Mangroves as Climate Refugia for Coral Reefs: A Review of Ecological Mechanisms, Opportunities and Trade-offs Under Climate Change

Coral reefs face unprecedented threats from climate change, particularly ocean warming and acidification. Mangrove-coral interfaces have emerged as critical climate refugia that buffer corals from thermal stress through multiple ecological mechanisms. This review synthesizes current knowledge on how mangrove ecosystems function as refugia through light reduction, temperature modulation, pH buffering, and oxygen dynamics. Additionally, mangrove-reef connectivity supports ecosystem services including fisheries productivity, coastal protection, and biodiversity conservation through ontogenetic habitat connectivity and nutrient provisioning. However, mangrove refugia operate within bounded spatial and temporal domains, with significant metabolic trade-offs including reduced calcification and reproductive rates in refuge associated corals. Accelerating mangrove degradation and climate change threaten refugial efficacy, with model projections indicating refugia lose protective capacity when global warming exceeds 3°C. Mangrove protection and restoration are essential but insufficient components of comprehensive climate adaptation strategies. Future coral reef persistence requires simultaneous progress in emissions reductions, mangrove-reef ecosystem protection, mitigation of non-climatic stressors, and deployment of emerging adaptation technologies.