The Great Barrier Reef: a catastrophe laid bare

5 months, 19 days ago

Australias natural wonder is in mortal threat. Bleaching caused by climate change has killed almost a one-quarter of its coral this year and many scientists believe it could be too late for the rest. Employing exclusive photographs and new data, a Guardian special report investigates how the reef has been devastated and what can be done to save it

It was the smell that really have to go to diver Richard Vevers. The smell of demise on the reef.

I cant even tell you how bad I smelt after the dive the smell of millions of rotting animals.

Vevers is a former advertising executive and is now the chief executive of the Ocean Agency, a not-for-profit company he founded to raise awareness of environmental problems.

After diving for 30 years in his spare time, he was compelled to combine his work and hobby when he was struck by the calamities faced by oceans around the world. Chief among them was coral bleaching, caused by climate change.

His job these days is instead morbid. He travels the world documenting dead and dying coral reefs, sometimes gathering photo only ahead of their demise, too.

With the world now in the midst of the longest and probably worst global coral bleaching event in history, its boom time for Vevers.

Even with all that experience, hed never seen anything like the desolation he saw last month around Lizard Island in the northern third of Australias spectacular Great Barrier Reef.

Gallery link: dead and dying coral at Lizard Island on Australias Great Barrier Reef. The once brilliant coral is blanketed by seaweed a sign of extreme ecosystem meltdown

As part of a project documenting the global bleaching event, he had surveyed Lizard Island, which sits about 90 km north of Cooktown in far north Queensland, when it was in full glorious health; then just as it started bleaching this year; then finally a few weeks after the bleaching began.

It was one of the most disgusting sights Ive ever seen, he says.

The hard corals were dead and covered in algae, looks a lot like theyve been dead for years. The soft corals were still dying and the flesh of the animals was decomposing and dripping off the reef structure.

Its the sort of description that would be hard to believe, if it wasnt captured in photographs. In images shared exclusively with the Guardian, the catastrophic nature of the current mass bleaching event on previously pristine parts of the Great Barrier Reef can now be revealed.

Richard Vevers, the founder and chief executive of the Ocean Agency, a not-for-profit that is documenting the longest coral bleaching event in history. Photograph: the Ocean Agency

Coral bleaches when the water its in is too warm for too long. The coral polyps gets stressed and spit out the algae who lives in inside them. Without the colorful algae, the coral flesh becomes transparent, uncovering the stark white skeleton beneath.

And because the algae provides the coral with 90% of its energy, it begins to starve. Unless the temperatures promptly return to normal, the coral dies and get taken over by a blanket of seaweed.

Once that happens it can take a decade for the coral to retrieve and even then that recovery depends on the reef not being hit by other stressors such as water pollution.

Vevers images show how the once brilliant coral first turned white and then became contained within seaweed.

While the hard corals are still holding their structure under the seaweed blanket, the soft corals are succumbing; dripping off the dead coral skeletons.

The thick seaweed is a sign of extreme ecosystem meltdown. Fish can no longer use the coral structure as shelter blocked by the plants and before long the coral structures themselves are likely to collapse, leaving little chance of full recovery within the next 10 years.

When the coral dies, the entire ecosystem around it transforms. Fish that feed on the coral, use it as shelter, or nibble on the algae that grows among it succumbs or move away. The bigger fish that feed on those fish disappear too. But the cascading consequences dont be brought to an end. Birds that eat fish lose their energy source, and island plants that thrive on bird fells can be depleted. And, of course, people who rely on reef for food, income or shelter from waves some half a billion people worldwide lose their vital resource.

1 – before and after images demonstrating white coral after bleaching, and then algae-covered dead coral

Justin Marshall, a biologist at the University of Queensland who expends a lot of his time analyzing the reef ecosystem around Lizard Island, says: What happens is the colony dies, the polyps disintegrate. The algae use that as fertiliser and grow very quickly over the coral head. And at that point its fated. Its going to break up.

Its like a forest where plants compete for sunlight. On the reef youve got this continuous competition between the seaweed and the coral. And, in the conditions weve got at the moment, the seaweed tends to win because its warm and its got lots of rotting stuff around to fertilise it.

Marshall says the thing that struck him about the bleaching event this year was not just the severity but the rapidity of the death. I was just blown away by that.

Once the seaweed has taken hold, and the structure of the reef is broken up and lost, studies have shown that recovery is slower. Reefs can be lost forever.

2- before and after images demonstrating white coral after bleaching, and then algae-covered dead coral

Whats at stake here is the largest living structure in the world, and by far the largest coral reef system. The oft-repeated cliche is that it can be seen from space, which is not surprising given it stretches more than 2,300 km in length and, between its virtually 3,000 individual reefs, encompasses an region about the size of Germany. It is an underwater world of unimaginable scale.

But it is up shut that the Great Barrier Reef genuinely astounds. Among its water live a dizzying array of colourful plants and animals. With 1,600 species of fish, 130 types of sharks and lights, and more than 30 species of whales and dolphins, it is one of the most complex ecosystems on the planet.

It begins in the subtropical water of Hervey Bay in Queensland, about 200 km north of Brisbane. From there it stretchings the rest of the route up the eastern coast of Australia, stopping only off the coast of Papua New Guinea.

About 2 million people visit it per year and together they contribute virtually$ 6bn to the Australian economy.

Going back for millennia, Indigenous Australians have relied on the Great Barrier Reef. As the world emerged from the last ice age about 20,000 years ago and sea level began to rise, Indigenous Australians moved off the region that was once a floodplain and would have watched as todays Great Barrier Reef formed.

Today there are more than 70 Indigenous groups with a connection to the reef, many of whom depend on it for their livelihoods.

3 – before and after images demonstrating white coral after bleaching, and then algae-covered dead coral

Perhaps most disturbingly, what Marshall and Vevers have witnessed on Lizard Island is in no way unique. In the upper third of the 2,300 km reef its estimated that about half the coral is dead.

Surveys have revealed that 93% of the almost 3,000 individual reefs have been touched by bleaching, and almost a one-quarter 22% of coral over the entire Great Barrier Reef has been killed by this bleaching event. On many reefs around Lizard Island and further north, there is utter devastation.

Further south, the bleaching is less severe. Since tourists usually run diving and snorkelling in the middle and southern segments, there are plenty of spectacular corals for them to see there. But they shouldnt be fooled by that the reef is in the midst of a major environmental catastrophe.

Many scientists are now saying it is almost too late to save it. Strong and immediate action is required to alleviate water pollution and stop the underlying cause: climate change.

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