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Coral Bleaching of the Great Barrier Reef

Published on: 12th April, 2016 | Conservation
Photo credit: Bleached coral
More than 1,000 km of the Great Barrier Reef is showing signs of significant bleaching and it is expected that many corals will die in the worst affected areas.

 A major El Nino event this summer resulting in warmer than average water temperatures combined with ongoing trends of ocean warming has resulted in the worst ever bleaching episode in the known history of the Great Barrier Reef.

Aerial surveys were carried out to determine the extent of the episode predicted to occur in October 2015.  The predictions included bleaching in the southern and central areas of the GBR.  However, in January 2016 a scientist at Lizard Island noticed hard corals, soft corals and clams showing signs of bleaching.  The aerial survey showed that the extent of bleaching was not limited to just the area around Lizard Island.

It is now believed that the northern areas have been hit the hardest with 95% of reefs between Cairns and Papua New Guinea showing significant signs of bleaching.

The surveys so far have determined that the severity of bleaching declines from north to south.  However, it is thought that all of the reefs in the GBRs remote far northern section have been hit hard.  It is expected that many of the corals in this region will die.

Moving south the bleaching is more variable.  Some reefs have been hit hard and others much more moderately.

In the southern regions the bleaching is even more variable and generally less severe.

The surveys to date have established that at least 1,000 km of the GBR has been affected.  Work continues by the National Coral Bleaching Taskforce to gain a complete picture of the severity and consequences of this event.

The original article ‘Coral Bleaching Taskforce: more than 1,000 km of the Great Barrier Reef has bleached’ by Pratchett and Lough is available here

AUTHOR

Susan Shield

TDI Adv. Nitrox & Deco. Procedures. Chartered Professional Engineer