An aerial survey of the northern Great Barrier Reef has shown that 95 per cent of the reefs are now severely bleached — far worse than previously thought.

Key points:

95 per cent of the Great Barrier Reef's northern reefs rated as severely bleached
Only 4 out of 520 reefs surveyed were found to be unaffected by bleaching
Third global coral bleaching event since 1998
Professor Terry Hughes, a coral reef expert based at James Cook University in Townsville who led the survey team, said the situation is now critical.

"This will change the Great Barrier Reef forever," Professor Hughes told 7.30.

"We're seeing huge levels of bleaching in the northern thousand-kilometre stretch of the Great Barrier Reef."

Of the 520 reefs he surveyed, only four showed no evidence of bleaching.

From Cairns to the Torres Strait, the once colourful ribbons of reef are a ghostly white.

"It's too early to tell precisely how many of the bleached coral will die, but judging from the extreme level even the most robust corals are snow white, I'd expect to see about half of those corals die in the coming month or so," Professor Hughes said.

Do you know more about this story? Email 7.30syd@your.abc.net.au
What is coral bleaching?

Occurs when abnormal environmental conditions cause coral to expel tiny photosynthetic algae, called zooxanthellae
Loss of colourful algae causes coral to turn white and "bleach".
Bleached coral can recover if the temperature drops and zooxanthellae are able to recolonise them, otherwise it may die
-Source: ARC Centre of Excellence
Coral bleaching is caused by abnormally high sea temperatures that kill the tiny marine algae essential to coral health.

This is the third global coral bleaching since 1998, and scientists have found no evidence of these disasters before the late 20th century.

"We have coral cores that provide 400 years of annual growth," explains Dr Neal Cantin from the Australian Institute of Marine Science.

"We don't see the signatures of bleaching in reduced growth following a bleaching event until the recent 1998/2000 events."

"There's good and bad news — the bottom three quarters of the reef is in strong condition," he said at the time.

"[But] as we head north of Lizard Island it becomes increasingly prone to bleaching."

The northern part of the Great Barrier Reef is the most pristine part of the marine park — and that is one possible glimmer of hope.

"On the bright side, it's more likely that these pristine reefs in the northern section will be better able to bounce back afterwards," Professor Hughes said.

"Nonetheless we're looking at 10-year recovery period, so this is a very severe blow."

'We're seeing climate change play out across our reefs'

Professor Justin Marshall, a reef scientist from the University of Queensland, said the reason for these bleaching events was clear.

"What we're seeing now is unequivocally to do with climate change," he told 7.30.

"The world has agreed, this is climate change, we're seeing climate change play out across our reefs."

2016 northern Great Barrier Reef coral survey
PHOTO: Coral bleaching is caused by abnormally high sea temperatures that kill the tiny marine algae essential to coral health. (ARC Centre of Excellence Coral Reef Studies)
I'm really angry that the government isn't listening to us, to the evidence we've been providing to them since 1998.
Reef scientist Justin Marshall
Professor Hughes said he is frustrated about the whole climate change debate.

"The government has not been listening to us for the past 20 years," he said.

"It has been inevitable that this bleaching event would happen, and now it has.

"We need to join the global community in reducing greenhouse gas emissions.

"For me, personally, it was devastating to look out of the chopper window and see reef after reef destroyed by bleaching.

"But really the emotion is not so much sadness as anger.

"I'm really angry that the government isn't listening to us, to the evidence we've been providing to them since 1998."

Mr Hunt told 7.30 that he was confident in the advice from the Great Barrier Reef Marine Park Authority — that the southern and central parts of the reef had so far escaped serious bleaching.

He said the Government had committed $2 billion over the next decade to protect the reef through initiatives such as improving water quality and removing the crown-of-thorns starfish.

A spokesperson for the Great Barrier Reef Marine Park Authority said it would be following up the aerial surveys with in-water surveys over the next two weeks to determine the true extent of the coral bleaching.

  I wonder what it would do to the billion dollar tourism industry which are based on the great barrier reef.   

innocentbystander. wrote on Mar 30^th, 2016 at 2:22pm:


The truth will set you free.

Svengali wrote on Mar 30^th, 2016 at 4:17pm:
You Asian guys blow coral reefs up to kill fish. Shame on you pin dick.

Mr Hammer wrote on Mar 30^th, 2016 at 4:32pm:


He's confused, 95% of his bum buddies have a bleached anus.

Its really sad news.  I wonder what it would do to the billion dollar tourism industry which are based on the great barrier reef.   

I wonder what would Andrew Bolt say now.  He did a show on it once, and invited his own panel of specialist.  One of them, apparent a marine biologist claim that ocean warming is in fact GOOD for the great barrier reef.  What a fraud he is.

Wow, look what El Nino, a natural event, has done to the water temperatures.

Did scientific american just describe the Industrial Era as having taken place just in the last 50 years?  I beleive they did. Along with believing that sensitive pH measurements of the ocean 200 years ago are pinpoint accurate.

too easy.

longweekend58 wrote on Mar 31^st, 2016 at 7:19am:



Then of course we had so many readings taken from all over the globe, that we could precisely determine the true global mean./sarc

longweekend58 wrote on Mar 31^st, 2016 at 11:29am:


Life expectancy at that time kept nature in balance. Now it is out of balance with overpopulation, deforestation, overgrazing and large holes everywhere.

longweekend58 wrote on Mar 31^st, 2016 at 11:29am:


but they lasted 50,000 years whilst leaving the environment in pristine condition. We will be lucky to last another 100 years with our paper money and fake economies

Mr Hammer wrote on Mar 31^st, 2016 at 6:15pm:


the abos have done f.ckall damage to the land in 50,000 years compared to the wholesale clearance by the whites in 200 years. Your comparison is absurd.

Mr Hammer wrote on Mar 31^st, 2016 at 7:27pm:


OK hammer head then give us electric cars instead of forcing 100 yo old fossil fool junk onto us

Mr Hammer wrote on Mar 31^st, 2016 at 9:17pm:



Don't forget your recharging points. Especially for long trips.

Mr Hammer wrote on Mar 31^st, 2016 at 9:17pm:


No I don't have respect for australia. It's a country run by f.ckwitts for f.ckwitts.

Mr Hammer wrote on Mar 31^st, 2016 at 9:52pm:
Geez I hope you don't live here.

Mr Hammer wrote on Mar 31^st, 2016 at 9:58pm:

I couldn't bite the hand that feeds me like you do. What a pity you don't  go somewhere else.

Sir lastnail wrote on Mar 31^st, 2016 at 6:31pm:
Well if you have such disrespect for current Australia then why don't you sell up the modern conveniences, car, home, stop getting medical treatment, don't eat the food those environmental vandals the farmers grow etc etc and go f ark off  into the bush so you don't look like a stinking hypocrite.

John_Taverner wrote on Mar 31^st, 2016 at 8:37am:



But changes in water temperature has been postulated as a cause of bleaching.

What you appear to be saying is that coral bleaching is causing temperature change.

lee wrote on Mar 31^st, 2016 at 9:25pm:




Can't you just use an extra long extension cord?

95% bleached? Rubbish

I watched a program the other day that stated the northern parts of the reef were in good order & the most pristene.

And they will regenerate the southern bleach affected areas

You can fool some of the people all of the time.

95% bleached? Rubbish

I watched a program the other day that stated the northern parts of the reef were in good order & the most pristene.

And they will regenerate the southern bleach affected areas

Gnads wrote on Apr 1^st, 2016 at 8:41am:


Gnads, the perennial dupe.

You can fool some of the people all of the time.

it is the THIRD bleaching even since 98 which means... tada...

IT HAS RECOVERED THREE TIMES IN THE PAST 20 years.

coral bleaching is a feature of coral in the first place. 

firstly the water HASNT risen byt more than a few centimetres. It HASNT warmed by more than a few hundreths of a degree.. perhaps.  and PH levels havent changed at all.

nothing new to see here.

One poster talked about how China blow up the coral for fish.   But with mass bleaching event like this, scale wise its MUCH MUCH worse than blowing up the coral.   It depletes fish stocks, and basically negates all the good work that we have done in Australia in terms of fishing management, and with that severe economic repercussions. 

BatteriesNotIncluded wrote on Mar 31^st, 2016 at 11:19pm:
Haven't you got an internet connection to fix numptoid?

John_Taverner wrote on Apr 1^st, 2016 at 1:05pm:



What does a precipitation map of the land area say of SST's?

On Thursday the ABC revealed secret modelling that showed it could cost up to $16 billion to meet water quality targets over the next 10 years just to meet water quality targets for the reef.

“It is highly likely that two degrees of warming (above pre-industrial rates) would destroy the Great Barrier Reef as we know it,” Professor Will Steffen of the Climate Council told news.com.au.

In April, a group of 56 scientists signed an open letter calling for Australia to block new coal mines and phase out coal-fired power stations.

Economist Stephen Bartos of Pegasus Economics told news.com.au that if Australia pulled out of coal abruptly there would be a short term impact on growth but in the longer term moving away from mining would actually be a good thing.

Surprise surprise surprise

"Activist scientists and lobby groups have distorted surveys, maps and data to misrepresent the extent and impact of coral bleaching on the Great Barrier Reef, ­according to the chairman of the Great Barrier Reef Marine Park Authority, Russell Reichelt."


http://www.theaustralian.com.au/news/nation/great-barrier-reef-scientists-exagge...

This opinion from Russell Reichelt, the same chairman of the Great Barrier Reef Authority, who approved the proposal for dredge spoil from the Abbott Point coal port expansion to be dumped on the reef?

Laugh till you cry wrote on Jun 4^th, 2016 at 10:55am:


You obviously missed this bit

A full survey of the reef ­released yesterday by the author­ity and the Australian Institute of Marine ­Science said 75 per cent of the reef would escape unscathed.

So I suppose AIMS is in on it too, damn these non-activist scientists!

mitasol wrote on Jun 4^th, 2016 at 12:50pm:


Were they paid for that report by the government?

mitasol wrote on Jun 4^th, 2016 at 1:49pm:


Liberal voters?