Releasing the draft proposal, Environment Minister David Kemp said the plan would create the largest network of protected marine areas in the world as the government tried to balance its duty to protect the environment with its commitments to the fishing and tourism industries.

"The Great Barrier Reef is the largest world heritage area in the world and this new zoning system will establish a new international standard for the protection of reefs," Kemp said on public radio. "The reef is Australia's greatest natural icon."

Marine scientists have long warned the government of the imminent danger if a combination of threats to the reef weren't checked.

"The reef is under pressure: we're loving it to death," Bruce Kingston, education officer with the Great Barrier Reef Marine Park Authority, told AFP.

"There has to be some significant change and I think the levels of government are now realising that."

He said the greatest threat was sediment and chemical-laden run-off from coastal towns and farms.

Excess nutrients kill off the tiny organisms which create new coral and provide food for the parasitic crown of thorns starfish, which eats coral and have already destroyed large areas of the reef.

Climate change is a threat which is difficult to tackle. Cutting harmful emissions is all that can be done to slow coral bleaching while recreational and commercial fishers threaten the reef through overfishing.

Kemp's plan would expand so-called "high protection zones" from 4.6 percent to around 30 percent of the reef, which covers more than 345,000 square kilometers (133,000 sq miles) off Australia's northeast coast.

These so-called "green zones" areas would be off-limits to fishermen and shipping, with only research and tourism activities allowed.

Other proposals include increasing by one-third the area designated "no-go" zones closed to all users except researchers with permits, and cutting from 50 percent to 34 percent the areas of the reef accessible to prawn trawling.

The draft plan was a result of more than 10,000 submissions from local residents, commercial and recreational fishing groups, tourist operators and environmental groups.

Scientists consider the Great Barrier Reef, which consists of 2,900 coral reefs, 900 islands and 1,500 fish species, the world's largest living organism.

It is also Australia's number one tourist destination, attracting one million visitors annually to view the reef's spectacular corals and tropical fish while scuba diving, snorkelling and cruising the pristine waters.

A spokesman for Tourism Taskforce told AFP he welcomed the plan and recognised his role in protecting the reef.

"The tourism industry is becoming more environmentally aware -- and selfishly their commercial future depends on them maintaining those areas in perpetuity."

But commercial fishing groups said the plan would result in severe job losses.

"There's going to be a substantial impact on industry," said Queensland Seafood Industry Association chief Duncan Souter.

Environmental groups generally praised the plan as a step in the right direction.

But the leader of the Greens party, Senator Bob Brown, said the increase in protected reef areas needed to be backed up with action on land clearing and global warming, which both threaten the coral reefs.

SPACE.WIRE