Selective coral mortality associated with outbreaks of Acanthaster planci L. in Bootless Bay, Papua New Guinea

• Published in: Marine environmental research 2009-05, Vol.67 (4), p.230-236
• Main Authors: Pratchett, M.S., Schenk, T.J., Baine, M., Syms, C., Baird, A.H.
• Format: Article
• Language: English
• Subjects: Acanthaster planci; Acropora; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Anthozoa - physiology; Biological and medical sciences; Body Size; Cnidaria. Ctenaria; Coral reefs; Crown-of-thorns; Disturbance; Ecosystem; Effects-population; Fundamental and applied biological sciences. Psychology; Invertebrates; Marine; Oceans and Seas; Papua New Guinea; Population Density; Predation; Scleractinian corals; Sea water ecosystems; Starfish - physiology; Survival Analysis; Synecology
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/j.marenvres.2009.03.001

Population outbreaks of crown-of-thorns sea star ( Acanthaster planci L.) remain one of the most significant biological disturbances on tropical coral reefs although the increasing attention given to other threats has greatly limited recent progress in understanding the cause and consequences of this phenomenon. In September 2005 dramatic increases in the abundance of A. planci were observed on reefs within Bootless Bay, Central Province, Papua New Guinea, where few crown-of-thorns have previously been reported. Densities of A. planci peaked at 162 sea stars per hectare and caused extensive coral mortality. This outbreak killed upwards of 55% of live corals, reducing overall coral cover from 42.4% in 2005 down to just 19.1% in March 2006. Declines in coral cover were largely driven by widespread mortality of Acropora spp. which dominated reef assemblages prior to the outbreak. The extensive depletion of Acropora spp. greatly altered the coral composition as well as the physical structure of reef habitats. In the absence of any other major disturbances these coral communities are likely to quickly recover, but this outbreak highlights the ongoing contribution of A. planci to degradation of coral reef environments.