Evaluation of Sublethal Effects of Pollutants with Biochemical Indicators

Assessment of the quality of a marine environment requires precise and reliable indicators of the persistence of a pollutant or the recovery of a population from a pollution stress. We report in this study that biochemical indicators can detect of sublethal effects of pollutants in marine organisms. Blue mussels (Mytilus edulis L.) sampled on a rocky substrate at Pointe Mitis (Que.) were exposed to two sublethal concentrations of methylmercury (0.3 and 3.0 ug L^-1) for 29 days. Malate dehydrogenase and pyruvate kinase activities were significantly reduced with both concentrations of pollutants from day 22 of the experiment and no antagonistic effect of selenium was observed with either treatment. These results show that biochemical indicators (Km, Vmax) can precisely detect the appearance of sublethal effects of a pollutant, providing valuable informations about the level of pollution and the quality of the marine environment.