Extent of Ningaloo coral bleaching not to be known for another six to 18 months, State Government says

The full impact of widespread coral bleaching of the iconic Ningaloo Reef may not be known for up to 18 months, experts have warned, while the Government continues to monitor the alarming situation. Ningaloo, a UNESCO World Heritage site teeming with marine life, is showing startling signs of widespread coral bleaching as warmer ocean temperatures push the fragile ecosystem to the brink. Researchers have been sounding the alarm for the State Government to take urgent action. Ningaloo Reef is experiencing coral bleaching due to a severe marine heatwave caused by a large mass of warm water from the Kimberley region moving south, significantly warming the waters off WA. Sea surface temperatures have risen dramatically, over 4C warmer than average summer temperatures. This temperature increase puts stress on corals, leading them to expel their zooxanthellae, the microscopic algae that provide them with nutrients and colour. In a recent survey of 21 sites across Ningaloo Reef, Curtin University researchers Zoe Richards and David Juszkiewicz found that while coral death ranged from one to 5 per cent, some shallow areas along the northern section of the reef showed bleaching of up to 90 per cent of corals — including species that are more than 100 years old. In February, former environment minister Reece Whitby told the Midwest Times he had called for an urgent briefing to understand the full extent of damage to Ningaloo Reef. Since then, scientists continue to observe and document the bleaching, with the Department of Biodiversity, Conservation and Attractions saying the full impacts of the heatwave may not be known for another six to 18 months. Following the March State election, Matthew Swinbourn took over as Environment Minister. A State Government spokesperson told the Midwest Times this week that Mr Swinbourn was aware of the coral bleaching at Ningaloo Reef. They assured the State Government, in collaboration with relevant departments, would continue to closely monitor the ongoing marine heatwave event. “DBCA marine scientists, regional teams and external collaborators have been monitoring this marine heatwave event for the past three months, including rapid in-water surveys at priority sites,” the spokesperson said. “As part of its ongoing long-term monitoring program, DBCA will continue to monitor the impacts of the event across the rest of 2025, and into subsequent years. “This will include a combination of aerial and in-water surveys of corals, as well as other components of the ecosystem including fish, invertebrates, seagrass and mangroves.” Australian Marine Conservation Society WA director Paul Gamblin said: “This marine heatwave is like an underwater bushfire raging along Western Australia’s coast killing tens of thousands of fish that washed up on Pilbara beaches and now it’s cooking Ningaloo, the jewel in the crown. “We called for the WA Government to address this destructive marine heatwave weeks ago after the fish kill, and there has been silence at the ministerial level. Surely now that there is such widespread bleaching at Ningaloo, someone in government will step up.” Oceanographer from the Australian Institute of Marine Science Dr Jessica Benthuysen said monitoring showed the warmer temperatures had reached to at least 300m below the surface.