Australia Wednesday gave Rio Tinto the go-ahead for a controversial Aus$1.3 billion (US$1.3 billion) bauxite mine project in a decision environmentalists blasted as "vandalism on a grand scale".

After more than a year of delays, Environment Minister Tony Burke approved Rio Tinto Alcan's South of Embley bauxite mine and port development in western Cape York, a wilderness area in northeastern Australia.

Burke slapped 76 conditions on the project, including on shipping movements through the Great Barrier Reef and steps to protect endangered species such as turtles, dugongs and dolphins.

"My decision comes after a rigorous environmental assessment, and the conditions I have placed on the project will ensure that the region is protected," he said.

The project includes building a power station, processing plant, warehouses and workshops, in addition to barge, ferry and ship-loading facilities to extend the life of an existing bauxite mine in the area for a further 40 years.

"Respect for the environment is central to the way we operate, and we will ensure all the conditions for the construction and operation of the project are met," said Pat Fiore, chief executive of bauxite at Rio Tinto Alcan, an arm of Rio Tinto.

But environmentalists said Burke had approved the single biggest land clearing project in Cape York's history, claiming it would wipe out 30,000 hectares (74,000 acres) of a landscape identified as being of World Heritage standard.

They also said it would mean hundreds more ships crossing the Great Barrier Reef.

"This mine will result in environmental vandalism on a grand scale," said Tim Seelig, Queensland campaign manager for the Wilderness Society.

The approval came just days after the United Nations warned that the Great Barrier Reef's world heritage status could be downgraded in 2014 due to rampant coastal development and water quality issues.

"Management plans and monitoring programmes don't change the fact that Labor is letting Cape York be strip mined and allowing even more massive ships to crash through the Great Barrier Reef," said Australian Greens environment spokeswoman Larissa Waters.

Australia is riding an unprecedented wave of resources investment due to booming demand from Asia, with hundreds of billions of dollars' worth of resource projects in the pipeline.