Ligurian sea), a Mediterranean coastal area with high anthropogenic impact. The methodology was based on the application of a set of biomarkers (etoxyresorufin-o-deethylase (EROD), porphyrins, PAH bile metabolites) and chemical analysis (organochlorines (OCs), polycyclic aromatic hydrocarbons (PAHs), heavy metals) on two teleostean species with high commercial interest: the European sea bass (Dicentrarchus labrax) and the gilthead sea bream (Sparus aurata). The coastline offshore the village of Lavagna, 50km west of La Spezia, was selected as reference site. Seasonal samplings were carried out; fish were obtained from sea-caged farms at both sites. Statistical analyses indicated the induction of CYP1A (EROD activity) and naphthalene metabolites in bile as the most sensitive biomarkers, showing a significant induction in La Spezia in comparison with the control site. No significant differences in porphyrin concentrations were found between the sites. PAHs and OCs levels in liver and muscle showed a general agreement with biomarker responses. In conclusion, the integrated use of biomarkers and chemical analysis in sea bass and sea bream can be considered a powerful tool in evaluating the impact of pollutants that can be applied within the framework of marine coastal environmental monitoring programs. This study was supported by La Spezia Port Autority with the supervision of ICRAM institute within the research program related to the monitoring activities for the remediation and dredging activities of La Spezia Harbour area.