Research activities center on coral community structure and function with emphasis on natural and anthropogenic disturbances to coral reefs. Major attention has been directed toward an analysis of the impacts of the 1982-83 El Niño warming event on eastern Pacific coral reefs. The severely affected coral reefs in the eastern Pacific region are being study with respect to (1) initial and long-term disturbance effects (predation, competition, symbiosis, bioerosion), (2) causes of coral bleaching and mortality, (3) coral community recovery, and (4) records of El Niño disturbances in the past, based on evidence from core drilling, sclerochronology, stable isotope and trace metal signals.