The Great Barrier Reef Marine Park Authority's (GBRMPA) Coral Bleaching Response Plan comes into action at the start of each Australian summer. It details the process for forecasting, monitoring and responding to coral bleaching in the Great Barrier Reef Marine Park. This high level of preparation is necessary due to the large area and remote reefs of the Marine Park. The tools and programs in place to forecast and monitor bleaching conditions ensures we have accurate information. This information allows us to manage these events efficiently.

Forecasting coral bleaching conditions

Sea temperature is the single greatest predictor of coral bleaching. Sea temperatures of 1-2^oC above the long-term summer average cause stress to corals, which may lead to bleaching, and potentially death, if high temperatures continue. 

We use reliable sea temperature forecasts of up to six months in advance provided by:

• Predictive Ocean Atmosphere Model for Australia (POAMA)
  
• National Oceanic and Atmospheric Administration (NOAA) in the United States

 The risk of sea temperatures increasing depends on local and regional weather patterns including:

• cyclone activity
• El Niño or La Niña
• regional water temperature
• local air temperature
• cloud cover
• wind and rainfall
• fine-scale ocean circulation patterns.

During periods of high rainfall, the GBRMPA also refers to forecasts of sea surface salinity in order to determine the likely effects on inshore reef regions.

Monitoring coral bleaching

We monitor the actual conditions during summer using:

• ReefTemp  (joint initiative with CSIRO and Bureau of Meteorology)  - provides daily maps of sea surface temperature conditions around Australia
  

• The BleachWatch  program.  This community-based monitoring program encourages Marine Park users (tourism operators, fishers), scientists and other volunteers to report any observations of bleaching. We also evaluate reef health reports provided by the Queensland Parks and Wildlife Service rangers. This information provides a snapshot of current levels of bleaching on the Reef.