ABSTRACT
The starfish Acanthaster planci (L) is a common inhabitant of the indopacific coral reef ecosystem. Over the last 25-year period, Acanthaster infestations occuring in various coral reef areas have been studied and several hypotheses advanced to explain this phenomenon. The Acanthaster infestation has a snow-ball progression with increasing feedback effects which lead to the complete destruction of the coral communities. The coral polyps are preyed upon and algal communities grow upon dead coral colonies; this leads to major disruption of the trophic relationships in the coral reef ecosystem. Infestation disappears when coral food becomes insufficient and when the sessile photophilous assemblages (dominated by corals), characteristic of the coral reef ecosystem s.s., are replaced by algal substitution facies.
