Great Barrier Reef now 93% damaged by coral bleaching, and scientists are spitting fury




‘I have cried. I have broken down in front of cameras. This is the most devastating, gut-wrenching fuck up.’

Professor Justin Marshall from the University of Queensland is talking to The Guardian in unconventionally candid terms. The scientist is deeply upset. And he has good reason to be.

A marine biologist, Marshall is an expert in coral reef health and a specialist in colour vision and communication in sea animals. For over three decades he has been diving and working on the Loomis Reef—one of 3000 reefs that together comprise Australia’s 2,300km-long Great Barrier Reef—but recently he has begun referring to it in the past tense.

As global warming caused by man-made greenhouse gas emissions combines with the effects of El Niño, the underwater world has been gripped in the fist of a devastating heatwave. This is causing a global bleaching event, and the planet’s biggest living feature is providing alarming proof of just how serious the situation is.

New aerial surveys of the Great Barrier Reef have revealed that 93% of the reef has now been impacted by ‘light to severe’ coral bleaching’, and Australia-based scientists have lost the will to be professionally polite about the situation.

Just three mass bleaching events have ever been recorded on the reef, and they’ve all happened in the years since 1997. According to scientists, the current disaster is the worst of the lot. The biggest previous coral calamity occurred in 1997-98, wiping out 16% of the world’s reefs in a single year, and this event is already on a par with that, with models projecting that it will continue in the Pacific until 2017, as well as moving west into the Indian Ocean.

Bleaching occurs when sea temperatures rise and stay warm for an unusual amount of time, which essentially sends the coral into shock. In normal healthy conditions, the process of photosynthesis that takes place between coral polyps and tiny plants creates explosions of kaleidoscopic colour, but when the water heats up this stops happening and the coral turns a ghostly white. If these conditions persist, the coral dies and then becomes covered in dull algae, which is very bad news for a large chunk of the animals living in the enormous ecosystem that revolves around the reef. And for anyone that cares about one of the most extraordinary natural features on the planet.

In November 2015, scientists on the Australian Museum Lizard Island Research Station beginning noting the early signs of coral bleaching, which were revealed through faded colours, odd fluorescent hues and chunks of white.

The Great Barrier Reef aerial survey began in March, and around 911 individual reefs along the 2,300km structure have since been inspected from helicopters and planes. The aerial observations are being confirmed by teams of divers, who are examining the coral up-close. A hundred people have been underwater for the last month, collecting data from around 150 reefs, and the evidence they are supplying has confirmed the birds’ eye reports.

Over half of the reefs surveyed so far have been severely bleached, and that already alarming figure rises to 81% in reefs north of Port Douglas. Professor Terry Hughes, from James Cook University, who heads the National Coral Bleaching taskforce, explained that only 68 of the 911 reefs so far studied have shown no signs of bleaching.

‘We’ve never seen anything like this scale of bleaching before,’ said Hughes. ‘In the northern Great Barrier Reef, it’s like 10 cyclones have come ashore all at once.’ The damage is so extensive, that marine biologists are using terms like ‘bommie apocalypse’.

The Great Barrier Reef isn’t dead. Not yet. The current El Niño—which has been particularly savage, combining with manmade climate change to produce a run of 11 consecutive hottest months on record, worsening natural disasters including the wildfires currently savaging corners of Canada—is now weakening. If the water in the Pacific cools quickly enough, the coral could bounce back. Well, some of it, at least.

However, if the coral remains bleached for a long period, it will die. Professor Hughes has said that the northern region of the reef is already experiencing mortality rates as high as 50%, and he expects that on some sections of reef it will exceed 90%.

Professor David Booth, head of the Australian Coral Reef Society, which represents many of the nation’s most respected marine biologists, says he has never seen scientists so worried. And angry.

‘The visual is shocking but so is the disconnect between the severity of the bleaching and the decisions by governments to approve coalmines and coal infrastructure,’ he told The Guardian. ‘Australia is like a drug dealer for climate change—selling all this coal, but all the while knowing the harm we are doing.’

Dr Mark Eakin, head of the US government’s Coral Reef Watch program, has pointed out that this year’s big bleaching event is conforming with a depressing prediction made by Australian scientist Ove Hoegh-Guldberg after the 1998 disaster. Hoegh-Guldberg opined that coral reefs would catastrophically decline by the middle to end of this century, as the word’s oceans warmed and bleaching outbreaks became an annual occurrence on multiple reefs.

‘What we’re seeing now is unfortunately saying that Ove’s paper was not alarmist,’ Eakin explains. ‘This year is especially telling. In the past, big bleaching events happened pretty much during the course of a year. This current bleaching event started in mid-2014.’