A new report has valued the Great Barrier Reef at $56 billion and warns of vast economic consequences for Australia unless more is done to protect it.
The Deloitte Access Economics report says the World Heritage-listed icon underpins 64,000 direct and indirect jobs, and contributes $6.4 billion to the national economy each year.
But without ramped-up protection efforts, it warns much of that could be at risk as the reef suffers from repeated mass coral bleaching events, poor water quality and climate change.
"The reef is critical to supporting economic activity and jobs in Australia. The livelihoods and businesses it supports across Australia far exceeds the numbers supported by many industries we would consider too big to fail," says the report, prepared for the Great Barrier Reef Foundation.
Of the 64,000 jobs linked to the reef, 39,000 are direct jobs - making the reef a bigger "employer" than the likes of Telstra, the Qantas Group, National Australia Bank, and the oil and gas extraction industry.
The report has been released amid a sustained campaign by environmental groups against Adani's new mega coal mine in Queensland, which they say will fuel the biggest threat to the reef's survival - climate change.
"There has never been a more critical time to understand precisely what the reef contributes and, therefore, what we stand to lose without it," says Dr John Schubert, chairman of the reef foundation that works to address environmental threats.
"This report makes it clear that the Great Barrier Reef is a treasure that is too big to fail. It is a call to action for us all - individuals, businesses, foundations and governments - to respond in equal measure to ensure that we don't fail our natural wonder."
Queensland's Environment Minister Steven Miles says the report is valuable as the state government fights for more federal assistance to safeguard the reef.
He says there's a discussion to be had about whether a levy that applies to reef visitors is "the right amount" or whether there are other ways to generate funds for reef protection.
"Certainly we could use more support from the federal government, it is a national asset," he told the Nine Network.
Deloitte says the $56 billion figure reflects the reef's economic, social and iconic value, with Australian tourists who've visited it accounting for $29 billion of that valuation.
But it ascribes almost as much - $24 billion - to Australians who are yet to see it, but value knowing that it exists.
A further $3 billion is put down to the value Australians see in being able to visit the reef's beaches, and boating and diving in reef waters.
The report was based on a range of previously published data, a new survey of more than 1,500 Australians and residents from 10 other countries, and consultations with stakeholders.