Australia's Great Barrier Reef - the world's largest living organism - is under a major threat from global warming and coastal development and recent report says the chances of survival are "poor".

Though the World Heritage-protected site is in a better position than most other reefs around the world, the risk of its destruction is building.

"Even with the recent management initiatives to improve resilience, the overall outlook for the Great Barrier Reef is poor and catastrophic damage to the ecosystem may not be averted," a government reef body said in the report.

The report, which is done every five years to determine the health of the reef, found that climate change, declining water quality from coastal excess, development and illegal fishing were the greatest dangers to the reef.

The study reported that the Great Barrier Reef could be "functionally extinct" within decades, and face deadly coral bleaching as an annual occurrence by 2030.

The reef spreads out over 345,000 square km off Australia's east coast. It was one of the world's most diverse and extraordinary ecosystems in the world, housing almost all marine species in large populations.

But the report found that some important species, like dugongs, marine turtles, seabirds, black teatfish and some sharks had declined significantly, and coral diseases and pest outbreaks like crown-of-thorns starfish seemed to be increasing and becoming more serious.

"We cannot sit back and let the world's largest and most iconic reef system die on our watch," said WWF reef campaigner Nick Heath.

[via Reuters]