Bleaching Watch on the Great Barrier Reef

Image: Stunning Heron Island



Successful Surveying


The team has just wrapped up our expedition to Heron Island on the southern Great Barrier Reef (GBR), where it all began for the XL Catlin Seaview Survey back in 2012.  Over six days we surveyed 11 sites (about 20km of reef) on four different islands in the Capricorn Bunker Group, the southern-most region of the GBR.  Weather conditions were extremely favourable for our survey.  Winds and swell conditions were exceptionally calm for this time of year, allowing our team to reach exposed and sheltered reefs not only surrounding Heron Island, but also three other reefs in the vicinity: Wilson Island, Wreck Island, and One Tree Island.


The survey locations were spread across different coral reef management zones (Green – Marine National Park, Pink – Protected, and General Use). Some of these locations were previously surveyed in 2012 and 2014, so the outcomes of this expedition will provide further understanding of reef composition changes over time and space.  Besides very favourable weather conditions, the success of this expedition was also due to the tremendous support of The University of Queensland’s Heron Island Research Station and the Global Change Institute crew.



On Bleaching Watch


This expedition also aimed to assess the occurrence and extent of coral bleaching, an important and devastating event for coral reefs which is currently happening at its full extent in the northern GBR as part of the third ever global coral bleaching event.   Preliminary observations show <1% coral bleaching, indicating that these reefs are still in great shape. However these reefs form just a small portion of the GBR safe from the damaging temperature currently recorded for central and northern regions of the GBR and Coral Sea Atolls.


During the surveys, our team also engaged with the National Geographic documentary crew, who are filming a series on the impacts of climate change. This has been an exciting opportunity for us to communicate how climate change can impact coral reefs, but also how innovative technology like the XL Catlin Seaview Survey can contribute a more broad and rapid understanding of massive disturbance events such as the current third major global bleaching event.



Next, to the North


Following our monitoring efforts on the GBR during 2012 and 2014, the team is now getting ready to assess the aftermath of the reported bleaching of 95% of the northern GBR.  Later this year, we will resurvey 30-40 sites in the off-shore reefs between Cairns and the Torres Strait.  Research findings from the surveys will be important in helping the government target management actions for reefs damaged by coral bleaching.