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CORAL BLEACHED FOR two consecutive years at Australia’s Great Barrier Reef has “zero prospect” of recovery, scientists warned today, as they confirmed the site has again been hit by warming sea temperatures.
Researchers said last month they were detecting another round of mass bleaching this year after a severe event in 2016, and their fears were confirmed after aerial surveys of the entire 2,300-kilometre long bio-diverse reef.
Last year, the northern areas of the World Heritage-listed area were hardest hit, with the middle-third now experiencing the worst effects.
“Bleached corals are not necessarily dead corals, but in the severe central region we anticipate high levels of coral loss,” said James Kerry, a marine biologist at James Cook University who led the aerial surveys.
It takes at least a decade for a full recovery of even the fastest growing corals, so mass bleaching events 12 months apart offer zero prospect of recovery for reefs that were damaged in 2016.
It is the fourth time coral bleaching – where stressed corals expel the algae that live in their tissue and provide them with food – has hit the reef after previous events in 1998 and 2002.
Record temperatures
“The combined impact of this back-to-back bleaching stretches for 1,500 kilometres, leaving only the southern third unscathed,” said Terry Hughes, head of the Centre of Excellence for Coral Reef Studies, also at James Cook University.
The bleaching is caused by record-breaking temperatures driven by global warming.
“This year, 2017, we are seeing mass bleaching, even without the assistance of El Nino conditions,” he added, referring to the natural climate cycle in the Pacific Ocean.
The Barrier Reef is already under pressure from farming run-off, development and the crown-of-thorns starfish.
It was also recently hammered by category four Cyclone Debbie, which barrelled through the region last month, mostly affecting southern parts around the Whitsunday islands which largely escaped the bleaching.
The extent of the destruction wrought by Debbie is not yet known, although scientists have said damage could range from minor to severe.
Queensland Parks and Wildlife Service and the Great Barrier Reef Marine Park Authority began a study last week to determine how extensive it might be and have already found extensive pulverised coral at popular snorkelling spots.
“The feedback that’s coming back is the more sheltered areas have come out a bit better, but they all seem to have suffered some form of damage,” Association of Marine Park Tourism Operators’ Brendon Robinson told the Australian Broadcasting Corporation.
The Whitsundays is one of the reef’s tourist hotspots, attracting more than 40% of total visitors to the iconic marine ecosystem.
Multiple impacts
Hughes warned rising temperatures could see more bleaching events.
“Clearly the reef is struggling with multiple impacts. Without a doubt the most pressing of these is global warming,” he said.
“As temperatures continue to rise the corals will experience more and more of these events. One degree Celsius of warming so far has already caused four events in the past 19 years.
“Ultimately, we need to cut carbon emissions, and the window to do so is rapidly closing.”
The world’s nations agreed in Paris in 2015 to limit average warming to two degrees Celsius over pre-industrial levels, by curbing fossil fuel burning.
Canberra in 2015 narrowly avoided UNESCO putting the reef on its endangered list, and has committed more than Aus$2.0 billion to protect it over the next decade.
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Beyond sad and shocking. I wonder what will be left for my kids.
@john Appleseed: nature always finds a way to bounce back. The coral that was safe in the protected areas will once again spread.
If humans left this earth in 30 years the amount of vegetation that would grow would be astounding. 100 years (just a blip on earth existence) you would have trees growing through houses, most buildings (out of city’s) would be ruins.
@Lily: it grows 20mm a year and with 1,500 kilometres of it bleached (dead) it will take the Great Barrier Reef up to 10,000 years to recover if the bleaching stopped today but it’s not stopping it’s accelerating. So keep telling yourself everything is ok and your grand kids will consider you a fool.
@Boganity:
10,000 is still a blip in earths existence.
There are many cycles the earth has gone through. It always comes back. Even after a meteor wiped out the dinosaurs. A cyclone and a bit of hot water killing off some coral, the bigger picture is that nature trumps natural disasters and will always win.
Yep I won’t be around to see it. In our years it will take a long time. But really in the scheme of things it’s only a blink.
@Lily: also, talk of nature recovering assumes humans are not here. I sometimes wonder if this is the reason we have never met aliens. Perhaps all civilizations ultimately consume the planets and never get advanced enough in time to escape the planet they have consumed.
Short term thinking will cause long term and irreversible adverse consequences.,
Keep buying the new cars folks. Burn the atmosphere up for your own vanity.
@Veron Skvortsova: Newer cars have better emissions, efficiency and may even be electric.
@Jimmy Ireland: you clearly haven’t thought of the fact that making this new car uses a massive amount of energy and resources.
@Sean Claffey: that is a good point. Driving an old petrol engined car and not replacing it may actually be much less environmentally damaging. Old diesels had the disadvantage of NOX emissions.
I hate to break it to you lads, but old cars stop working eventually, and new ones have t9 be made to replace them, even if you just keep buying the old ones.
@Neal, not Neil.: I don’t know if you’ve noticed but people tend to buy new instead of repairing these days, not just cars but everything. And people often replace their old working car with a new car simply because they want something new.
Not to mention the amount of damage and pollution tourism brings on top of that.
@John Cahill: tourists are only allowed access to a tiny fraction of the reef and then only under supervision
The bleaching of the coral reefs is an early sign or eventual environmental disaster for human beings.
Ozzies have a horrific record of protecting the environment and combatting climate change.
You reap what you sow.
Very sad this
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