Novel mechanism of coral recovery to heat stress

Coral survival through increasingly frequent and severe heat stress events is a critical factor governing the persistence of reef ecosystems under climate change. However, prospects for survival through prolonged events have seemed bleak: recovery from bleaching has only been documented after temperatures returned to normal, and evidence that local management measures increase coral resistance is equivocal. Strikingly, we found corals that recovered from globally unprecedented thermal stress, experienced during the 2015 2016 El Niño, while still at elevated temperatures. Only corals protected from local stressors exhibited this capacity. Protected corals had distinct pre-bleaching algal symbiont communities, endured bleaching, and then recovered through proliferation of different symbionts. By illuminating connections between local protection and climate change resilience, these findings reveal unanticipated potential for coral survival in the Anthropocene.