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

Abstract

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.

Marine debris: A proximate threat to marine sustainability in Bootless Bay, Papua New Guinea

“…Local fisheries resources are overexploited (Cinner and McClanahan, 2006), and there have been recent reports of outbreaks of crown-of-thorns starfish (Pratchett et al, 2009), as well as prolonged episodes of coral bleaching (pers. obs.…”

Recolonisation of Acropora hyacinthus following climate-induced coral bleaching on the Great Barrier Reef

“…However, A. hyacinthus is highly susceptible to coral bleaching (e.g. McClanahan et al 2004) as well as to hydrodynamic disturbance (Madin & Connolly 2006) and outbreaks of Acanthaster planci (Pratchett et al 2009). A. hyacinthus also tends to dominate shallow, exposed reef habitats in the western Pacific, and exerts a major influence on community structure and dynamics there.…”

Species and size diversity in protective services offered by coral guard crabs

“…Acanthaster is capable of consuming all reef corals, but does exhibit feeding preferences (Pratchett 2007;Pratchett et al 2009). Culcita is a generalist predator of sessile organisms, including corals (Glynn and Krupp 1986).…”