World-renowned coral ecosystems along the coast of Western Australia have been devastated by the worst coral bleaching event on record, resulting from an unprecedented marine heatwave that lasted longer and was more intense than previously seen. According to scientists, this crisis began last August and extended through May, leading to alarming heat stress levels across a staggering 1,500 kilometers (932 miles) of reef. The warm waters forced corals to expel the algae essential for their survival, initiating a bleaching process that poses a significant threat to the reefs’ health.
Preliminary findings suggest that a period of just eight weeks of heat can be lethal for corals, and early assessments indicate that many reefs in WA have experienced loss rates between 15% and 30%. James Gilmour from the Australian Institute of Marine Science (Aims) expressed concern over the extreme conditions, stating, “The length and intensity of heat stress, and its wide-reaching footprint across multiple regions, is unprecedented for most Western Australian reefs."
A newly released report notes that the impact on WA's coral reefs during the 2024-25 season represents the most severe coral bleaching ever documented. Areas that were previously deemed resilient, such as the Rowley Shoals, north Kimberley, and Ningaloo Reef, have now been adversely affected, signaling a worrying trend as climate change continues to escalate.
Ningaloo Reef, a site recognized as a World Heritage Area, now reflects a grim reality similar to the Great Barrier Reef, which has also faced significant coral loss in the past few years. Recently, the Great Barrier Reef experienced its largest decline in coral cover in nearly four decades, further underscoring the urgency of the situation.
Federal Environment Minister Murray Watt stated that the damage to Ningaloo reinforces the critical need for immediate global action, including achieving net zero emissions. Experts warn that climate change is making bleaching incidents more frequent and severe, allowing inadequate recovery time for coral reefs that typically need 10 to 15 years to recuperate.
Dr. Gilmore warned that carbon emissions are the leading threat to coral reefs worldwide. Alarmingly, the UN has previously highlighted that even if global warming is limited to 1.5°C above pre-industrial levels, between 70% and 90% of the world’s tropical coral reefs could perish, highlighting the urgent need for global action on climate issues.
