QUEENSLAND: Marine scientists have warned that Australia’s Great Barrier Reef is facing a severe and widespread bleaching event that could escalate into an “ecosystem collapse,” driven by the effects of this year’s El Niño climate phenomenon.
The Great Barrier Reef, which stretches along the Queensland coast, is the world’s largest coral reef system. It recently escaped being placed on Unesco’s List of World Heritage in Danger.
Morgan Pratchett, a marine ecologist at James Cook University in Queensland, said the intense El Niño is a major cause for concern.
This year’s event is expected to set records for intensity, with rising sea surface temperatures in the central and eastern tropical Pacific triggering global shifts in wind patterns, atmospheric pressure and rainfall.
Hard coral cover across the reef declined substantially in 2024-2025, with above-average water temperatures causing the reef’s sixth mass coral bleaching event since 2016.
Scientists are now concerned that the looming El Niño could cause further detrimental damage to the reef. This year’s El Niño is expected to break records for its overall strength as it warms surface temperatures in the central and eastern equatorial Pacific Ocean, bringing worldwide changes in winds, pressure and rainfall patterns.
In the Great Barrier Reef, this could mean the localised extinction of species, and potentially widespread ecosystem collapse.
“It’s a very high likelihood that we’ll see very high severity and large-scale mass bleaching on the Great Barrier Reef,” Pratchett said.
Unesco has been monitoring the reef annually since 2021, when it warned it was at risk of being placed on the List of World Heritage Sites “in danger.”
Extreme weather, land-based runoff, coastal development and predation by the crown-of-thorns starfish were also placing the reef under pressure. – Agencies
