This report is compiled by the Climate Change Response Programme of the Great Barrier Reef Marine Park Authority. The Climate Change Response Programme provides regular reports on conditions on the Great Barrier Reef throughout summer and publishes early warnings of increases in levels of stress or widespread bleaching of corals.

Updated March 26 2007

Current Conditions Report March 2007

This is the final current conditions report for the summer of 2006-07. On the basis of current conditions and forecasts the threat of widespread coral bleaching for the Great Barrier Reef region has now passed.

Sea surface temperatures for most of the Great Barrier Reef remained just slightly above the long-term average for March, but did not exceed levels known to cause coral bleaching (Figure 1).

Figure 1. ReefTemp image of anomalous sea surface temperatures viewed in the Google EarthTM mapping service

Sea surface temperatures are measured using remote sensing tools (ReefTemp, NOAA) and reef-based weather stations (ReefFutures). Seasonal weather patterns have been influenced by an El-Niño event (Bureau of Meteorology), which has weakened over recent months and has now diminished for this season.  The active monsoon system that prevailed over northern Australia during late February / early March, bringing heavy cloud cover and heavy rains to much of the region, has now waned. There is a chance that an active monsoon system will re-develop towards the beginning of April, although this will not increase the risk of bleaching for the Great Barrier Reef region. Sea surface temperature forecasts suggest that temperatures will continue to decrease with the onset of autumn, (Figure 2).

Figure 2. Predicted sea surface temperature anomaly for April 2007 (POAMA 26 March 2007)

BleachWatch observers are reporting that reef flat corals seen to pale slightly in the central and northern Great Barrier Reef are returning to normal colouration. The Climate Change Response Team will resume reporting on Current Conditions at the beginning of summer 2007-08.

The Climate Change Response Programme encourages reef users to visit the Climate Change pages of the website for more information. The Great Barrier Reef Marine Park Authority welcomes any reports of coral bleaching. If you regularly visit a reef site, or if you have seen bleaching on the reef, you can submit a BleachWatch monitoring form. For more information on becoming a BleachWatch observer go to the BleachWatch website.

Related links

• ReefTemp is a remote sensing tool used for tracking persistent sea surface temperature anomalies that may be stressful to corals
• NOAA provides regular updates of ‘hotspot’ temperature anomalies at global and regional scales
• ReefFutures synthesises information from a variety of sources on the Great Barrier Reef including weather stations and temperature loggers at reef sites
• The Bureau of Meteorology maintains a regular commentary on the El Nino-Southern Oscillation
• POAMA uses a coupled ocean / atmosphere model to forecast sea surface temperature anomalies months in advance, indicating the likelihood of bleaching-inducing conditions
• BleachWatch is a volunteer programme of observers who visit the Great Barrier Reef regularly and report on the condition of the Reef. It is a part of GBRMPA’s Coral Bleaching Response Plan.