Degraded Coral Reefs are Becoming More Resistant to Hurricanes

Abstract The frequency and intensity of Atlantic cyclonic storms are projected to increase as climate change warms the ocean 1,2. These changing disturbance dynamics, paired with simultaneous changes in the condition and composition of Caribbean coral reefs, could be altering reef resilience to storms in unexpected ways. For example, the observed decline of fast-growing, disturbance-sensitive species could promote resistance to and decrease recovery from storms3,4, increasingly locking reefs into a state dominated by weedy taxa. To test this hypothesis, we combined data from coral reef monitoring studies and historical hurricane records to develop a regional reef-storm interaction database. We found that as the living cover of Caribbean corals declined over the past 40 years, while resistance to storms increased, despite a concurrent increase in cyclonic storm frequency and intensity. Because storms selectively damaged branching coral species and had no measurable effect on the cover of “weedy” corals, reef composition shifted towards greater weedy dominance and reduced ecological function. Additionally, storms accelerated the loss rate of threatened acroporid corals, already in pre-storm decline, suggesting a worrisome synergism with other climate-related disturbances.