Biomarkers in zebra mussels (Dreissena polymorpha) for the assessment and monitoring of water quality of the St Lawrence River (Canada)

Five biomarkers (MT. metallothionein-like proteins, EROD: ethoxyresorufin o rtho-deethylase, DNA strand breaks, LPO: poroxidation of lipids, VG: vitell ogenin-like protiens) were measured in the soft tissues of zebra mussels (D reissena polymorpha) in order to assess the spatial variation of exposure t o contaminants along the St Lawrence River (Canada). Fifteen mussels >25 mm shell length were analyzed from each of the 13 sampling sites. Significant differences between sites were noted for all biomarkers, but the general l evel of variability was low. Three biomarkers (DNA, LPO and VG) exhibited a similar pattern of spatial variation while MT and EROD had distinct and sp ecific patterns. MT had the strongest discriminating power and EROD showed the largest range of variation among sites. highest biomarker responses wer e measured in specimens from local contaminated sites such as harbors and i ndustrial sectors. A positive relationship was found between MT and copper (Cu), bur no significant correlation was observed between other. biomarker responses and the levels of ten trace metals bioaccumulating in the zebra m ussels tissues. Results indicate that the measurement of biomarker response s is technically feasible. The performance of each biomarker is assessed in the context of the rule and advantages of selecting a battery of biomarker s for detecting contamination problems. The use of zebra mussels as a senti nel species for biomonitoring potential toxic effects in situ is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.