The scleractinian coral genus Acropora is a competitively dominant species in shallow coral reefs of the Indo-Pacific. It is highly susceptible to bleaching, which is thought to be primarily caused by a combination of increased water temperatures and other stresses. Warm-water anomalies have increased in severity over the past few decades, and Acrophora has subsequently lost its dominance over extensive areas. Warm-water anomalies are associated with periodic oceanographic oscillations overlain on rising seawater temperatures. Acropora and many other corals appear to be more resilient to water temperature changes when they occur in localities that have naturally fluctuating temperatures. Corals in such areas may be better acclimated to environmental variation and may serve as models for ways that corals can become resilient to climate change. This photograph originally appeared on the cover of Ecological Monographs (77:4) in November of 2007.