Cage Exposure of European Sea Bass (Dicentrarchus Labrax) for in Situ Assessment of Pollution-Related GenotoxicityGenotoxic effects are often the earliest signs of pollution-related environmental disturbance. In this study, we used the comet assay and micronucleus test to assess DNA damage in the erythrocytes of the European sea bass (Dicentrarchus labrax) exposed to environmental pollution in situ. Fish were collected from a fish farm in the Trogir Bay and their cages placed at an unpolluted reference site Šolta (Nečujam Bay) and a polluted site Vranjic (Kaštela Bay) for four weeks. A group of fish which remained at the fish farm Trogir Bay were used as the second control group. Fish exposed at the Vranjic site showed a significantly higher erythrocyte DNA damage, measured by the comet assay, than either control group. Micronucleus induction showed a similar gradient of DNA damage, but did not reach statistical significance. Our results show that cage exposure of a marine fish D. labrax can be useful in environmental biomonitoring and confirm the comet assay as a suitable tool for detecting pollution-related genotoxicity.