Modelling mercury dynamics in the food web of the Augusta Bay

Mercury (Hg) contamination represents a significant environmental and public health challenge, particularly in heavily industrialized marine areas. The Augusta Bay, one of the most polluted marine ecosystems in Southern Italy, exemplifies the urgent need for integrated approaches to understand and mitigate Hg impacts. This study is the first to apply a multi-scale modelling framework to address Hg contamination in this region. By integrating environmental processes, food web dynamics and human health impacts, our analysis provides a comprehensive knowledge of Hg pathways and region-specific risks. The framework combines three advanced models. The HR3DHG model reproduces the transport and transformation of Hg species in seawater and sediments, with outputs validated through experimental data collected during extensive field campaigns. The HR3DHG model outputs are then used as inputs for the INTFISH model, which accurately reproduces Hg concentrations in marine organisms of the Augusta Bay while accounting for feeding habits and ecological interactions. Finally, the BBD model addresses the human health dimension by simulating the internal dynamics of methylmercury and its inorganic metabolites in the human body under chronic exposure scenarios. The experimental data coming from the Augusta Bay and their comparison with the values measured in the Hyogo Prefecture (Japan) allowed us to confirm the robustness and relevance of our results (model validation). This innovative framework devised for the Augusta Bay, offers a powerful tool for assessing ecosystem and human health risks associated with Hg contamination, and supports interventions targeted to mitigate the impacts of Hg pollution in coastal areas.