CoTS Control


Mitigating the impact of a current outbreak of COTS in the Beqa Lagoon area; providing the tools for long-term adaptive management allowing future control of COTS populations.


Villagers quantifying and measuring the collected CoTS

Crown-of-thorns starfish (COTS) are marine invertebrates reaching up to 80 cm in diameter, they feed primarily on hard corals. They occur naturally on reefs throughout the Indo-Pacific region. The continuing overexploitation of their natural predators which include the giant triton snail, the titan triggerfish and the humphead Maori wrasse alongside eutrophication of otherwise nutrient-poor tropical waters, create favourable conditions for COTS’ survival, and leads to population outbreaks. The widespread impact of COTS has been increasing in recent decades becoming one of the leading causes of coral cover losses in South Pacific coral reefs.

Efforts are focused on the manual removal of the CoTS by task forces composed of local community members, informed as to the impact of the CoTS on the reefs, and trained in locating & dealing with them. A  main emphasis is mitigating the potential of future outbreaks  through strategies based on educational, awareness and management programs to counter the impact of overexploitation of the CoTS natural predators, watershed management, and methods of reducing the outflow of nutrients to the reef from pig farms adjacent to beaches.