Effects of Benzo(a)pyrene on Seabass (Dicentrarchus labrax L.): Biomarkers, Growth and Behavior

ABSTRACT

The main purpose of this study was to investigate the effects of benzo(a)pyrene (BaP) on seabass (Dicentrarchus labrax) juveniles using parameters at different levels of biological organization. Liver antioxidant status, BaP biotransformation and accumulation, growth, and behavior were determined in juveniles after 28 d exposure to BaP (1–16 μ g/l). Liver ethoxyresorufin O-deethylase increased in seabass exposed to 1–8 μ g/l of BaP. Liver glutathione S-transferases and catalase activities were significantly increased at 4 and 8 μ g/l, but a slight decrease was observed at the highest concentrations tested. Bile BaP metabolites were significantly different from the control group at 1 and 16 μ g/l BaP. Liver BaP metabolites and lipid peroxidation significantly increased at 8 and 16 μ g/l BaP. These results suggest that BaP metabolites' accumulation induces oxidative damage in seabass liver. Body weight and length increase were significantly reduced in fish exposed to BaP, with LOECs of 16 and 4 μ g/l, respectively. Food intake and swimming velocity were significantly decreased after exposure to BaP, with LOEC values of 16 and 8 μ g/l, respectively. Results suggest that at concentrations of BaP equal or higher than 8 μ g/l, the detoxification capacity decreases, an accumulation of liver BaP metabolites occurs causing lipid peroxidation, affecting growth and swimming capability of fish.

Key words:

• seabass
• benzo(a)pyrene
• biomarkers
• growth
• swimming velocity
• food intake
• oxidative stress

ACKNOWLEDGMENTS

This study was funded by “Fundação para a Ciência e a Tecnologia” (FCT) of Portugal (POST-DOC grant to C. Gravato, POCTI/BPD/21070/2004) and by EU FEDER funds. The study was performed in the scope of FCT project WESSEA (PDTC/MAR/64074/2006).