We've known for a while that the Great Barrier Reef is dying, but new numbers from the ARC Centre of Excellence for Coral Reef Studies drive home exactly how much of it has been affected by mass bleaching. Dead and dying staghorn coral in the central Great Barrier Reef. Image: ARC Centre of Excellence for Coral Reef Studies.
Initial estimates show that approximately 35 per cent of the coral on 84 reefs in the northern and central areas are either dead or dying. This is a massive amount of the world's largest coral reef, which spans around 2300km.
Coral bleaching is the result of warmer water temperatures, which causes the coral to expel their symbiotic algae, turning it white and leaving them without the ability to feed or protect themselves from disease. If temperatures cool, coral reefs are usually able to recover.
"This year is the third time in 18 years that the Great Barrier Reef has experienced mass bleaching due to global warming, and the current event is much more extreme than we've measured before," said Professor Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University.
As our planet continues to heat up, this could bring more danger to one of our natural wonders. "We're rapidly running out of time to reduce greenhouse gas emissions," Hughes added.
Luckily, researchers also noted that they expect the temperatures to drop near reefs in more southern areas, as they have stayed closer to normal summer temperatures.
Over the next few months, scientists will continue to monitor the reefs to see how far the bleaching goes.