Record El Niño threatens Great Barrier Reef bleaching

Scientists have warned that the Great Barrier Reef faces a very high risk of severe and widespread coral bleaching this year, with the potential to trigger localized species extinctions and widespread ecosystem collapse, as a record-strength El Niño develops in the Pacific Ocean. The warnings were delivered at the International Coral Reef Symposium in Auckland, New Zealand, on Tuesday, July 21, 2026.

Marine conservation ecologist Morgan Pratchett, from James Cook University in Queensland, told the symposium that the extreme El Niño is a significant concern. He stated it is a very high likelihood that there will be high-severity, large-scale mass bleaching on the Great Barrier Reef. Pratchett added it is not outside the realm of possibility that the next major disturbance could lead to localized species extinctions and widespread ecosystem collapse.

The El Niño phenomenon, a natural climate cycle characterized by warming sea surface temperatures in the central and eastern equatorial Pacific, is forecast to break records for overall strength this year. This warming shifts global weather patterns and raises ocean temperatures around Australia, increasing the likelihood of the...