Responses of Coral Reefs to El Niñno-Southern Oscillation Sea-Warming Events

Abstract

Prior to Chesher's (1969) stunning prediction that the corallivorous sea star, Acanthaster planci, could spell the initial phases of extinction of reef-building corals in the Pacific Ocean, coral reefs were regarded as highly stable and resilient ecosystems in near equilibrium with their physical and biotic environmental controls (e.g., Odum and Odum 1955; Wells 1957; Margalef 1968). Widespread outbreaks of A. planci and resulting coral mortality over the Indo-Pacific region have caused considerable alarm, and although the causes of these outbreaks are still unknown, some workers link them to favorable conditions in the water column promoting larval survival followed by heavy settlement and high recruitment (Birkeland and Lucas 1990). The effects of this predator are still a significant management problem in many areas (Wilkinson 1990; Wilkinson and Macintyre 1992; DeVantier and Done, Chapter 4), but concerns about A. planci disturbances have been increasingly supplanted by concerns about other global-scale disturbances that are linked to significant coral reef decline, including the deterioration of water quality from runoff