The Abbott government has pledged an extra $100 million as part of a long-term plan for the Great Barrier Reef that it hopes will prevent the international embarrassment of having the precious site declared officially "in danger" by the World Heritage Committee.

The funding, announced on Saturday, will go to landowners near the reef to come up with ideas on how to improve water quality as part of their land management practices.

Endangered: The Great Barrier Reef. Credit:Emma Brown (Supplied Image)

It was pledged as Prime Minister Tony Abbott and Environment Minister Greg Hunt launched the government's "Reef 2050 Long-Term Sustainability Plan", over-riding a draft version which was criticised for ignoring the effects of climate change on the important world heritage site.

The final version of the plan admits that "climate change is the most significant threat" to coral reefs worldwide but does not offer any specific strategy to tackle that threat in the Great Barrier Reef, beyond the government's pre-existing commitment to reduce Australia's emissions in line with international commitments through its "direct action" policy, a policy few climate scientists or economists have endorsed.