Giant cooling rotors may breathe life into Barrier Reef

AUSTRALIA: Huge rotating pumps will be installed in the Coral Sea in an attempt to save Australia’s Great Barrier Reef from climate change by cooling it.

Eight of the solar-powered devices will be placed over a section of the reef near Cairns in Australia’s far north.

It is hoped they can ward off bleaching that has either damaged or killed coral on swathes of the 2300km-long reef.

The machines, mounted on pontoons, use large rotating pumps to draw cooler water from 30 metres below the surface and propel it over the coral to recreate cold currents around the reef that have been weakened by warming seas. The cooler currents reduce damage and help the reef recover.

Four serious bleaching events over the past 20 years have affected more than half the reef.

Tropical coral reefs can tolerate only small temperature changes. Bleaching of the coral kills the algae that live inside it. The coral then becomes transparent. Its growth is stunted, and it can die if temperatures do not drop back to normal levels.

‘‘We’re hoping that turning on the fan when it’s really hot will help keep the corals more comfortable,’’ Sheriden Morris, head of the Reef and Rainforest Research Centre in Cairns, said.

She said it was vital measures were taken to save the reef now. The pumps will be placed over a square kilometre, and the project will be expanded if it is a success.

‘‘This intervention will never save the whole of the Great Barrier Reef,’’ Morris said. ‘‘But it will be important for some of our particularly valuable tourist sites, which [provide] 64,000 jobs.’’