The Turnbull government has quietly axed eight environmental conditions aimed at protecting vulnerable turtle species set to be affected by Adani's proposed $3 billion coal terminal expansion at Abbot Point in Queensland.

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.