The Aegean Sea oil spill on the Galician Coast (NW Spain). III:The assessment of long-term sublethal effects on mussels.

Several biomarkers of exposure to organic pollutants, namely the cytochrome P450 system, glutathione S-transferases, superoxide dismutase, DT-diaphorase and lipid peroxidation, were measured on mussels collected in five locations along the Galician Coast (NW Spain), 6, 9 and 12 months after the Aegean Sea oil spill. Among the studied biomarkers, a significant induction of the cytochrome P450 content and lipid peroxidation, determined as tissue concentration of malondialdehyde equivalents, was detected in mussels collected near the wreck point 6 months after the spillage. Thereafter, no significant differences between reference and polluted sites were detected. Nevertheless, the data suggest the existence of oxidative stress in mussel populations during the September-December samplings. A significant elevation of superoxide dismutase activity was detected in September-9 months after the accident-and this elevation was particularly evident in those stations located closest to the wreck point. Lipid peroxidation increased throughout the year and despite the existence of a strong seasonal effect, the whole data set was correlated with total PAH body burden (R= 0.56).