Great Barrier Reef Coral

Queensland scientists hope an underwater lab on the Great Barrier Reef will help them understand how growing seawater acidity caused by carbon emissions will affect coral survival.

Professor Ove Hoegh-Guldberg, from University of Queensland, said a team of scientists had set up the world-first experiment on a two-square-metre patch of the Great Barrier Reef just off Heron Island.

Prof Hoegh-Guldberg said the experiment simulated future levels of carbon emissions and looked at the effect on the reef's coral growth and ecosystems.

"The rise of carbon dioxide in the atmosphere has started to acidify the ocean, and over the past 10 years there's been an accumulation of laboratory studies," he said.

"But you really need to do these experiments in nature.

"The only trouble is, trying to do it is very tricky."

He said the scientists had set up four experimental chambers - two simulating future CO2 levels and two with control conditions.

"It's quite an engineering feat," he said.

"Electronics and power sources are on a float ... with mooring lines and anchors.

"There's a very long pipe and electronic cables going 100 metres into a laboratory into a computer.

"The computer regulates how much carbon is being added to the reef."

The equipment is automated but research assistants based at Heron Island must visit the float to check the equipment every three days.

The float was put in place last Friday.

"We have to make sure sea turtles haven't tipped things over," he said.

Prof Hoegh-Guldberg said scientists could use the research data to predict at what point the reef would fade away.

"The results will be really important ... so we can pull back from the brink so we don't lose the reef," he said.

"If you double CO2, the ability for coral to grow and calcify, making the skeletons ... reefs don't get repaired.

"The corals are disappearing at a rate of one or two per cent a year. That's a very low number, it seems, but if you multiply that by 20 years that's 40 per cent.

"These changes are subtle, but are absolutely devastating in the long-term.

"That's your grandchildren seeing the Great Barrier Reef disappear."

Up to one million species could disappear if the reef was eroded completely, and the tourist industry would also take a hit, Prof Hoegh Guldberg said.
The experiment will run for several years.

Great Barrier Reef