Australia's federal government formally approved a plan on Tuesday to dredge vast swathes of seabed sediment from an area near the Great Barrier Reef as part of a major coal port expansion, after rejecting arguments by environmentalists that it will hurt the area's fragile ecosystem.

Environment Minister Greg Hunt initially approved the expansion of the Abbot Point coal port in northern Queensland in 2013, but the process has been repeatedly delayed and the plan repeatedly revised amid protests by conservation groups.

The expansion requires a massive dredging operation to make way for ships entering and exiting the port, which is located 20 kilometers (12 miles) from the nearest coral reef. The original plan called for more than 3 million cubic meters (106 million cubic feet) of dredged mud to be dumped on the reef.

Under the new plan, the dredged material will be disposed of on land in an industrial area, a spokeswoman for Hunt said in a statement. The plan still requires the approval of the Queensland government.

The expansion calls for up to 1.1 million cubic meters (39 million cubic feet) of dredged material to be removed from the area.

Conservationists have argued that the dredging would be catastrophic to the delicate reef. Beyond the initial concerns that the dumped sediment would smother coral and sea grass, environmental groups have said the increased shipping traffic would boost the risk of accidents, such as oil spills and collisions with coral beds.

International conservation group WWF condemned Tuesday's decision, saying the dredging will still threaten sea life and noting that the dumped sediment will now be disposed of in an area adjacent to wetlands that are home to thousands of birds.