Abstract: Outbreaks of the corallivorous Crown-of-thorns starfish (COTS; Acanthaster cf. solaris) have been responsible for 40% of the decline in coral cover on the GBR over the last 35 years. With the intensity and frequency of bleaching and cyclonic disturbances predicted to increase, effectively managing these outbreaks may give reefs an opportunity to partially recover from these cumulative impacts. Major limitations in contemporary control programs of COTS revolve around our understanding of the spatial and temporal patterns of COTS outbreaks. My research addresses these limitations by constructing a spatially explicit COTS-Coral metapopulation model for the GBR between 1996-2017, and building several key modelling tools en route towards this goal. Firstly, I collated the disturbance history (1985-2017) and abiotic regime for the GBR at a 1x1km resolution as a standardized platform to develop regional scale models for the GBR. To synthesise the extensive and disparate streams of COTS observational data, I developed an interactive visualisation and analytical platform, The COTS Dashboard. This tool, currently being used by the Great Barrier Reef Marine Park Authority,  allows researchers and managers to assess the severity and extent of COTS outbreaks and monitor progress towards stated management goals. Using the data collated by the two previous tools I developed a habitat suitability model for COTS, which provides the firsts validated estimates of COTS outbreak probability across the GBR, identifying the importance of a variety of water quality, larval connectivity and abiotic variables in predicting COTS spatial distribution. Finally, the COTS-Coral metapopulation model recreates the trajectories of coral cover and COTS for the last 23 years accounting for major disturbances, water quality and larval connectivity variability. This model provides a framework within which future management scenarios for COTS outbreaks can be tested. Overall my research aims to provide modelling and data tools for researchers and management alike for the development of the most effective and efficient management of COTS outbreaks.

Biography: Originally from Sydney, Sam is an AIMS@JCU PhD candidate at the ARC CoE for Coral Reef Studies. Previously, Sam studied Marine Science at the University of Wollongong, with his honours thesis investigating the effects of climate change on social hierarchies in an invasive fish species. This experience inspired Sam to pursue a PhD at James Cook University. Under the supervision of Morgan Pratchett and Camille Mellin, his project focuses on developing modelling and visualisation platforms for understanding the temporal and spatial patterns of Crown-of-thorns starfish (COTS) outbreaks. Importantly his research aims to identify key drivers of COTS outbreaks while also focusing on improving management of the pest species.