Validation of inland water pollution assessment using biomarker responses in caged carp (Cyprinus carpio)

The feasibility of using caged carp to assess the environmental quality of inland waters was investigated with genetically identical carp of a cultured F1 hybrid fish line. The primary objective of the experiments was to develop a reliable and reproducible method to monitor the inland water pollution and to classify the environmental quality of freshwater sites. Both in the spring and in the autumn of 1998 carp were caged for 4 weeks at eight different freshwater sites with varying levels of pollution in and around the city of Amsterdam. The data were used to validate freshwater quality assessment using fish biomarker responses under standardised conditions. Specimens of the sediments and carp muscle tissue were analysed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Sediments were also analysed for polycyclic aromatic hydrocarbons (PAHs). Carp livers, bile and plasma were isolated in order to determine levels and activities of a suite of biochemical parameters: hepatic phase I enzymes (cyt P450, cyt b5, EROD, P450 RED); hepatic phase II enzymes and cofactors (UDPGT, GST, GSH, GSSG); hepatic antioxidant enzymes (SOD, CAT, GPOX, GRED); biliary PAH metabolites (OH-pyrene); plasma transaminases (AST, ALT); and plasma vitellogenin levels. Strong pollution-related biomarker responses were observed, especially for the hepatic phase I enzymes. A clear distinction was demonstrated when sites were characterised using discriminant analysis run on the suite of biomarkers, indicating that multivariate analysis on biomarker data-sets is a suitable method for classifying the environmental quality of inland waters.