A mass coral reef bleaching event at One Tree Island in the southern Great Barrier Reef has been described as “the worst ever seen” by UTS marine scientists.
Professor David Booth, marine ecologist and former president of the Australian Coral Reef Society, is surveying the coral habitat and fish species at One Tree Island and says it’s clear a widespread bleaching event is occurring.
“I have been monitoring coral habitat and key fish populations at One Tree Island for a quarter of a century now, including recording the demise of corals and associated fishes here after the 1998 bleaching event,” said Professor Booth, who is working with fellow UTS researcher Gigi Beretta.
“We have a big bleaching event on our hands – for me, it’s the worst I have seen.”
Professor Booth this week spoke to the senate inquiry into current and future impacts of climate change on marine fisheries and biodiversity from the One Tree Island research station. He called for better support for long-term monitoring studies, education and the establishment of a national coordination body.
“From Australia’s point of view, we are a major coal exporter to the world, and coal is a key contributor to global warming,” he said. “Hard choices need to be made by governments to curtail this and forgo some profits in favour of stewardship of our wonderful reef.”
Professor Booth’s reports from One Tree Island coincide with research published in Nature by Australian and international researchers, who say the 2016 Great Barrier Reef bleaching event affected 91 per cent of individual reefs.
Coral bleaching is caused primarily by high sea temperatures. Even increases of just 1C over a period of four weeks can trigger a bleaching event. Bleached corals can recover if conditions return to normal, but often bleached corals that experience prolonged (or repeat) stress die, with a flow-on effect to other marine organisms.
Associate Professor David Suggett, leader of the Future Reefs research program at UTS, said many parts of the Great Barrier Reef are experiencing an unprecedented second year of mass bleaching.
“We have now reached a stage of coral loss that was predicted for 20 to 30 years’ time,” he said.
“While we must tackle climate change immediately and head on, we need complementary and innovative reef management platforms to ensure we have reefs until mitigation can take effect.”
Although it is too soon to know if, or how much, these corals will recover, Professor Booth and Associate Professor Suggett agree mass bleaching is causing irreparable damage to the Great Barrier Reef.
“Severe coral bleaching that was virtually unknown before 1980 is now becoming an annual occurrence, with corals not having sufficient time between events to fully recover,” Professor Booth said.
“Urgent action is needed to curb greenhouse emissions and Australia is in a strong position to show global leadership on this important issue.”
Associate Professor Suggett said: “The time frame to intervene is rapidly diminishing. We are calling for urgent, coordinated and integrated action to prevent further damage before it’s too late.”