Coral record of southeast Indian Ocean marine heatwaves with intensified Western Pacific temperature gradient.
Increasing intensity of marine heatwaves has caused widespread mass coral bleaching events, threatening the integrity and functional diversity of coral reefs. Here we demonstrate the role of inter-ocean coupling in amplifying thermal stress on reefs in the poorly studied southeast Indian Ocean (SEIO), through a robust 215-year (1795-2010) geochemical coral proxy sea surface temperature (SST) record. We show that marine heatwaves affecting the SEIO are linked to the behaviour of the Western Pacific Warm Pool on decadal to centennial timescales, and are most pronounced when an anomalously strong zonal SST gradient between the western and central Pacific co-occurs with strong La Niña's. This SST gradient forces large-scale changes in heat flux that exacerbate SEIO heatwaves. Better understanding of the zonal SST gradient in the Western Pacific is expected to improve projections of the frequency of extreme SEIO heatwaves and their ecological impacts on the important coral reef ecosystems off Western Australia.
School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|UWA Oceans Institute, 39 Fairway, Nedlands, Western Australia 6009, Australia.|Australian Institute of Marine Science, PMB 3, Townsville MC, Queensland 4810, Australia.|Department Environment and Agriculture, Curtin University of Technology, Kent Street, Bentley, Western Australia 6102, Australia.|School of Geography, Archaeology &Environmental Studies, University of the Witwatersrand, Wits 2050, South Africa.
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J
Zinke
Department of Geography, University of California Santa Barbara, Santa Barbara, California 93106, USA.
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A
Hoell
Australian Institute of Marine Science, PMB 3, Townsville MC, Queensland 4810, Australia.|ARC Centre of Excellence for Coral Reef Studies, James Cook University, Queensland 4811, Australia.
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JM
Lough
Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat, Western Australia 6014, Australia.
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M
Feng
School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|ARC Centre of Excellence for Coral Reef Studies, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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AJ
Kuret
School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|ARC Centre of Excellence for Coral Reef Studies, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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Clarke
School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|ARC Centre of Excellence for Coral Reef Studies, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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Ricca
School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|ARC Centre of Excellence for Coral Reef Studies, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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K
Rankenburg
School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|UWA Oceans Institute, 39 Fairway, Nedlands, Western Australia 6009, Australia.|ARC Centre of Excellence for Coral Reef Studies, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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McCulloch
D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D057894:Coral Reefs; D017753:Ecosystem; D006358:Hot Temperature; D019156:Indian Ocean; D010140:Pacific Ocean; D012623:Seawater; D013312:Stress, Physiological / Q000502:physiology*; D014904:Western Australia