Multi-risk assessments in the context of adaptive marine management: the case study of the Adriatic sea

Marine areas represent complex and dynamic systems facing increasing threats and degradation due to multiple activities (e.g. fishing, sands and hydrocarbon extraction, tourism, energy infrastructures) taking place in the marine regions without the full understanding of the composite interactions between natural and human-induced changes. The cumulative and synergic impact among these activities and climate change is triggering severe alteration on biological, chemical and physical processes, with cascading effects on the socio-economic system. As a consequence marine managers and policy makers are increasingly calling for new approaches and tools able to account for changing conditions over time due to natural processes and different management options. Improving our capacity to model and evaluate the combined effects of multiple stressors (e.g. temperature and salinity variation, shipping traffic, aquaculture), in decisional contexts where data are limited and uncertainty is high, is therefore essential to address the future planning and management of our seas. In this setting, complex system methods (e.g. Bayesian belief network) are finding increasing application, as they represent flexible decision-support tools facilitating a rapid conceptualization of a system to be managed as well as the evaluation of the causal assertions between data and their inherent uncertainty as belief probabilities. By considering different climate scenarios and alternative management measures, a holistic multi-risk approach was developed to evaluate the cumulative impacts induced by climate and anthropogenic pressures on key marine targets (e.g. seagrasses, maërl and coral beds, marine protected areas). A first testing of the designed methodology, including the application of complex system methods to visualize and assess the impact of potential alternative scenarios, was applied in the Adriatic sea case study. The results of the assessment will allow the development of multi-risk scenarios able to support adaptive management accounting for uncertainties and unexpected scenarios within marine areas.