Lessepsian fish invasion in Mediterranean marine protected areas: A risk assessment under climate change scenarios

Mediterranean marine protected areas (MPAs), designed to achieve long-term nature conservation, are progressively conquered by invasive species of tropical origin, posing novel challenges for managers and policymakers of the 21st century. In this study, we assessed the vulnerability of 142 coastal Mediterranean MPAs to nine of the most invasive fishes under current and future climatic conditions. We predicted invasive species' habitat suitability using an ensemble modelling approach, calibrating models on the entire distribution of the species. We categorized three risk levels for Mediterranean MPAs, based on the assumption that more suitable habitat conditions make protected areas more prone to invasion. Future projections forecasted an increase of suitable areas for all considered species in the Mediterranean basin. In the Levantine Sea, almost all MPAs are at high risk of invasion by the considered species both in the current and future scenarios. MPAs located in the other Mediterranean sectors have currently a low suitability for most invasive species, but their risk level will increase overall by 2050, especially in the South Adriatic Sea and off South Western Italy. By identifying spatial priorities in a global change context, we fill critical information gaps on the vulnerability of MPAs to the future expansion of warm-water invaders.