• Energy Research

AbstractRapid anthropogenic climate change is driving threatened biodiversity one step closer to extinction. Effects on native biodiversity are determined by an interplay between species' exposure to climate change and their specific ecological and life‐history characteristics that render them even more susceptible. Impacts on biodiversity have already been reported, however, a systematic risk evaluation of threatened marine populations is lacking. Here, we employ a trait‐based approach to assess the risk of 90 threatened marine Mediterranean species to climate change, combining species' exposure to increased sea temperature and intrinsic vulnerability. One‐quarter of the threatened marine biodiversity of the Mediterranean Sea is predicted to be under elevated levels of climate risk, with various traits identified as key vulnerability traits. High‐risk taxa including sea turtles, marine mammals, Anthozoa and Chondrichthyes are highlighted. Climate risk, vulnerability and exposure hotspots are distributed along the Western Mediterranean, Alboran, Aegean, and Adriatic Seas. At each Mediterranean marine ecoregion, 21%–31% of their threatened species have high climate risk. All Mediterranean marine protected areas host threatened species with high risk to climate change, with 90% having a minimum of 4 up to 19 species of high climate risk, making the objective of a climate‐smart conservation strategy a crucial task for immediate planning and action. Our findings aspire to offer new insights for systematic, spatially strategic planning and prioritization of vulnerable marine life in the face of accelerating climate change.

As climate-related impacts threaten marine biodiversity globally, it is important to adjust conservation efforts to mitigate the effects of climate change. Translating scientific knowledge into practical management, however, is often complicated due to resource, economic and policy constraints, generating a knowledge-action gap. To develop potential solutions for marine turtle conservation, we explored the perceptions of key actors across 18 countries in the Mediterranean. These actors evaluated their perceived relative importance of 19 adaptation and mitigation measures that could safeguard marine turtles from climate change. Of importance, despite differences in expertise, experience and focal country, the perceptions of researchers and management practitioners largely converged with respect to prioritizing adaptation and mitigation measures. Climate change was considered to have the greatest impacts on offspring sex ratios and suitable nesting sites. The most viable adaptation/mitigation measures were considered to be reducing other pressures that act in parallel to climate change. Ecological effectiveness represented a key determinant for implementing proposed measures, followed by practical applicability, financial cost, and societal cost. This convergence in opinions across actors likely reflects long-standing initiatives in the Mediterranean region towards supporting knowledge exchange in marine turtle conservation. Our results provide important guidance on how to prioritize measures that incorporate climate change in decision-making processes related to the current and future management and protection of marine turtles at the ocean-basin scale, and could be used to guide decisions in other regions globally. Importantly, this study demonstrates a successful example of how interactive processes can be used to fill the knowledge-action gap between research and management.

Rising ocean temperature impacts the functionality and structure of ecosystems, further triggering the redistribution of biodiversity. Still, the magnitude and anticipated impacts of ocean warming are not expected to be uniform across marine space. Here, we developed a two-fold index-based approach to provide an integrated climatic vulnerability assessment of the marine surfaces which are enclosed within protected areas in the Mediterranean Sea. We first built a climatic stability index, based on metrics of analog-based velocity of climate change over a 120-year period (1950-2069), to assess patterns of climate dynamics within the marine protected surfaces. To provide a vulnerability ranking of protected surfaces under climate change, we combined this climate-related index with an index of community stability, reflecting the projected distribution shifts of 71 species of high conservation value. Our analyses revealed a highly heterogeneous and dynamic climatic space, with increasing but spatially inconsistent patterns of climate change velocities over successive 30-year periods. We found that about 62% of the protected marine surface might be subjected to low/very low climatic stability. About 70% of the protected waters were also found to be of limited community stability. Thus, protected surfaces across the Mediterranean basin were characterized by high vulnerability under changing climatic conditions, while only 5.7% of them exhibited high and very high stability based on both indices. Our findings suggest that combining information on climate change dynamics and biotic stability could offer spatially explicit insights which cannot be obtained based simply on the ecological dimensions of conservation planning.