New plans for the Great Barrier Reef Marine Park ban commercial fishermen from a third of the giant coral network off Australia's northeast coast and tightens restrictions on shipping through the delicate ecosystem.
Environment Minister David Kemp described the plan as a "historic and visionary" initiative that would help protect the reef - considered by scientists to be the world's largest living organism - from the ravages of pollution and over-fishing.
Conservationists welcomed the move, but warned that threats to the reef from climate change and land-based pollution still needed to be addressed.
The plan expands "high protection zones" from 4.6% of the Great Barrier Reef park to covering 33.3% of its area. These so-called "green zones" would be off-limits to fishermen, with only research and tourism allowed. Restrictions on shipping in reef areas were also tightened.
In response to protests from commercial fishing interests, the government last month agreed to a compensation package for those affected. Amounts have yet to be decided.
The reef, a world heritage listed natural wonder covers more than 345,000 sqkm and comprises 2900 coral reefs, 900 islands and 1500 fish species.
It is Australia's number one tourist destination, attracting a million visitors a year and generating revenues of more than $2.3 billion, Australian ($1.7 billion, US).
Scientists have warned that the reef is under increasing threat from coral bleaching linked to global warming, pollution from shipping, over-fishing and damage caused by chemical run-off from coastal agriculture.
The reef is home to about 1500
species of fish
Kemp said the government's zoning plan, submitted on Wednesday to parliament, would help tackle such threats by creating the "largest network of protected marine areas in the world".
The initiative is expected to pass through parliament by late March and take effect in mid-2004, Kemp's spokeswoman said.
The tourism industry and conservationists generally praised the plan, with WWF Australia describing it as a stunning achievement and a win for all Australians.
"The new network of marine sanctuaries will result in very real and tangible benefits for the health of the Reef and its stunning wildlife," said WWF campaigner Imogen Zethoven.
Fishing industry officials for their part complained that the new Green Zones were too extensive.
Industry officials have estimated the plan will cost commercial fishing and prawn farming industries about $38 million, Australian ($28 million, US) a year.