Native Australian bushland continues to be cleared at massive scale for cattle grazing, threatening the Great Barrier Reef and climate targets, despite federal efforts to rein in the practice and major supermarkets committing to stripping beef raised on cleared land from their supply chains.

A team of citizen scientists studied satellite imagery covering 10 million hectares of land and identified 30,000 hectares of forest and woodland that had been bulldozed on 150 sites, which were later verified by Australian Conservation Foundation environmental investigators. The ACF has reported 34 of these cases to the National Environmental Protection Agency, which began operations in July.

ACF chief executive Adam Bandt called on the government to use the new agency to crackdown on any land clearing found to be illegal.

“I think the fundamental problem is corporations are killing koalas and wrecking the reef to make burger patties,” he said. “The corporate food system is broken, and the new laws give us a chance to fix it so that the way we grow food restores nature.”

Australia remains the only wealthy country that still clears native forests for agriculture, and the extent of the clearing is even greater than the amount of land cleared in Indonesia for palm oil, said the lead author of the study, Nathaniel Pelle.

Pelle said the study was only a snapshot of clearing conducted, and that the total area cleared was likely to be between 250,000 and 300,000 hectares. The study found 11 instances of clearing within the catchment of the Great Barrier Reef, in some cases along river and creek lines in apparent contravention of environmental laws.

Land clearing is viewed as second only to global warming as a threat to the reef, as it causes sediment and nutrient runoff that can choke chorals and promote algae growth and crown of thorn starfish outbreaks.

It found most clearing was conducted in Queensland and NSW, and the vast majority for beef grazing, with bulldozed forests including habitat for threatened species such as koalas, quolls, greater gliders and pink cockatoos.

The largest case of beef-related deforestation exceeded 1700 hectares – or around six times the size of the Sydney CBD – at Wombinoo Station, whose owner, Warren Jonsson, was instructed to replant a section of land in 2017 after unauthorised clearing.

Back then, he told media that permitting regulations were complicated and expensive, and that if producers did not clear land there would be no food to eat.

“My cattle don’t like to eat ironbark. People don’t like to eat ironbark,” he said.

Jonsson did not respond to a request for comment. Niki Ford, chief executive of Agforce, which represents Queensland beef graziers, said it was not in a position to comment on individual properties without independently verified information about those cases.

“Conclusions of this nature should not be drawn from desktop analysis or unsubstantiated data alone, without appropriate verification and consideration of the circumstances on the ground,” she said.

The report also said that the nation’s biggest beef buyers – Coles, Woolworths and McDonald’s – have not yet met targets they set to eliminate deforestation from their Australian beef supply chains by the end of 2025, due to the difficulty of tracing cattle between properties over the full course of their life.

Woolworths said it had met the target to eliminate land clearing in its direct supply chain and was working with industry to implement full life-cycle traceability.

Coles has also had difficulty tracing cattle over their full life cycle.

“We are committed to engaging directly with our suppliers, and we will continue to work with producers, industry, government and other stakeholders to advance a consistent approach to traceability and verification and reduce deforestation risk within our in-scope beef supply chain,” a spokesperson said.

McDonald’s, which uses Australian beef in an estimated 70 per cent of its outlets around the world, did not respond to a request for comment. According to McDonald’s it sells 49 million burgers each year in Australia.

Pelle said the industry already had a mechanism that would allow for this, known as the National Livestock Identification System, which is used to guarantee hormone-free claims and ensure biosecurity between farms.

“Clearly it could just as easily be used to verify that cattle have come from farms that are deforestation free,” he said.

Industry Association Cattle Australia opposes using the system to protect against land clearing, and rejected the ACF’s findings.

“These organisations are putting legal, regulated Australian land management next to illegal palm-oil deforestation, and neither the World Resources Institute nor the European Union agree with them,” chief executive Will Evans said.

“The EU rates Australia as a low-risk country, and the WRI doesn’t rank us among the world’s major deforestation contributors at all. What training and support do these volunteers undertake? With no peer review and a two-minute tutorial standing in for training, they’ve repeatedly misidentified seasonal change, bushfire events and even established plantations as ‘deforestation.’”

He said Cattle Australia’s opposition to using the NLIS to ensure beef did not come from cleared land was “not about resisting transparency,” but that the system had been developed as a biosecurity and food-safety system by producers.

“NLIS data is collected for disease response, food safety and market-access assurance,” he said. “Handing retailers or advocacy groups direct access to producer-level data outside the system’s own governance would erode the producer trust the whole system depends on.”

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Nick O'Malley is National Environment and Climate Editor for The Sydney Morning Herald and The Age. He is also a senior writer and a former US correspondent.Connect via email.