title: Climate change disables coral bleaching protection on the Great Barrier Reef.
abstract: Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective mechanism is likely to be lost under near-future climate change scenarios. We show that 75% of past thermal stress events have been characterized by a temperature trajectory that subjects corals to a protective, sub-bleaching stress, before reaching temperatures that cause bleaching. Such conditions confer thermal tolerance, decreasing coral cell mortality and symbiont loss during bleaching by over 50%. We find that near-future increases in local temperature of as little as 0.5°C result in this protective mechanism being lost, which may increase the rate of degradation of the GBR.
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4810, Australia.
authors.forename: Tracy D
authors.initials: TD
authors.lastname: Ainsworth
authors.affiliation: Coral Reef Watch, U.S. National Oceanic and Atmospheric Administration (NOAA), College Park, MD 20740, USA. Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4811, Australia.
authors.forename: Scott F
authors.initials: SF
authors.lastname: Heron
authors.affiliation: Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, Brisbane 4072, Australia. Australian Research Council Centre of Excellence for Coral Reef Studies, University of Queensland, Brisbane 4072, Australia.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Ortiz
authors.affiliation: Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, Brisbane 4072, Australia. Australian Research Council Centre of Excellence for Coral Reef Studies, University of Queensland, Brisbane 4072, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Mumby
authors.affiliation: Department of Environmental Sciences, Macquarie University, Sydney 2109, Australia.
authors.forename: Alana
authors.initials: A
authors.lastname: Grech
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4810, Australia. The College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4810, Australia.
authors.forename: Daisie
authors.initials: D
authors.lastname: Ogawa
authors.affiliation: Coral Reef Watch, U.S. National Oceanic and Atmospheric Administration (NOAA), College Park, MD 20740, USA.
authors.forename: C Mark
authors.initials: CM
authors.lastname: Eakin
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4810, Australia. The College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4810, Australia.
authors.forename: William
authors.initials: W
authors.lastname: Leggat
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000166:cytology / Q000502:physiology*; D002452:Cell Count; D016923:Cell Death; D057231:Climate Change; D057894:Coral Reefs; D004141:Dinoflagellida / Q000166:cytology / Q000502:physiology; D018869:Heat-Shock Response; D006358:Hot Temperature; D010788:Photosynthesis; D010860:Pigments, Biological / Q000502:physiology*; D013559:Symbiosis
chemical_list: D010860:Pigments, Biological