Global distribution pattern and conservation of the cosmopolitan cold-water coral species Desmophyllum dianthus under climate change

Global climate change impacts marine ecosystems differently across oceanic regions and depths. Thus, understanding how widespread key species adapt globally and locally to multidimensional climate change is crucial for targeted conservation. This study focuses on the cosmopolitan cold-water coral (CWC) Desmophyllum dianthus using ecological niche models (ENMs) to explore climate adaptation and conservation strategies. The findings indicated that D. dianthus occupied a broad ecological niche but had low ecological niche overlap across populations, suggesting local adaptations and supporting population-level ENMs. The models predicted that over 80% of D. dianthus suitable habitats would persist under SSP1-2.6 and SSP5-8.5 climate scenarios by the 2100s, potentially increasing to 95% as new habitats emerge, demonstrating its robust adaptability. However, localized environmental shifts could precipitate habitat losses in areas like the Reykjanes Ridge, Rockall Plateau, Mediterranean Sea, and Patagonian Shelf. We also applied Linkage Mapper to identify potential ecological corridors that intertwined nearshore macrohabitat patches with deep-sea stepping-stone habitats such as escarpments, seamounts, and ridges, maintaining population connectivity. Despite this, the habitats and ecological corridors of D. dianthus remained largely unprotected, with vulnerable portions lying outside of marine protected areas (MPAs), thus underscoring the urgent need for more MPA. These spatial-temporal predictions provide essential insights for the conservation and management of cosmopolitan CWC D. dianthus and serve as a benchmark for the adaptive survival of similar taxa.