The move by the Environment Department, signed by minister Josh Frydenberg on May 10, also modified a ninth condition that required the Indian-owned miner spend $450,000 annually to implement a marine offsets strategy. Those funds will now go to the Reef Trust, possibly from a later date.

"The beaches at Abbot Point are important nesting sites for flatback turtles and the region is a high priority foraging habitat for green turtles," said Imogen Zethoven, a campaign director for the Australian Marine Conservation Society. "Both of these species are listed as vulnerable under federal and Queensland law."

Abbot Point's environment record was already under a cloud after coal sediment entered a nearby wetland and the company may have breached its temporarily elevated pollution limits during Cyclone Debbie in March.

The Terminal 0 expansion at Abbot Point is vital to service the $16 billion-plus Carmichael coal mine Adani hopes to build - with eager federal and state Labor backing- in the Galilee Basin.

At its approval in 2013 by the Abbott government, then environment minister Greg Hunt declared the 95 conditions to be "some of the strictest" in Australian history. These included controls on feral pigs and dogs as part of a turtle plan and the offsets strategy to be reviewed every three years - both conditions now cut.

A spokesman for Mr Frydenberg said that description "is still accurate", with offset liability unchanged and projects that will focus on the same protection issues.

"This change is consistent with the government's 2013 election commitment to establish the Reef Trust and enable it to deliver offsets on behalf of [the Environment Protection and Biodiversity Conservation] Act proponents." he said.

Opponents of the port expansion and mine say the changed conditions add to a lengthening list of concessions by the governments of Malcolm Turnbull and Annastacia Palaszczuk.

These include unlimited groundwater rights, a possible federal loan of some $1 billion to link the mine and port, and a potential $320 million royalties holiday expected to be discussed at a state cabinet meeting on Monday.

'Their request'

An Adani spokesman said the EPBC amendments had been at the government's "request and direction" to align conditions with the Reef Trust.

"The new condition is not an easing of requirements," he said. "The same payment amount is required, for the same period and for the same purpose.

But Larissa Waters, the deputy Australian Greens leader, said "the gifts for this billionaire company from Labor and the Liberals keep stacking up".

"Will any future breach of conditions be simply excused and waved through?", Senator Waters said. "Cutting out huge chunks out of Adani's conditions makes a mockery of Liberal and Labor claims that this project is governed by 'strict' conditions."

Tony Burke, Labor's federal environment minister, said minister Frydenberg "really needs to explain this one".

"If there has been any weakening of conditions [under the EPBC Act], I don't see how that could be justified," Mr Burke said. "How is it possible for conditions affecting turtles and the Great Barrier Reef to be weakened during a time when the health of the reef has only declined?"

Offsets offside

The Queensland government is expected to finalise soon its own report into Abbot Point's handling of pollution during the cyclone, a category-4 storm the company has described as a one-in-500-year event.

Ms Zethoven said the whole concept of offsets was itself against the World Heritage convention that Australia had signed up for.

The convention states government are supposed to protect or improve sites, she said. It doesn't say "you can damage here provided you substitute over there".