Thomas M. DeCarlo, Anne L. Cohen, George T. F. Wong, Kristen A. Davis, Pat Lohmann, Keryea Soong

Scientific Reports

Published date March 23, 2017

Mass coral mortality under local amplification of 2 °C ocean warming

  • States that sea surface temperature in June 2015 in the South China Sea (SCS) increased by 2°C (in response to El Niño); reports that this amount was unlikely to cause widespread damage to coral reefs
  • Adds that on the Dongsha Atoll, in the northern South China Sea, unusually weak winds created low-flow conditions that amplified the 2°C basin-scale anomaly
  • States that water temperatures on the reef flat, normally indistinguishable from open-ocean SST, exceeded 6 °C above normal summertime levels and that mass coral bleaching quickly ensued, killing 40% of the resident coral community in an event unprecedented in at least the past 40 years
  • Findings highlight the risks of 2 °C ocean warming to coral reef ecosystems when global and local processes align to drive intense heating, with devastating consequences
  • Concludes that the extreme temperature (36 °C) reached in June 2015 was a result of global (El Niño warming superposed upon a global warming trend), regional (high pressure system and reduced winds), and local hydrodynamic (shallow reef, neap tide and unusually slow currents) factors aligning – at the right time – to drive intense heating