COTS Removal

We have started removals again this year and hope to lessen the numbers of these predator starfish on our coral reefs. The main removal methods here in the Mamanuca region are physical removal with metal rods and then burial ashore or drying out in the sun. We go to various sites with the help of volunteers and resort staff for removals and then identify the extent of infestation before deciding to list the site as a control site. Our aims are to assist resorts to maintain a CPUE (catch per unit effort) of 0.1 for control sites before moving to new cites. The CPUE gives an indication of the population of COTS in the controlled area. Scientists have estimated that a healthy coral reef (40%-50%coral cover) can support approximately 20-30 COTS per hectare (100m2). In CPUE terms, a CPUE of 0.1 is supposed to be the level at which coral growth will ‘keep up with’ the rate of COTS feeding – thereby leading to a sustainable situation (Aiello, 2003).