Assessment of coastal pollution by combined determination of chemical and biochemical markers in Mullus barbatus

Abstract

Muscle concentrations of organochlorinated compounds as well as biliary levels of polycyclic aromatic hydrocarbon (PAH) metabolites were determined in red mullet Mullus barbatus as a sentinel species for assessing the pollution along the western Mediterranean coast. A battery of biochemical markers - biotransformation and antioxidant enzymes - were also measured in liver subcellular fractions to assess exposure to pollutants. Among them, 7-ethoxyresorufin O-deethylase (EROD) activity, as well as 7-penthoxyresorufin O-deethylase (PROD) activity and cytochrome P450 1A (CYP1A) content evidenced strong differences among sampling sites, and a good correlation with the amount of PCBs bioaccumulated by fish. No clear pollution-related response was observed for cytosolic glutathione S-transferase, whereas uridine-diphosphate UDP-glucuronyltransferase (UDPGT) was elevated in fish from polluted sites. Antioxidant enzymes - superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) - were used to assess oxidative stress. Among them, catalase activity was well related to PCB body burden.