Great Barrier Reef faces rapid coral loss

2012-10-01 22:19

Singapore - The world's largest coral reef - under threat from Australia's surging coal and gas shipments, climate change and a destructive starfish - is declining faster than ever and coral cover could fall to just 5% in the next decade, a study shows.

Researchers from the Australian Institute of Marine Science (AIMS) in the northeastern city of Townsville say Australia's Great Barrier Reef has lost half of its coral in little more than a generation. And the pace of damage has picked up since 2006.

Globally, reefs are being assailed by myriad threats, particularly rising sea temperatures, increased ocean acidity and more powerful storms, but the threat to the Great Barrier Reef is even more pronounced, the AIMS study published on Tuesday found.

"In terms of geographic scale and the extent of the decline, it is unprecedented anywhere in the world," AIMS chief John Gunn told Reuters.

AIMS scientists studied data from more than 200 individual reefs off the Queensland coast covering the period 1985-2012. They found cyclone damage caused nearly half the losses, crown-of-thorns starfish more than 40% and coral bleaching from spikes in sea temperatures 10%.

The starfish are native and prey on the reefs. But plagues are occurring much more frequently.

Ordinarily, reefs can recover within 10 to 20 years from storms, bleachings or starfish attacks but climate change impacts slow this down. Rising ocean acidification caused by seas absorbing more carbon dioxide is disrupting the ability of corals to build their calcium carbonate structures. Hotter seas stress corals still further.

Greens say the 2 000km long reef ecosystem, the centre-piece of a multi-billion tourism industry, also faces a growing threat from shipping driven by the planned expansion of coal and liquefied natural gas projects.

Those concerns have put pressure on the authorities to figure out how to protect the fragile reef.

Falling fast

The researchers say the pace of coral loss has increased since 2006 and if the trend continues, coral cover could halve again by 2022, with the southern and central areas most affected.

Between 1985 and 2012, coral cover of the reef area fell from 28% to 13.8%.

"Coral cover on the reef is consistently declining, and without intervention, it will likely fall to 5 to 10% within the next 10 years," say the researchers in the study published in the Proceedings of the National Academy of Sciences journal. They called for tougher curbs on greenhouse gas emissions as a crucial way to stem the loss.

Shipping and new ports on the Queensland coast are another major threat, Greenpeace says.

Coal is one of Australia's top export earners and the state of Queensland is the country's largest coal-producer. It also has a rapidly growing coal-seam gas industry for LNG exports.

Earlier this year, Greenpeace estimated port expansion could more than triple Queensland's coal export capacity by 2020 from 257 million tonnes now. That would mean as many as 10 000 coal ships per year could make their way through the Great Barrier Reef area by 2020, up 480% from 1 722 ships in 2011, according to the group.

The Queensland and national governments, which jointly manage the reef, have launched a major review of managing the risks facing the Unesco-listed reef and its surrounding marine area. The review will look at managing the threats from increased shipping to urban development.

Gunn said better management was all about buying time and improving the reef's resilience to climate change. A key area was improving water quality from rivers flowing into the reef area, with studies suggesting fertiliser-rich waters help the crown-of-thorns starfish larvae rapidly multiply.

  • amanda.victor.92 - 2012-10-02 02:40

    Ohh, another scare mongering story when in fact the reefs are doing just fine and even increasing. I'm so sick of this climate change rubbish.

      robin.stobbs.9 - 2012-10-02 08:34

      Right! @MemeMan; Clifton is not quite the same as the Barrier Reef and your observations, though probably quite valid, are subjective at best. I too noticed reefs being taken over by sea urchins with fish species, gastropod molluscs and coral growth declining ...... that was in Kenya in the 1950s and early 1960s! It is well known (and published) fact that storms, floods and heat waves are no more prolific nor worse than they have been for centuries. Have you looked at the effects of the el Niño and la Niñna lately - this has more provable effect on weather patterns than all the climate change hype. I personally know some researchers working on the Barrier Reef and their finding over the past 20 years do not match those put out by the alarmists there. As for the Crown-of-Thorns? Well there was this plague of them over the entire Pacific region back in the early 1970s and the alarmist fraternity even had divers going around injecting formalin into them in an attempt at controlling the plague; which they all put down to increasing marine pollution.(See Theo Brown and Keith Willey, "Crown of Thorns: the death of the Great Barrier reef?"). Then around ten years later two scientists boring test cores through the Barrier Reef came across evidence of sporadic Crown-of-Thorns infestations going back some thousand years (the extent of their drilling) - and some were of a magnitude a hundred times or more what had been experienced in the 1970s plague.

      stirrer.stirrer - 2012-10-02 11:00

      100% correct, Robin. Cycles, cycles, cycles. Some so-called "scientists" just don't get it.

      stirrer.stirrer - 2012-10-02 12:08

      MemeMan, I find your obsession with religion quite disturbing. Scepticism about AGW has nothing to do with religion, except maybe in your own mind. As I said, I don't deny climate change, but I have a BIG problem with alarmists trying to stop it. It's like trying to stop planet from turning - it just won't happen. We should rather focus our energies on how we are going to adapt to climate change, and I've not seen anything to that effect yet, just more and more studies trying to prove that the ice caps are melting, the sea is heating up, etc. OK, we get it. Now how will we adapt to it?

      ernst.j.joubert - 2012-10-02 15:07

      @MemeMan: As usual, very well said.

  • Timothy David Leslie - 2012-10-02 14:27

    so robin what are you saying? that these scientists are making all of this up? for what..? there observations are invalid how? you sound like an intelligent scientist yourself, please explain to me how you know better than the leading professors at the world's leading universities around the world who all proclaim that evidence for anthropogenic climate change is undeniable? sometimes you need to see the light and realise that there are better qualified, more intelligent people out there who's life's work and their findings is just a little bit more respectable than your inferior opinion and pitiable opinion.

      ernst.j.joubert - 2012-10-02 15:07

      @Timothy: Exactly.

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