Abstract:  Research into environmental sensitivities of coral reef fishes is often justified by the need to understand climate impacts on tropical fisheries production, yet much of this research is done to date is on very small, site attached fishes (e.g., Acanthochromis polyacanthus). To redress this, a team of researchers (led by Professors Morgan Pratchett and Philip Munday at the ARC Centre of Excellence for Coral Reef Studies) have embarked on an ambitious study to examine comprehensive effects of climate change on coral trout. Coral trout (mainly, Plectropomus leopardus) are the current mainstay of both commercial and recreational fisheries on Australia’s Great Barrier Reef, and are also among the most important fisheries target species on coral reefs throughout the Indo-Pacific. This research has revealed that coral trout are extremely sensitive to increases in seawater temperature, ocean acidification, as well as projected degradation of coral reef habitats due to climate change. Most notably, fertilised embryos of Plectropomus leopardus all died when exposed to temperatures >32 degrees, which is just 2.5 degrees above the normal ambient temperature at which these fishes spawn. Adult fishes exposed to elevated temperatures also exhibited marked declines in their physiological condition. Climate change is likely to undermine the sustainability of coral trout fisheries, though further work is needed to test the extent to which behavioural acclimation could moderate exposure of large-bodied and mobile fishes to ocean warming.

Biography: Professor Morgan Pratchett is a research fellow and chief investigator within the ARC Centre of Excellence for Coral Reef Studies, based at James Cook University. His research spans a broad range of topics, but is fundamentally focussed on providing scientific data to underpin improved management and conservation of coral reefs in Australia, and throughout the world.