Author(s): D. Zagar; G. Petkovsek; R. Rajar; N. Sirnik; M. Horvat; M. Cetina
Keywords: Mathematical model; Hydrodynamic modelling; Mercury cycling; Mediterranean; Biogeochemistry
Abstract: Due to its toxicity and bioaccumulativity mercury represents potential danger for the whole food-web and humans at its end. In the Mediterranean elevated concentrations of mono- methyl mercury in fish tissue have been measured during the last decades. In this paper mathematical modelling in the aquatic environment of the Mediterranean region is presented. An existing 3D baroclinic hydrodynamic and transport dispersion model PCFLOW3D has been upgraded with a biogeochemical module in order to simulate mercury transport and transformation processes. The hydrodynamic circulation for the four main seasons has been calculated and compared to the measured values. The transport and dispersion of mercury has further been simulated with seasonally averaged velocity fields. As the established provisional mass balance of mercury showed that exchange with the atmosphere is the main source / sink of elemental mercury for the Mediterranean, the model has been further upgraded with a gas exchange module for elemental mercury between water and the atmosphere. The model is being linked with a meteorological model in order to improve the accuracy of the mercury cycling simulations.