A modeling study on methylmercury bioaccumulation and its controlling factors

The objectives of this study were: (1) to develop a methylmercury (MeHg) bioaccumulation model using data from STORM (high bottom Shear realistic water column Turbulence Resuspension Mesocosms) experiments; and (2) to use the model as a diagnostic tool to examine an effect of sediment resuspension and other important factors on MeHg bioaccumulation. There were four mesocosm experiments (1-4) conducted both in summer and fall. Tidal resuspension (4 h on- and 2 h off-cycles) was simulated using the STORM facility at CBL, UMCES (Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science). The model results showed that changes in clam biomass had a great effect on phytoplankton and zooplankton biomass, and consequently MeHg accumulation. In addition, it appeared that sediment resuspension played a role in transferring the enhanced sediment MeHg into organisms inhabiting both water column and sediment.