Study: Coral reefs like 'junk food'

TOWNSVILLE, Australia, March 26 (UPI) -- Australian scientists have discovered coral reefs have an addiction to "junk food" and order symbiotic algae to produce it.

James Cook University researchers said the symbiosis between coral, a primitive animal, and zooxanthellae -- tiny one-celled plants -- has not only built the largest living organism on the planet, the Great Barrier Reef, but also underpins the economies of many tropical nations.

The issue of whether the partnership is robust enough to withstand climate change is driving a worldwide scientific effort to decipher how corals and their symbiotic algae communicate, said JCU Professor David Yellowlees.

"It's an incredibly intricate relationship in which the corals feed the algae and try to control their diet, and the algae in turn use sunlight to produce 'junk food' -- carbohydrates and fats -- for the corals to consume," said Yellowlees. "Where it all breaks down is when heated water lingers over the reef and the corals expel the algae and then begin to slowly starve to death.

"This is the bleaching phenomenon Australians are by now so familiar with, and which is such a feature of global warming."

The research is to appear in the journal Plant Cell and Environment.