Record bleaching event – up to 90% coral mortality reported across 1,500km of Western Australia’s coastline.
Hope spots lost – Rowley Shoals, once resilient to past heatwaves, now among the worst affected.
Ripple effects – damage to reefs threatens marine biodiversity, fishing livelihoods, and natural storm protection.
Urgent warning – scientists say unchecked carbon emissions will intensify marine heatwaves and reef destruction.
This is the Ningaloo Coast, along the remote western shoreline of Australia.
It is a UNESCO World Heritage Site, renowned for its pristine beaches and marine tourism. Recently, however, it has received extensive news coverage due to an alarming rise in coral bleaching.
According to scientists, a sustained and intense marine heatwave in Western Australia has devastated coral reefs across an area stretching some 1,500 kilometres. The corals have undergone mass bleaching, marking the fourth such large-scale event in recent years — a development that has left scientists deeply concerned.
Algae living within corals give them their vibrant colours and provide food through photosynthesis. In return, corals offer the algae a safe habitat. This is a prime example of a mutually beneficial symbiotic relationship.
But extreme heat forces corals to expel the algae, leading to bleaching and, ultimately, death. From August 2024 to May 2025, the heatwave — which began building off Australia’s north-western coast — placed severe heat stress on corals.
The extent of the bleaching is now unprecedented. The Western Australia Coral Bleaching Group reports that bleaching and mortality rates range from 30 per cent to 90 per cent.
Particularly distressing are findings from the Rowley Shoals — a group of three remote reefs that had previously escaped the worst of past heatwaves and were regarded as “hope spots”. Tragically, they are now among the worst affected within the 1,500-kilometre impact zone.
Coral bleaching threatens both the safety and the livelihoods of coastal communities. Coral reefs act as natural barriers, absorbing the force of storms and waves. Without them, communities must rely on artificial seawalls — costly, environmentally damaging and less effective alternatives.
Marine life, including fish and other crustaceans, also relies on reefs as safe breeding grounds. A decline in fish populations would severely harm the fishing industry.
The full impact of this bleaching event is still being studied, with results expected by November. However, if carbon emissions are not curbed, heatwaves will become more frequent and intense. The ongoing destruction of coral reefs should serve as a stark wake-up call for the world.