Worst Great Barrier Reef bleaching leaves giant coral graveyard – looks like it’s been carpet bombed

Lethal hot water

The academic director of the University of Queensland’s Heron Research Station, Dr Selina Ward, also doesn’t mince words. She describes it as the year of hell.

Storm surges washed away some of their favorite stands of coral, there have been outbreaks of coral-eating crown-of-thorns starfish, cyclones and floods. But these multiple assaults pale in comparison to this most horrific whitewash.

Bleaching peaked in February and March. In late March, Ward visited 16 sites around Heron and nearby reefs, including around One Tree Island, a science reserve with the highest level of protection you can get.

It was terrible, the worst bleaching event I’ve ever seen, he says. At these 16 sites, all were severely bleached and some of the corals were already beginning to die.

Their big question, though, is what’s going on underwater right now.

Corals bleach when sustained exposure to warmer-than-average water causes them to expel the photosynthetic algae that give them their color and from which the coral polyps get much of their nutrients.

A coral can die or recover from bleaching. The weeks following a bleaching event are a brief window in which scientists like Ward and Hughes can assess how many corals have starved without their symbiotic algae. In a few months, these recently dead corals will be overgrown with weeds and begin to break down into piles of barren debris, the timing and cause of their demise becoming ever more obscure.

The reef is now in that window, Ward says, where scientists can go into the water and see how many bleached corals that, while left more vulnerable to disease and less fertile, could regain their color and to throw As well as those who won’t.

But the bleaching is just a coral reaction to what Hughes says is perhaps best described as a warm water event. Some corals will simply cook. Others turn a vivid blue or neon yellow with a striking shade, according to our research vessel pattern, which has spread to the corals around Heron.

These, while dazzling, are also puzzling, this fluorescence is a protein that corals produce as a kind of sunscreen. However, it is not a very effective defense. According to Hughes, most of these neon corals will not survive.

The irony is that it looks beautiful in death, Whish-Wilson says of a fluorescent coral as he and Hughes wade through knee-deep water as the tide recedes around Heron and coral tips emerge from the water like bones .

The unseen national emergency

After the summer of 2023-24, the Great Barrier Reef is awash with cruel irony and dissonance. The first hits the traveler in Heron when his island catamaran leaves its berth and drags down a channel to Gladstones Harbour.

A thick, rusted bow is slowly revealed as a bulk carrier connected, by crane-like loaders, to great piles of crushed black earth. Behind him, another ship is being loaded with coal. And another behind that.

Then, as the catamaran makes its way around Curtis Island, it sinks and weaves its way through bulkhead after bulkhead, lurking outside the harbor like a school of sharks on a reef. In his phone dispatch application, Hughes lists 43 of the steel leviathans.

Whish-Wilson says the flotilla speaks to a government that has a stake in every direction.

But you can’t have a future for fossil fuels and a future for a healthy reef, he says. You just can’t.

Later, reflecting on a trip he already believes will haunt him for the rest of his life, the Greens’ healthy oceans spokesman says this devastating bleaching should prompt Unesco to declare the Great Barrier Reef’s world heritage values ​​as at risk and will require the visit of the Federal Minister of the Environment. , as well as a national emergency declaration.

If it was a wildfire thousands of miles away, he says, that statement would have already been made.

But because it’s in the ocean, it’s out of mind, out of sight.

Less hope for recovery

Another of Herons’ incongruities is that, even in the midst of underwater devastation, it still harbors awe-inspiring beauty. Green sea turtles glide over stands of broken coral, giant coral trout open their mouths and gills for an electric blue napoleon, manta rays glide gracefully through the shallows.

Hughes first came here as a postdoctoral researcher in 1985 and has returned often. Now, as he prepares to leave Heron once more, he ponders the future of a natural wonder of the world to which he has given so much of his life.

The 67-year-old has seen the coral ecosystems of the Great Barrier Reef degrade and knows they are on the inexorable path of further decline. However, if global warming can be limited to well below 2°C at pre-industrial levels, Hughes still believes it is possible to stabilize sea temperatures and allow surviving corals to slowly recover.

It is not a matter of hope or resignation, he says, but of immediate action.

Unless fossil fuel emissions are cut as soon as possible, he says, corals on the world’s reefs will be replaced by something else, perhaps algae or sponges.

There would still be a tropical ecosystem here, Hughes says with a hand. But at some point we should say that it is no longer a coral reef. We have to say it another way.

So when will Hughes return to Heron to see what, if any, he recovers? Will this big bommie, now white as snow, check?

I’m not sure I’ll go back, he says.

And why not? At this, a long pause, as Hughes looks away and into the ocean, the only sound is a muffled sob and the haunting wailing of the blacks who clamber and swarm in this turbulent coral cay.

Because it’s so annoying, he says, finally.

Not that Hughes plans to keep quiet.

I think scientists like me need to be as vocal as possible, he says. To show people what’s going on.