A framework for comparing coral bleaching thresholds

Coral reefs are highly vulnerable to bleaching under elevated temperature. Since 2002, NOAA Coral Reef Watch has used a bleaching threshold based on global sea surface temperatures to provide operational bleaching warnings. Recent studies suggest that modifications to the current global bleaching prediction method may result in higher predictive power. Here, we present a method for comparing four bleaching prediction methods at different spatial and temporal resolutions, each calibrated against the global bleaching observational dataset from ReefBase between 1985 and 2005. We identify one method (“MMMmax”) that consistently gives the highest predictive power at all spatial and temporal resolutions examined. An improved bleaching threshold will refine future bleaching projections under climate change and provide more reliable real-time bleaching alerts to international coral reef managers.

[1]  M. Karnauskas,et al.  Predicting coral bleaching hotspots: the role of regional variability in thermal stress and potential adaptation rates , 2012, Coral Reefs.

[2]  S. Donner.  An evaluation of the effect of recent temperature variability on the prediction of coral bleaching events. , 2011, Ecological applications : a publication of the Ecological Society of America.

[3]  T. Oliver,et al.  Do fluctuating temperature environments elevate coral thermal tolerance? , 2011, Coral Reefs.

[4]  Kenneth S. Casey,et al.  New insights into global patterns of ocean temperature anomalies: implications for coral reef health and management , 2010 .

[5]  R. van Woesik,et al.  Corals escape bleaching in regions that recently and historically experienced frequent thermal stress , 2009, Proceedings of the Royal Society B: Biological Sciences.

[6]  S. Donner.  Coping with Commitment: Projected Thermal Stress on Coral Reefs under Different Future Scenarios , 2009, PloS one.

[7]  M. Huber,et al.  Quantifying the quality of coral bleaching predictions , 2009, Coral Reefs.

[8]  Mebrahtu Ateweberhan,et al.  EFFECTS OF CLIMATE AND SEAWATER TEMPERATURE VARIATION ON CORAL BLEACHING AND MORTALITY , 2007 .

[9]  James E. Palardy,et al.  Heterotrophic plasticity and resilience in bleached corals , 2006, Nature.

[10]  Elizabeth C. Kent,et al.  Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century , 2003 .

[11]  Fred Wells,et al.  Marine Biodiversity Hotspots and Conservation Priorities for Tropical Reefs , 2002, Science.

[12]  J. Palutikof,et al.  Climate change 2007 : impacts, adaptation and vulnerability , 2001 .

[13]  P. W. Glynn,et al.  Experimental evidence for high temperature stress as the cause of El Niño-coincident coral mortality , 1990, Coral Reefs.

[14]  S. Coles,et al.  Effects of temperature on the mortality and growth of Hawaiian reef corals , 1977 .

[15]  P. Boylan,et al.  New insights into the exposure and sensitivity of coral reefs to ocean warming , 2009 .

[16]  R. Berkelmans,et al.  Coral Bleaching in Space and Time , 2009 .

[17]  J. Lough,et al.  Climate Variability and Change: Monitoring Data and Evidence for Increased Coral Bleaching Stress , 2009 .

[18]  W. Skirving,et al.  Global assessment of coral bleaching and required rates of adaptation under climate change , 2005, Global change biology.

[19]  A. Strong,et al.  APPLYING MCSST TO CORAL REEF BLEACHING , 1995 .

[20]  J. Hendee,et al.  An assessment of global warming stress on Caribbean coral reef ecosystems , 1992 .