Modelling trace metal (Hg and Pb) bioaccumulation in the Mediterranean mussel, Mytilus galloprovincialis, applied to environmental monitoring

Bioaccumulation of metal within an organism results from interactions between physiological factors (growth, weight loss, absorption and accumulation), chemical factors (metal concentration, speciation and bioavailability) and environmental factors (temperature and food concentration). To account for such interactions in the mussel Mytilus galloprovincialis, we combined bioaccumulation and Dynamic Energy Budget models. Field experiments were conducted to measure uptake and elimination kinetics for two metals (Hg and Pb) in three Mediterranean sites with differences in contamination levels, and to calibrate the models. Metal uptake from water and from food was considered separately. Metal elimination resulted from reproduction and/or from direct excretion. Contributions of physiological variables, such as body size and tissue composition, were quantified. By combining environmental and biological data, the model provided an efficient bio-monitoring tool which can be applied to various coastal environments. An application to the French bio-integrator network (RINBIO) was carried out through inverse analysis and enabled us to assess the real level of contamination in water on the basis of contamination measured in mussels.