Abstract: In this seminar, I outline new biological insight into why poor water quality, particularly an excess availability of bioavailable nutrients, is an increasingly identified feature at reef locations that have low resistance to thermal stress. I demonstrate the predictive benefits of this new system-level understanding for: (i) improving early-warning forecasts of summer bleaching risk, (ii) explaining historical bleaching patterns, (iii) testing the bleaching-resistant quality of the current marine protected area (MPA) network, and (iv) targeting region-specific water quality improvement strategies that may enhance bleaching resistance. Moreover, I explain how the reef-scale attribute of bleaching resistance correlates strongly with routinely monitored coral health attributes, such as the tissue energy reserves and skeletal growth characteristics (viz. density and extension rates) of massive Porites spp. corals and the disease risk in branching Acropora spp. The result confirms that bleaching resistant (versus bleaching sensitive) reefs are readily identifiable and explainable by characteristic coral health signatures that exist outside of thermal stress conditions. Such information is of considerable value to local reef managers in their efforts to ‘field-rank’ bleaching-resistant reef areas for enhanced protection, and/or monitor the benefit of water quality improvement strategies that seek to increase reef-scale coral health and bleaching resistance.

Bio: Dr Scott Wooldridge is an ecological modeller who has spent the last 15 years working at the Australian Institute of Marine Science investigating the cumulative impacts of multiple stressors on coral reef and seagrass ecosystems. His research has pioneered the integration of novel Bayesian inference techniques and GIS to assist in various risk assessment and decision support projects on the Great Barrier Reef (GBR). In particular, his research has highlighted the importance of regional water quality as a fundamental driver of observed differences in reef health on the GBR, especially in relation the resisting the impact of thermal sea temperature anomalies. Scott has recently taken up an adjunct research position at the Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University where he is currently: (i) investigating the importance of enhanced larval survival and strong ‘local’ reef interconnectedness as a triggering agent for primary outbreaks of crown‐of‐thorns starfish on the central GBR, and (ii) assessing potential improvements in the health of coastal seagrass and dependent dugong populations due to targeted reductions in fine sediment loads from the GBR catchment.