Assessing the risk of oil spill impacts and potential biodiversity loss for coastal marine environment at the turn of the COVID-19 pandemic event

The Tuscan Archipelago, with its great environmental and economic importance, is one of the highest oil spill density areas in the Western Mediterranean. In this study, an interdisciplinary approach, based on numerical applications and experimental methods, was implemented to quantify the risk of oil spill impact along the rocky shores of this archipelago in relation to the maritime activities. The risk, defined as a combination of the hazard and the damage, was quantified for the biennial 2019-2020 in order to account for the effects generated by the COVID-19 pandemic restrictions on the local maritime traffic. A high-resolution oceanographic and particle tracking model was applied to simulate the trajectories of possible oil spill events and to quantify the hazard of impacts on the coast of numerical particles, daily seeded in correspondence of those marine sectors that are characterised by relevant traffic of vessels. The damage, expressed as the product of exposure and vulnerability, was estimated following an extensive sampling approach aimed at quantifying the ecological status of the rocky shores in four selected islands of the Tuscan Archipelago. Results revealed and quantified the direct relationship between the temporary reduction of the maritime traffic due to the pandemic restrictions, and the probability of suffering damage from oil spill impact along the archipelago's rocky shores, which was highly context-dependent.