EFFECTS OF THE AEGEAN SEA OIL-SPILL ON BIOTRANSFORMATION ENZYMES, OXIDATIVE STRESS AND DNA-ADDUCTS IN DIGESTIVE GLAND OF THE MUSSEL (MYTILUS-EDULIS L)

Possible molecular biomarkers of impact by organic pollution on mussel s were applied to samples from five sites along the Galician Coast, Sp ain, taken 6 months after the oil spill from the tanker ''Aegean Sea.' ' Whole body aliphatic hydrocarbon concentrations were similar at all sites, but specific chemical ratios (resolved/unresolved hydrocarbons; carbon preference index; pristane/phytane) indicated a predominance o f degraded petrogenic hydrocarbons nearer the oil spill. Levels of who le body polycyclic aromatic hydrocarbons (sum of 13 PAHs) increased st eadily towards the oil spill, and were paralleled by increases in dige stive gland levels of total cytochrome P-450, CYP1A-like protein and l ipid peroxidation (con. coeffs. with PAHs of 0.64-0.67). Differences w ere more marked in CYP1A-like protein than total cytochrome P450, indi cating induction of specific P450 isoenzyme(s). No differences between sites were seen for benzo[a]pyrene hydroxylase, glutathione S-transfe rase, superoxide dismutase and DT-diaphorase activities. Bulky, hydrop hobic DNA-adducts were detected in digestive gland of mussels from ind ustrial and urban sites, but not from the site nearest to the oil spil l which had the highest tissue levels of PAHs. Overall the results ind icate induction of cytochrome P450(s) and oxidative damage in mussel w ith oil exposure.