Mercury transport and fate in the Gulf of Trieste (Northern Adriatic)—a two-dimensional modelling approach

The Gulf of Trieste is subject to mercury pollution from the So a River which drains polluted sediments from the region of a former mercury mine in Idrija, Slovenia. This has resulted in elevated mercury levels in some marine organisms. Due to a concern for human health, a study has been undertaken to predict mercury contamination trends through the use of a field program and a mathematical model. An annual mercury mass balance of the Gulf is presented first in the paper. This confirms the assumption of the importance of the particulate mercury loads and sedimentation in the mercury cycle. A two-dimensional (2D) advection-dispersion model for non-conservative pollutants which simulates mercury cycling in the Gulf, is then described. This model incorporates the results of a 2D steady-state, primarily wind-driven hydrodynamic model and a 2D sediment transport model. A coupling of the submodels and verification of the integral mercury cycling model are also presented.