Alarming new study shows much of Great Barrier Reef has been destroyed by bleaching

A COLOSSAL bleaching event has “cooked” our iconic Great Barrier Reef and destroyed much of it forever, a devastating new study has found.

A MASSIVE underwater heatwave has “cooked” our iconic Great Barrier Reef and much of it will never recover, according to a devastating major long-term study.

The results have prompted scientists to confirm that rising sea temperatures are having a greater impact on the Great Barrier Reef than first thought.

Branching corals that act as a nursery for juvenile marine life and give the World Heritage-listed icon its three dimensional aspect experienced a catastrophic die-off following bleaching in 2016, a new study shows.

The paper, published in the scientific journal Nature, details how that particular marine heatwave has sparked a radical shift in the composition of the reef.

The underwater heatwave may have changed the reef forever. Picture: Getty

It means large swathes of mature and diverse clusters have been transformed into a degraded reef structure, Queensland coral reef scientist Professor Terry Hughes says.

“We’ve been saying for a long time that these bleaching events are going to get more frequent and the consequence of that will be that the mix of species will change,” Prof Hughes said.

“(But) there’s a big difference between making a prediction and then measuring it come to pass.”

In years to come, sprawling and intricately shaped coral species such as the staghorn variety will be largely replaced by flat, mound-shaped formations.

“Overall we’ll probably have less coral and overall we’ll have less biodiversity,” Prof Hughes said.

The paper repeated previous science suggesting parts of the reef may never recover from the 2016 bleaching, and again called for more urgent action to prevent its decline as a result of climate change.

The reef brings in $6.4 billion from tourism every year. Picture: Mark Kolbe/Getty Images for Tourism Queensland

Whether or not targets such as those set out in the Paris climate agreement are met, Prof Hughes said a major transition in the reef’s appearance was already well under way.

Responding to questions about the study on Wednesday, Queensland Premier Annastacia Palaszczuk said her government would continue to fund measures to protect what she described as one the state’s greatest natural assets.

A Deloitte Access Economics report in June valued the reef at $56 billion, underpinning 64,000 direct and indirect jobs, which contributed $6.4 billion to Australia’s national economy each year.

It warned of the vast economic consequences for Australia unless more is done to protect the reef.

— AAP