Abstract: Outbreaks of the coral eating crown-of-thorns starfish (CoTS), Acanthaster planci, have contributed greatly to sustained declines in live coral cover on the Great Barrier Reef (GBR), accounting for 42% of coral loss over the past 30 years. Unlike other disturbances (e.g., cyclones and coral bleaching), CoTS outbreaks may be amenable to direct management, especially if reef-wide outbreaks originate in small, well-defined areas. This study aims to reconstruct reef-wide outbreaks using extensive empirical data CoTS life history, distribution, hydrodynamic connectivity to help establish when, where and why outbreaks originate, how they spread and whether they can be stopped. We define habitat suitability for CoTS using an ensemble Species Distribution Modelling approach coupled with larval connectivity estimates across the GBR, allowing us to identify the probabilistic pathway of the southward propagation of CoTS outbreaks. These suitability and connectivity estimates are then combined with a stage-based demographic model of CoTS population growth to build a spatially explicit metapopulation model. This model will allow us to simulate the initiation and propagation of CoTS outbreaks under a range of management strategies. Our model will provide invaluable predictions for decision makers, identifying the key locations for control measures to help prevent the spread of future outbreaks. These predictions are an integral step towards reducing coral loss caused by CoTS outbreaks, and hence protecting live coral cover on the GBR.
Biography: Samuel is an AIMS@JCU PhD student working under Morgan Pratchett, Camille Mellin and Julian Caley on predicting outbreaks of Crown-of-thorns starfish. Originally from the University of Wollongong, Sam’s background is in fish behaviour. Currently, he is invested in the modelling world, especially in the ecological implications of connectivity networks and population dynamics.