‘It’s
a depressing sight’: climate change unleashes ghostly death on
Great Barrier Reef
Months
after the worst coral bleaching event to hit the reef, Australian
conservationist Tim Flannery returns to a tourism hot spot 50km
north-east of Port Douglas to witness the destruction wrought by a
warming planet
Michael Slezak
Wednesday 21
September 2016 21.19 BST
John Rumney says
that just a year ago, this particular spot was once the most stunning
coral garden on the entire Great Barrier Reef. If a film crew said it
wanted to get a cliche shot of the reef with its mind-boggling
richness of coral and fish species, this was where he took them.
Now he’s taking us
there to see the destruction wrought by climate change. He says the
fact this reef was used in so many films and magazines means it’s a
perfect location to see the effects of the recent bleaching event.
He tells us he would
regularly describe the location as having “more than 100% coral
cover”. “It was growing on top of each other and underneath. It
was just magnificent,” says Rumney, a veteran reef tourism
operator, who helped pioneer ecotourism on the reef, and is now
establishing a privately funded non-profit research enterprise, Great
Barrier Reef Legacy.
“So we have a
great baseline of what it was like. And it was absolutely fantastic,”
says Rumney. “So anything that is damaged is directly proportional
to this year’s bleaching. It’s not like it’s 50% dead and then
you had bleaching so you don’t know what is old and new.”
Much has been
written about the devastating global coral bleaching event that has
snaked its way around the world since 2014, and which touched 93% of
reefs on the Great Barrier Reef this year.
Surveys of the full
impact suggest the worst impacts were in the remote northern third of
the reef, far from where tourists regularly go. While almost a
quarter of coral has been killed on the Great Barrier Reef, it has
been concentrated in the area north of Port Douglas.
Despite that, the
effects on this reef just 50km north-east of Port Douglas – the
most popular launching point for reef tourism – have been severe.
Guardian Australia
is here with the Climate Council, which visited this reef at the peak
of the bleaching, in May, and has come back now to see how much has
recovered.
Snorkelling on the
outer reef where the water is crystal clear, it’s obvious what a
vibrant reef it would have been just a few months ago.
While the seafloor
is almost completely covered by coral, much of it is dead, covered
with algae and starting to lose its structure. There are few of the
fish that use coral as cover, but plenty of parrot fish and others
that feed on the algae that is starting to cover the reef.
Tim Flannery, a
prominent conservationist and a Climate Council councillor, visited
this reef in May. “The coral wasn’t dead but it was severely
damaged,” he says.
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Although a proper
study would be needed to make a full estimate of how much was
bleached back then, Rumney and Flannery say it was in the order of
80% to 90%.
As would be expected
in all but the most extreme marine heatwaves, most of the coral found
bleached in May recovered.
Coral bleaches when
the water around it is too warm for too long. The coral polyps get
stressed and spit out the algae that lives inside it. Without the
colourful algae, the coral flesh becomes transparent, revealing the
stark white skeleton beneath.
Because the algae
provides the coral with 90% of its energy, it begins to starve.
Unless the ocean temperature return to normal within a month or two,
the coral dies and gets taken over by a blanket of seaweed.
Now, upon Flannery’s
return, the state of this particular reef has advanced to the point
where it appears about 30% of the coral has died.
Emerging from the
water, Lesley Hughes, another of the Climate Council’s councillors
and an ecologist from Macquarie University, says it’s distressing
to see so much death on the reef.
The Great Barrier
Reef: a catastrophe laid bare
Read more
Alongside the dead
coral and algae, there appears to be an outbreak of the coral-eating
crown-of-thorns starfish. Under dead, broken coral, groups of
starfish congregate, munching on the remaining live coral.
“So all up it’s
a pretty depressing site down there actually,” Hughes says.
The bleaching event
was caused by unusually warm water. It was spurred on by El Niño,
but the unprecedented level of heat was a clear sign the primary
cause was global warming.
“You’d be easily
fooled into thinking this was some sort of natural event,” says
Flannery. “But it has been caused by people. It’s the burden of
greenhouse gases in the atmosphere causing these unprecedented
underwater heatwaves that these ecosystems have just never
experienced before and just have no capacity to absorb. The coral
just dies.”
For Flannery, the
dead coral is a stark reminder of the well-known response that is
needed to climate change.
“If it was up to
me and I was the Australian government looking at the loss of this
asset, I would be announcing a plan to close down all of our
coal-fired power plants over a given period of time, shift to clean
energy, and do whatever it takes in the transport sector and so forth
to make that transition,” he says.
“And then go to
the international community and say ‘look, this global asset is in
real danger, here’s what we’ve done to try and secure it, please
join us to do your bit as well’.”
To head back to Port
Douglas from the outer reef, we weave through the ribbons of reef
that link together for hundreds of kilometres along the Queensland
coast. As we approach the shore, a ship in the distance gets larger
and larger and we slowly realise it’s a coal tanker.
Having collected its
coal from one of the ports that dot the Great Barrier Reef, it’s
delivering it to somewhere in the world – perhaps India or China –
where it will be burned, create more greenhouse gases and further
warm the atmosphere, making the next coral bleaching more likely.
• Michael Slezak
and Josh Wall were guests of the Climate Council
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