Acid Oceans to ‘Dissolve’ Coral Reefs in 30 years

By Stephen Leahy

BROOKLIN, Canada, Nov 12, 2007 (IPS)

Coral reefs face certain extinction in a few decades unless there are unprecedented reductions in carbon emissions, leading Australian scientists warn.

Corals around the world may be nothing but rubble before a child born today turns 30 years old, and almost certainly before they’re 50.

The reason? Rising carbon dioxide (CO2) levels in the atmosphere are turning the oceans acidic far faster than previously observed.

“It isn’t just the coral reefs which are affected. A large part of the plankton in the Southern Ocean, the coccolithophorids, are also affected,” said Malcolm McCulloch, an environmental research scientist at the Australian National University in Canberra.

[Update Sept 2010 – wide spread coral bleaching reportedWhat if our air was 30% more acidic like the Oceans? May be 120% more acidic by 2060]

“These (coccolithophorids) drive ocean productivity and are the base of the food web which supports krill, whales, tuna and our fisheries,” McCulloch said in a statement.

Plankton also play a vital role in removing carbon dioxide from the atmosphere and sequestering it in the deep ocean. Major declines in plankton mean atmospheric CO2 levels would rise far faster than the present forecasts and oceans would become even more acidic.

Recent research is showing that the ocean has become about one-third of a pH unit more acid over the past 50 years. This is roughly triple previous measurements.

“This is still early days for the research, and the trend is not uniform, but it certainly looks as if marine acidity is building up,” said McCulloch.


The oceans and the atmosphere are intimately connected — the quintessential yin and yang.

Changes in the atmosphere affect the oceans and vice-versa. Pump extra CO2 into the atmosphere from burning fossil fuels and some of that extra CO2 combines with carbonate ions in seawater, forming carbonic acid. The fact that CO2 is making the oceans more acid was established just three years ago. Scientists are still scrambling to determine the overall impacts.

“The effect of an acidifying ocean is that precious carbonate ions are removed,” says Ove Hoegh-Guldberg, a scientist at the Centre for Marine Studies at the University of Queensland, Australia.

“These ions are critical to the calcium carbonate production (calcification) of a range of marine organisms, including reef-building corals,” Hoegh-Guldberg told IPS.

Hoegh-Guldberg, McCulloch and more than 50 marine scientists attending a recent forum hosted by Australian Research Council Centre of Excellence for Coral Reef Studies have released a formal call to action, calling on “all societies and governments to immediately and substantially reduce greenhouse gas emissions”.

“Ocean acidification due to increased atmospheric CO2 is accelerating…Reducing CO2 emissions is the only way to prevent further damage to coral reefs,” they warn.

As carbon dioxide increases in the atmosphere, the concentration of carbonate ions declines, with the result that corals can no longer build reefs. The oceans have already absorbed nearly half of the fossil-fuel CO2 emitted into the atmosphere since pre-industrial times, causing a significant reduction in seawater pH.

“And with no reef framework, the habitat for an estimated million species is destroyed,” Hoegh-Guldberg said.

To see complete story click Between a Reef and a Hard Place 

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Related articles: Coral Reefs and Acid Oceans Series

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5 thoughts on “Acid Oceans to ‘Dissolve’ Coral Reefs in 30 years

  1. Ggood story, sad story. All the more sad as scinentists have recently discovered that coral have a kind of light-sensitive “eyesight” that allows them to “see” the full moon in spring/summer when they get ready to spawn, and they have been doing it — called on of the Earth’s most massive spawning events — for millions, billions of years, and now it might come to this……50 years down the road. Ouch!

  2. LINK:

    Key found to ”moonlight romance”

    An international team of Australian and Israeli researchers has
    discovered what could be the aphrodisiac for the biggest moonlight sex
    event on Earth.

    An ancient light-sensitive gene has been isolated by researchers from
    the ARC Centre of Excellence for Coral Reef Studies (CoECRS) that
    appears to act as a trigger for the annual mass spawning of corals
    across a third of a million square kilometres of Australia Great
    Barrier Reef, shortly after a full moon.

    The genes, known as a cryptochromes, occur in corals, insects, fish
    and mammals – including humans – and are primitive light-sensing
    pigment mechanisms which predate the evolution of eyes.

    In a new paper published in the international journal Science,
    the team, headed by Marie Curie Scholar Dr Oren Levy of CoECRS and the
    University of Queensland, reports its discovery that the Cry2 gene,
    stimulated by the faint blue light of the full moon, appears to play a
    central role in triggering the mass coral spawning event, one of
    nature’s wonders.

    Professor Ove Hoegh-Guldberg, who leads the University of Queensland
    laboratory in which the genes were discovered, said ”This is the key to
    one of the central mysteries of coral reefs. We have always wondered
    how corals without eyes can detect moonlight and get the precise hour
    of the right couple of days each year to spawn.”

    MORE (google)

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