Global gaps and priorities for shark and ray conservation: Integrating threat, function, and evolutionary distinctiveness
Elasmobranchs (sharks, rays, and skates) face unprecedented extinction risk, with over one-third of species threatened primarily by overfishing. While marine protected areas (MPAs) are essential tools to help safeguard marine ecosystems and the species that inhabit them, we lack a comprehensive understanding of how well elasmobranchs are protected globally. Here, we (1) evaluate the current level of protection for elasmobranchs, (2) employ CAPTAIN reinforcement learning algorithm to identify areas that optimise conservation based on species level of threat and their functional and evolutionary distinctiveness, and (3) examine conservation conflicts and opportunities by identifying areas where conservation priorities overlap with high and low fishing pressures. Our analysis revealed severe protection deficits, with elasmobranchs having on average only 3% of their range covered by no-take MPAs and 64% of species under-represented relative to random expectations. Areas that optimise conservation priorities consistently converged in Australian, Southeast Asia, the Indian Ocean, Atlantic Africa, European Atlantic coasts, the Caribbean, and South American Atlantic regions. However, areas of highest conservation priority often coincided with intensive fishing, particularly in East Asian seas, highlighting conservation conflicts requiring strategic management. Our results provide actionable insights for policymakers to optimise conservation strategies and maximise biodiversity retention. TeaserReinforcement learning identifies priority areas to expand ocean protection for unique and irreplaceable elasmobranchs.