Local management of coral reefs to ease environmental stressors, such as overfishing or pollution, could increase reefs' chances of recovery after devastating coral bleaching events caused by climate change, a new study finds. The results suggest that caring for reefs on a local scale might help them persist globally. When waters warm, corals can die quickly and en masse in coral bleaching events. Marine warming due to climate change has resulted in sharp increases in both the frequency and magnitude of these mass mortality events, which have already caused severe damage to reefs worldwide. Because of the global nature of coral bleaching, many studies argue that mitigating climate change is the only way to ensure the survival of these sensitive ecosystems. Occasionally, however, surviving corals rebound after bleaching events, and reefs recover. It's unknown whether local reef management strategies play a role in this resilience. Mary Donovan and colleagues evaluated data from 223 coral reefs from across the Caribbean and Indo-Pacific and found that coral loss one year after bleaching was highly correlated to aspects of reef health - specifically the abundance of sea urchins and macroalgae, which are indicators of overfishing and pollution. According to the findings, locally managed reefs, where human stressors were minimized, fared better than non-managed reefs. While the mechanisms underpinning this resilience remain to be discovered, Donovan et al. argue that, in addition to efforts to reduce global carbon emissions, local management is crucial to helping coral reefs to survive the Anthropocene. "During upcoming global negotiations, governments should remember that in addition to setting ambitious targets for lowering greenhouse gas emissions, empowering local communities to manage reef and other marine resources is an important strategy to reduce the negative impacts of climate change," writes Nancy Knowlton in a related Perspective.
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Journal
Science