Global Potential Refugia and Conservation Gaps for Threatened Marine Rays Under Future Climate Change

Climate change is redistributing marine biodiversity and may reduce the long-term effectiveness of static conservation networks. Threatened marine rays may be particularly vulnerable because many species have slow life histories, limited recovery capacity, and strong dependence on coastal and shelf habitats. However, the global distribution of habitats expected to remain suitable for threatened rays under severe future climate change, as well as their representation within existing marine protected areas, remain poorly understood. Here, we projected ensemble species distribution models for 85 threatened marine ray species for 2090-2100 under SSP5-8.5 and quantified habitat loss, persistence, gain, and net-richness change. Climate-resilient hotspots were identified from stable suitable-habitat richness and intersected with multi-source conservation-priority areas to delineate potential climate refugia. Habitat losses and negative net-richness changes were concentrated mainly in tropical and subtropical coastal waters, whereas gains were more extensive at higher latitudes. The Top 10% and Top 5% stable hotspots covered 6.47 and 3.89 million km², respectively, yielding 1.64 million km² of potential refugia and 1.06 million km² of core refugia. Only 26.1-27.2% overlapped with existing marine protected areas, leaving 72.8-73.9% unprotected. These findings emphasize the need for climate-informed conservation planning, as most identified potential refugia remain outside the existing MPA network.