Great Barrier Reef.

National treasure: The Great Barrier Reef's unique beauty and immense economic value means it's protection is of vital importance to each of the major parties. Photo: Poseidon Cruises.

Judging by the positions taken by all major parties contesting the federal election, everyone wants to save the Great Barrier Reef. Even those unmoved by the beauty of the coral labyrinths and marine life recognise the huge economic benefit the reef brings, which includes $5 billion in cash and 63,000 permanent jobs as a direct result of tourism and research.

Coral cover has shrunk by half since 1985, inshore reefs have declined 34 per cent in the last eight years, and outbreaks of crown-of-thorns starfish are becoming common, fed by farm runoff from the Queensland coast.

Crown of thorns starfish.

Enemy mine: A crown-of-thorns starfish on the reef. Photo: J.H. Harding.

There are wider problems than just local pollution, or the bombs dropped in the marine park by a wayward US aircraft last month.

The Great Barrier Reef Marine Park Authority says unequivocally that ''in the long-term, ocean acidification is likely to be the most significant impact of a changing climate on the Great Barrier Reef ecosystem''. A CSIRO report last year said acidification was already affecting biological systems, with reef corals likely to experience slower growth.

The Coalition is apparently poised to unveil its ''Reef 2050'' policy, though the deadline for its release has been pushed back before, and few details have been exposed to public scrutiny

''The plan will address the threat posed by the crown-of-thorns, reduce run-off, improve water quality and protect the turtle and dugong population,'' the party's website says.

One fragment was announced last week, with $5 million promised to help control illegal turtle and dugong poaching, which is carried out in some communities in Queensland and the Torres Strait.

''These actions are not supported by the indigenous elders and we will work with them to stop this illegal practice, which is impacting on dugong and turtle numbers and harming local tourism operations,'' the Coalition's environment spokesman, Greg Hunt, said.

The federal government's plan, developed in partnership with the states, is necessarily more public and, at this stage, more comprehensive. A decision on the reef's heritage status is to be handed down in the next parliamentary term, and international body UNESCO has said it is on the brink of being reclassified as a ''World Heritage site in danger''.

The government has allocated $375 million between 2013 and 2018 to reduce run-off from farms and improve water quality.

Elements of the plan have been in operation for several years and are showing some solid results, with pesticide run-offs significantly cut and some other chemicals and fertilisers reduced. However, some target dates set for pollution reduction were quietly revised backwards when they were deemed impossible to meet.

''We continue to work hard, in difficult circumstances, to meet our targets,'' Environment Minister Mark Butler said last month.

The Greens have pledged to push for stronger protection, especially around dredging zones for new coal and gas ports, setting ''no-go'' zones'' for some regions. In total, the party's ''reef protection package'' would cost $176 million in addition to current spending, and increase efforts to cut chemical run-off, and fund more research and long-term planning.