Blue Crab Invasion and Sustainability of Maritime Trade: Ecological and Socio-Economic Adaptation in Mediterranean Sea in the Context of Climate Change

Abstract The BLEU-ADAPT project, carried out within the framework of the Interreg Italy-Tunisia cross border cooperation programme, investigates the marine biological invasion of two blue crab species (Callinectes sapidus and Portunus segnis) in the Mediterranean Sea, focusing on their ecological impact and socio-economic consequences for coastal fisheries. Framed within the broader environment and trade nexus, this research addresses the urgent need for adaptive and sustainable resource management in the context of climate-driven species migrations and changing marine trade dynamics. The project's theoretical approach is grounded in social-ecological systems theory and resilience thinking, integrating ecological forecasting with participatory governance models. It employs a multidisciplinary methodology that combines environmental field surveys, laboratory-based trait analysis, and socio-economic impact assessments conducted in Tunisia and Italy The research reveals significant ecological disruption and economic damage caused by the invasive blue crab, particularly to small-scale artisanal fisheries. These include destruction of fishing gear, reduced catch quality and increased operating costs. Predictive modelling based on functional traits indicates a likely expansion of C. sapidus throughout the Mediterranean over the next 30 years, while P. segnis is expected to remain restricted to the eastern basin. The contribution of this research is to develop science-based, participatory management strategies that link environmental adaptation with trade sustainability. By identifying high-risk zones and egg production areas, BLEU-ADAPT supports the design of regionally coordinated mitigation efforts and the potential valorization of invasive biomass through sustainable trade channels. The study contributes to rethinking international cooperation on marine invasions, trade policy and climate adaptation, in line with the broader goals of environmental justice and blue economy development in the Mediterranean. This presentation will reflect on how trade and environmental governance intersect in real-world coastal contexts, and how cross-border scientific collaboration can inform inclusive and resilient responses to ecological disturbances.