BIOMARKERS OF MARINE POLLUTION OBSERVED IN SPECIES OF MULLET LIVING IN 2 EASTERN MEDITERRANEAN HARBORS

The activities of enzymes associated with xenobiotic metabolism and/or oxidative processes, and the levels of aromatic-DNA adducts, have bee n determined in the livers of grey mullet (Oedalechilus labeo and Lisa ramada) living in two eastern Mediterranean harbours. Glutathione per oxidase (GSH-P) activity was 2.5 times higher (similar to 9 IU g(-1) l iver) and glutathione reductase (GSSG-R) activity was twice as high (s imilar to 2.5 id g(-1) liver) in fish from the more polluted harbour a t Mersin than in the harbour near Erdemli. Superoxide dismutase (SOD) activity was 25% lower (4.3 IU g(-1) liver) in the more polluted harbo ur. The concentrations of glutathione and malondialdehyde varied both with species and environment by a factor of 2.5-3. DNA adducts in live r were determined by P-32-postlabelling. In Oedalechilus labeo in the more polluted harbour, adduct levels were 258 +/- 21 adducts per 10(8) nucleotides (mean +/- SE); two groups of Lisa ramada were distinguish ed having 261 +/- 48 and 30 +/- 6 adducts per 10(8) nucleotides, respe ctively. The average adduct level in a group of mullet of mixed specie s in the less polluted harbour was 3.3 +/- 2.3 adducts per 10(8) nucle otides. The results illuminate the ability of mullet to live in contam inated marine environments, and show that enzyme activities and liver DNA adduct levels can serve as indicators of marine pollution.