This report is compiled by the Climate Change Response Programme of the Great Barrier Reef Marine Park Authority (GBRMPA). 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 February 14 2007

Current Conditions Report February 2007

On the basis of current conditions and forecasts the threat of widespread coral bleaching for the Great Barrier Reef region is currently rated as low. 

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

Sea surface temperatures for most of the Great Barrier Reef continue to be lower than the long-term average for February. Sea temperatures 1–2°C above the monthly long-term average cause thermal stress in corals, leading to coral bleaching if elevated temperatures persist.. Temperatures have recently increased slightly above the long-term average for the northern Great Barrier Reef, but remain below levels known to cause coral bleaching (Figure 1).

Sea surface temperatures are measured using remote sensing tools (ReefTemp, NOAA) and reef-based weather stations (ReefFutures). Seasonal weather patterns are influenced by the current El-Niño event (Bureau of Meteorology), which has been weakening over recent months.  A monsoon system has prevailed over northern Australia over recent weeks, bringing heavy cloud cover and heavy rains to much of the region. Sea surface temperature forecasts suggest that average or lower than average temperatures are likely to continue into March for most of the Great Barrier Reef region (Figure 2).

Figure 2 Predicted sea surface temperature anomaly for March 2007 (POAMA 12 February 2007)

BleachWatch observers have reported some slight paling of corals on reef flats in the central and northern Great Barrier Reef. The condition of corals at these sites will be assessed regularly as the summer progresses.

The actual risk of sea temperatures increasing to levels known to be stressful to corals depends on a complex interaction of regional water temperatures, local air temperatures, cloud cover, winds and rainfall. While the threat of mass bleaching is currently low, the Climate Change Response team will continue to closely monitor sea surface temperatures and weather conditions. 

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.