Sporadic Disturbances in Fluctuating Coral Reef Environments: El Niño and Coral Reef Development in the Eastern Pacific

The disastrous effects of the intense 1982-83 El Nino-Southern Oscillation (ENSO) bring new insight into the long-term development of eastern Pacific coral reefs. The 1982-83 ENSO sea surface warming event caused extensive reef coral bleaching (loss of symbiotic zooxanthellae), resulting in up to 70-95% coral mortality on reefs in Costa Rica, Panama, Colombia and Ecuador. In the Galapagos Islands (Ecuador), most coral reefs experienced >95% coral mortality. Also, several coral species experienced extreme reductions in population size, and local and regional extinctions. The El Nino event spawned secondary disturbances, such as increased predation and bioerosion, that continue to impact reef-building corals. The death of Pocillopora colonies with their crustacean guards eliminated coral barriers now allowing the corallivore Acanthaster planci access to formerly protected coral prey