PARENT SESSION
5B The use of biomarkers for assessing ecosystem damage
9:00 AM to 7:00 PM, Wednesday, 09 May 2001

(W/EH121) The use of biomarkers in assessing the impact of harbour sediments discharged into coastal environments.

Regoli, Francesco¹, Gorbi, Stefania¹, Giuliani, Silvia², Lamberti, Claudia², Pellegrini, David², ^{1 2}

ABSTRACT- In the period 1997-2000, approximately 1.800.000 m³ of material dredged from the Port of Leghorn were discharged into the sea at 14 miles from the coast. The red mullet (Mullus barbatus) was used as bioindicator species and several biomarkers, both of exposure and effect, were analyzed for monitoring the biological impact on a geographical and temporal scale. Bioavailability of specific classes of pollutants was evaluated by analyzing the levels of metallothioneins and the activity of cytochrome P-450 (EROD), NADPH cytochrome C reductase and glutathione S-transferases. Among biomarkers of effect, special attention was paid to the balance between prooxidant forces and antioxidant defenses and to the appearance of oxidative stress conditions. The analyses of the main components of antioxidant system included superoxide dismutase, catalase, glutathione peroxidases, glutathione reductase, glyoxalase I and II, total glutathione. These data were integrated with the measurement of Total Oxyradical Scavenging Capacity (TOSC) indicating the overall biological resistance toward toxicity of different forms of oxyradicals (peroxyl radicals, hydroxyl radicals and peroxynitrite). The obtained results indicated a biological impact in organisms sampled near the discharge area; the impact was particularly evident during 1998 and mainly related to organic chemicals such as PAH. Exposure to these pollutants also caused variations in the levels and activity of several antioxidants; however, the analysis of TOSC, revealed a still active counteracting capacity in the organisms challenged with increased prooxidant pressures. The analysis of biomarkers in the red mullet appears an useful approach for monitoring the biological impact caused by dredged materials.

Key words: biomarkers, pollution, ecotoxicology, harbour materials