Sydney: The long-term outlook for Australia's Great Barrier Reef was downgraded to "very poor" for the first time Friday by the official agency charged with managing the world heritage site. In its latest five-yearly report on the health of the world's largest coral reef, the Great Barrier Reef Marine Park Authority singled out rising sea temperatures due to climate change as the biggest threat to the giant organism.

"The significant and large-scale impacts from record-breaking sea surface temperatures have resulted in coral reef habitat transitioning from poor to very poor condition," the government agency said. It said "strong and effective management actions are urgent at global, regional and local scales" to rescue the 2,300-kilometre (1,400-mile) reef, a UNESCO World Heritage site.