healthy coral reef - coral coe
Original Published Date: 
Monday, November 8, 2021

Full article issued by The ARC Centre of Excellence for Coral Reef Studies.

A new ARC-supported study has revealed the impacts of multiple climate extremes on coral reefs over the past three decades, with only 2% of the Great Barrier Reef escaping bleaching in that time.

Lead researcher Professor Terry Hughes from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) said the frequency, intensity and scale of climate extremes is changing rapidly due to global warming and this includes the record-breaking marine heatwaves that cause corals to bleach and die.

'We no longer have the luxury of studying individual climate-related events that were once unprecedented or very rare,' Professor Hughes says.

'Instead, as the world gets hotter, we have to understand the effects of sequences of rapid-fire catastrophes, as well as their combined impacts.'

The study shows only 2% of the Great Barrier Reef has escaped bleaching since the first event in 1998, then the world’s hottest year on record. Bleaching is a stress response by overheated corals during heatwaves, where they lose their colour and many struggle to survive. Eighty percent of reefs bleached severely in 2016, 2017 and 2020.

The Great Barrier Reef is comprised of more than 3,000 individual reefs stretching for 2,300km. The ecosystem supports 65,000 jobs in reef tourism, and globally, hundreds of millions of people depend on the survival of coral reefs for their livelihoods and food security.

Photo credit: 

A healthy reef. Credit: Morgan Pratchett.