Coral reef ecosystems and marine heatwaves
Dr Rick Stuart-Smith1
1University of Tasmania, Hobart, Australia
Mass coral bleaching events are changing the makeup of entire ecological communities, but this is not just occurring through loss of live coral habitat. Extreme temperatures affect reef fauna in different ways in different locations, and these interact with habitat loss associated with coral bleaching – and numerous other pressures, including cyclones, fishing, sedimentation and crown of thorns sea star outbreaks. Our view of the impacts of the heatwaves that cause coral bleaching events has been restricted by the relatively narrow geographic scope of most previous studies, and generally poor consideration of the potential role that other pressures may play in shaping outcomes. Using the Reef Life Survey data on corals, algae, fishes and mobile invertebrates from 768 surveys spanning the entire length of the Great Barrier Reef and SW Coral Sea (14 degrees of latitude), the signals of ecosystem change from before to after the mass bleaching event of 2016 only partially related to local patterns in coral mortality. This talk will include results from two sets of analyses of these data that clearly demonstrated the importance of considering larger-scale outcomes of interacting pressures when interpreting patterns of local ecological change.
Biography:
Rick Stuart-Smith is a field ecologist and co-founder of the Reef Life Survey program (RLS). Since starting RLS in 2007, he has undertaken dive surveys of rocky and coral reefs all around the world and trained over 200 divers to assist in building an extraordinary quantitative database of reef biodiversity. His research covers aspects of biogeography, community and macro-ecology, focussing on the ways that climate change, fishing, pollution, invasive species and other environmental factors shape reef ecosystems. A major motivation for his research is to improve the way we monitor, share, manage and protect marine biodiversity, through contributing to more ecologically-informed policy at larger scales, and guiding local management. He also manages a global database of reef species and online field guide and contributes to building public knowledge of marine biodiversity values.