Record-breaking coral bleaching lays waste to WA's most prized reefs
While the full impact is still unfolding, experts from numerous organisations and agencies forming the WA Coral Bleaching Group have so far reported bleaching and mortality ranging from medium (11-30 per cent) to extreme (90 per cent) levels across systems up to 1500 kilometres apart.
A summary released on Tuesday says researchers found 31-60 per cent bleaching and mortality at Ningaloo Reef monitoring sites, and 61-90 per cent mortality at Mermaid and Clerke Reefs, Rowley Shoals.
At inshore southern Kimberley reefs, they recorded 31-60 per cent bleaching with mortality in March; at Ashmore Reef, they recorded 11-30 per cent bleaching and mortality with one site at 31-60 per cent.
Members of the bleaching group, convened by the Australian Institute of Marine Science, first began monitoring the heatwave in September. Heat stress peaked in December, January and again in March/April. Temperatures only began to drop in May.
'Areas which had given us hope because they'd rarely or not bleached before, like the Rowley Shoals, north Kimberley and Ningaloo, have been hit hard this time,' AIMS senior research scientist Dr James Gilmour said.
'The length and intensity of the heat stress, and its footprint across multiple regions, is something we've never seen before on most of the reefs in WA.'
The stress is expected to beat records set during the 2011 La Nina and the 2016 El Nino on all but the southernmost reefs.
The full impact was still being assessed, and some bleached coral may recover, but it can take a coral reef 10-15 years to recover fully.
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West Australian
14 hours ago
- West Australian
Environment Minister says ‘global action' is needed to save WA's Ningaloo Reef, rejects 2030 target
WA's Environment Minister says global action is more important than a local 2030 emissions target, after scientists revealed the extent of a 'catastrophic' coral bleaching event at Ningaloo Reef. While researchers are still assessing the damage caused by a marine heatwave, the Australian Institute of Marine Science has confirmed the worst bleaching ever recorded off the WA coast. 'The length and intensity of the heat stress, and its footprint across multiple regions, is something we've never seen before on most of the reefs in WA,' the institute's senior research scientist James Gilmour said. 'Areas which had given us hope because they'd rarely or not bleached before, like the Rowley Shoals, north Kimberley and Ningaloo, have been hit hard this time.' Sensitive to heat stress, corals expel the algae living in their tissues in warm water, causing the coral to go pale. Environment Minister Matthew Swinbourne said the Government was monitoring the situation and was 'obviously' concerned. 'I went up to Exmouth and to the North-West Cape a couple of weeks ago, got a chance to see it for myself,' he said on Tuesday. 'It was obvious to me that this was not the normal state of the reef. 'In terms of the imperative around climate, it doesn't change that. It's been an imperative for a long time . . . we remain committed to dealing with our carbon emissions. 'We're getting out of coal in WA, we're pushing forward a renewable energy program that will hopefully see us decarbonising our economy as effectively as we can.' Mr Swinbourne said Labor's climate legislation, that was shelved before the March election is being re-written. He rejected the Greens' private members bill, being put to Parliament on Thursday, that would legislate a 2030 target for emissions. 'We need to be careful in terms of what we set and what we can achieve,' Mr Swinbourne said. 'What you want to do is you want to make achievable targets. It's all well and good to send a virtual signaling type of target, which is often advocated by the Greens, but actually these things don't happen in a vacuum. 'They affect other areas of our economy, other areas of our lives and so there's always a balance with these sorts of things.' Bleaching is not always fatal but if underwater heat is prolonged and severe, corals can die. Sea surface temperatures around Australia last summer were the warmest on record since 1900, with coral heat stress peaking in January. Conditions varied across the tropical reefs spanning 1500km - from 'extreme', or 90 per cent bleached or dead, to 'medium', somewhere between 11 per cent and 30 per cent. Mermaid and Clerke reefs in the Rowley Shoals, 300km west of Broome, recorded 'very high' levels of mortality, between 61 per cent and 90 per cent. The World Heritage-listed Ningaloo Reef, known for its whale sharks, experienced 'high' bleaching and mortality between 31 per cent and 60 per cent. Dr Gilmour said climate change was driving the increased frequency and severity of mass coral bleaching events and giving them little time to bounce back in between. 'They need 10 to 15 years to recover fully,' he said. 'The key to helping coral reefs survive under climate change is to reduce greenhouse gas emissions.' Mr Swinbourne called it a 'global level' event and said WA cannot go it alone. 'All that we could do in WA is likely to be meaningless if we don't have global action on climate change,' he said. 'The issue there is we have seen some of our big partners walk away from their commitments and that's what's most alarming because the efforts that we take here in WA will be paled into insignificance. 'It's a matter of public record that the US has walked away from many of its commitments. We have seen, of course, parts of the Liberal party here in WA throw up their climate denialism and walking away from a net zero target by 2050, which is also alarming.' Outside Parliament on Tuesday, Liberal leader Basil Zempilas didn't want to talk about his support for the 'status quo' on net zero. 'That's not my focus today, I might add that it's not the focus of the West Australians that I've spoken to in the last 24 hours,' he said. 'Today's focus for this State Government, and for us as the Opposition, is an accountability and transparency in the health area.' Greens MP Sophie McNeill accused both major parties of inaction and said WA's tourism industry will pay the price. 'More than 1000 West Australians work in Exmouth in tourism, they love that reef,' she said. 'And their hearts are broken. It was absolutely shocking to see what's happened to our beautiful Ningaloo on this Government's watch. 'It is the worst Government in the whole country when it comes to climate action. No 2030 target, no renewable energy target and now our stunning beautiful world heritage Ningaloo is dying on its watch.' The updates on coral health land ahead of the expected release of the Federal Government's 2035 climate goals, due in September under the Paris Agreement rules.
Sydney Morning Herald
19 hours ago
- Sydney Morning Herald
Record-breaking coral bleaching lays waste to WA's most prized reefs
Last summer's marine heatwave off the West Australian coast was the longest, largest and most intense on record for the state, resulting in its most widespread coral bleaching event ever recorded. While the full impact is still unfolding, experts from numerous organisations and agencies forming the WA Coral Bleaching Group have so far reported bleaching and mortality ranging from medium (11-30 per cent) to extreme (90 per cent) levels across systems up to 1500 kilometres apart. A summary released on Tuesday says researchers found 31-60 per cent bleaching and mortality at Ningaloo Reef monitoring sites, and 61-90 per cent mortality at Mermaid and Clerke Reefs, Rowley Shoals. At inshore southern Kimberley reefs, they recorded 31-60 per cent bleaching with mortality in March; at Ashmore Reef, they recorded 11-30 per cent bleaching and mortality with one site at 31-60 per cent. Members of the bleaching group, convened by the Australian Institute of Marine Science, first began monitoring the heatwave in September. Heat stress peaked in December, January and again in March/April. Temperatures only began to drop in May. 'Areas which had given us hope because they'd rarely or not bleached before, like the Rowley Shoals, north Kimberley and Ningaloo, have been hit hard this time,' AIMS senior research scientist Dr James Gilmour said. 'The length and intensity of the heat stress, and its footprint across multiple regions, is something we've never seen before on most of the reefs in WA.' The stress is expected to beat records set during the 2011 La Nina and the 2016 El Nino on all but the southernmost reefs. The full impact was still being assessed, and some bleached coral may recover, but it can take a coral reef 10-15 years to recover fully.
The Age
19 hours ago
- The Age
Record-breaking coral bleaching lays waste to WA's most prized reefs
Last summer's marine heatwave off the West Australian coast was the longest, largest and most intense on record for the state, resulting in its most widespread coral bleaching event ever recorded. While the full impact is still unfolding, experts from numerous organisations and agencies forming the WA Coral Bleaching Group have so far reported bleaching and mortality ranging from medium (11-30 per cent) to extreme (90 per cent) levels across systems up to 1500 kilometres apart. A summary released on Tuesday says researchers found 31-60 per cent bleaching and mortality at Ningaloo Reef monitoring sites, and 61-90 per cent mortality at Mermaid and Clerke Reefs, Rowley Shoals. At inshore southern Kimberley reefs, they recorded 31-60 per cent bleaching with mortality in March; at Ashmore Reef, they recorded 11-30 per cent bleaching and mortality with one site at 31-60 per cent. Members of the bleaching group, convened by the Australian Institute of Marine Science, first began monitoring the heatwave in September. Heat stress peaked in December, January and again in March/April. Temperatures only began to drop in May. 'Areas which had given us hope because they'd rarely or not bleached before, like the Rowley Shoals, north Kimberley and Ningaloo, have been hit hard this time,' AIMS senior research scientist Dr James Gilmour said. 'The length and intensity of the heat stress, and its footprint across multiple regions, is something we've never seen before on most of the reefs in WA.' The stress is expected to beat records set during the 2011 La Nina and the 2016 El Nino on all but the southernmost reefs. The full impact was still being assessed, and some bleached coral may recover, but it can take a coral reef 10-15 years to recover fully.
