Local conditions magnify coral loss after marine heatwaves

See allHide authors and affiliations

Science  28 May 2021:
Vol. 372, Issue 6545, pp. 977-980
DOI: 10.1126/science.abd9464

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Think globally, act locally

Climate change–driven elevations in temperature over the past few decades have caused repeated coral bleaching and subsequent death. The impact is so widespread that it has been suggested that only climate change reversal can save coral reefs globally. Donovan et al. looked at the interaction between local conditions and coral reef health and found that poor conditions magnify climate impacts (see the Perspective by Knowlton). Furthermore, reefs where human stressors such as overfishing or pollution were minimized fared better. Such results suggest that caring for reefs locally may help them to persist in our warming world.

Science, abd9464, this issue p. 977; see also abi7286, p. 908


Climate change threatens coral reefs by causing heat stress events that lead to widespread coral bleaching and mortality. Given the global nature of these mass coral mortality events, recent studies argue that mitigating climate change is the only path to conserve coral reefs. Using a global analysis of 223 sites, we show that local stressors act synergistically with climate change to kill corals. Local factors such as high abundance of macroalgae or urchins magnified coral loss in the year after bleaching. Notably, the combined effects of increasing heat stress and macroalgae intensified coral loss. Our results offer an optimistic premise that effective local management, alongside global efforts to mitigate climate change, can help coral reefs survive the Anthropocene.

View Full Text

Stay Connected to Science