Damage to the Great Barrier Reef now 'entering uncharted territory'
Scientists in Australia have uncovered widespread damage to coral in the Great Barrier Reef, warning that "we are entering uncharted territory," after surveys showed consecutive years of bleaching for the first time.
Following aerial surveys this week between the coastal cities of Cairns and Townsville, researchers said warmer ocean temperatures had caused widespread bleaching. This followed severe bleaching along the 2,400km stretch of reefs last year - the worst on record - caused by warm sea temperatures in March and April.
"This is the first time we have ever seen bleaching in back-to-back summers," said Dr Neal Cantin, from the Australian Institute of Marine Science.
Typically, episodes of mass bleaching in the reef have been followed by several years of normal weather and ocean temperatures, which have allowed the coral to recover.
But scientists believe the sustained heat is believed to be reducing the tolerance of the coral. "Many coral species appear to be more susceptible to bleaching after more than 12 months of sustained above-average ocean temperatures," Dr Cantin said.
"We are now entering uncharted territory."
David Wachenfeld, from the federal government's Great Barrier Reef Marine Park Authority, said a warm summer in Australia had caused increasing heat stress since December.
"Regrettably, the temperatures have been high on the Great Barrier Reef this summer as well and unfortunately (we) are here to confirm . . . a mass coral bleaching event for the second consecutive year," he said.
The bleaching over the past two years has killed and endangered vast patches of coral which are up to 400-years-old, causing them to lose the vibrant colours which attract about two million tourists each year. (© Daily Telegraph London)