Launch of a New Local Monitoring Program to Manage a Crown-of-Thorns Starfish Population

In recent years, outbreaks of the starfish crown-of-thorns (COT), Acanthaster planci, have become a major concern in the Indo-Pacific region. Targeted removal of COT is the strategy the most often used to manage outbreaks.... [ view full abstract ]

In recent years, outbreaks of the starfish crown-of-thorns (COT), Acanthaster planci, have become a major concern in the Indo-Pacific region. Targeted removal of COT is the strategy the most often used to manage outbreaks. However, to be effective, this strategy should rely on an understanding of the demographics and dynamics of local populations. In order to gain such knowledge, a new local monitoring program, named TRACCOT, has been launched in February 2018 around the island of PomPom, just 30 km east off the coast of Semporna, Borneo, Malaysia. Underwater belt transects (2 m x 50 m), photoquadrats (50 cm x 50 cm), and depth are recorded monthly at five locations around the island (Lobster Wall, Eastern Plateau, Big PomPom, North Tip and North Tip buoy 1) to estimate population density and coral cover. Five additional sites in nearby islands (Kalapuan, Timba timba, and Mataking) are also part of the monitoring program to investigate population dynamics. Since inception, the program has been able to ascertain active outbreaks at 5 locations with more than 45 mature COT per hectare of reef (n=51). Interestingly, the site the most infested (Eastern Plateau, 182 COT.ha^-1) is not located directly downstream of Kapikan island, considered the source of COT larvae for PomPom Island. The data collected with TRACCOT will enable the development of a strategic management program and the efficient allocation of resources to reduce the population of A. planci along the coast of PomPom Island. It will also provide valuable management information for neighboring islands.