emirates7 - Australia’s Great Barrier Reef has experienced its most significant in coral cover in two of its three regions over the past year, according to new research released Wednesday, following one of the most severe mass bleaching events ever recorded.

The Australian Institute of Marine Sciences (AIMS) reported that coral cover in both the northern and southern parts of the reef has declined by 25% to 33%—the largest annual decrease seen since monitoring began 39 years ago. This follows several years of steady coral growth.

“We're seeing growing instability in hard coral cover,” said Mike Emslie, head of the AIMS Long-Term Monitoring Program. “This trend has become more evident over the last 15 years and signals mounting stress on the ecosystem.”

The Great Barrier Reef, recognized as the world’s largest living structure, extends roughly 2,400 kilometers (1,500 miles) along Queensland’s northeastern coastline.

Since 2016, the reef has endured five mass bleaching events during summer seasons. These occur when corals lose their color due to heat stress, making them more vulnerable to death.

The 2024 bleaching event was the most widespread ever recorded, affecting all three regions of the reef with high to extreme levels of bleaching, the report added.