Population Explosions ofAcanthaster planciand Associated Destruction of the Hard-coral Cover of Reefs of the Great Barrier Reef, Australia

Abstract

Population explosions of the Crown-of-thorns Starfish,Acanthaster planci, first reported on reefs of the Great Barrier Reef in the Cairns region near lat. 17° S during the early 1960s, have since spread to numerous other reefs. The spread has been predominantly southwards, the principal region of infestation currently lying between lat. 19° S and lat. 19°20' S. South of this region, scattered infestations of reefs have recently been reported. Available data indicate that most reefs in the middle third of the Great Barrier Reef were infested during the last decade, and it is postulated that most reefs in the southernmost third will be infested during the next decade.The bulk of the hard-coral cover of most of the inner platform reefs infested, and a lower but significant percentage of the hard-coral cover of the outer platform reefs affected by the infestations, have been devastated. Recovery of devastated reefs is in progress but is slow.TheA. planciinfestations appear to the authors to be man-induced, and it is suggested that international action be taken to assess the magnitude of theA. planciproblem and to coordinate possible control activities in the Indo-West Pacific region.