The Crown of Thorns Startfish (COTS) Secretome: Towards a Control Technology

Crown-of-thorns starfish (COTS) are obligate corallivores and individual adults consuming between 6 – 10 m2 of live coral per year. Feeding aggregations of hundreds to many thousands of COTS can cause significant loss of coral cover on infested reefs. With the Great Barrier Reef (GBR) under a variety of pressures, with progressive loss of equilibrium, population explosions of COTS are increasingly making them a native pest requiring control measures. It is critical that tools and technology are available to implement, where and when needed, population control measures against this native pest. Control measures to control starfish populations have not advanced for over half a century and relies on manual collection or eradication of individuals one at a time. The most advanced and sophisticated technologies for pest control are those in agriculture. Many of these are not suitable for use to control pests in the marine environment. However, an effective and environmentally sensitive approach to control pests includes integrated pest management (IPM), also known as ‘Push-Pull Technology’, which is based upon the use of compounds which ‘push’ pests away from their intended target and simultaneously ‘pull’ them towards a trap or aggregation area for efficient removal. The technology depends on understanding and exploiting vulnerabilities in the chemical communication attributes of the pest species.
The activities are anticipated to contribute to achievement of the targets because they are directed to the demonstration that chemoreception is a major and driving force of COTS behavior. These attributes can be exploited as vulnerabilities in order to disperse or aggregate COTS improving the effectiveness, in labour and costs, in controlling populations of COTS.
The proposed activities will provide critical evidence to support the premise that chemoreception attributes of COTS can be exploited to develop a Push-Pull Management approach to control their populations. This may be achieved by:
_ Inducing alarm and dispersal of adult COTS to remove them from a vicinity and/or to make physical removal more cost effective.Inducing aggregation response of adults COTS to gather individuals to a point source where they may be controlled or removed from the environment. Disrupting the spawning capability of highly fecund adult COTS thereby eliminating reproductive success of breeding aggregations