One of the most important decisions in recent eco-political history has been delayed, with the Federal Environment Minister pushing back his call on dredging near the Great Barrier Reef by more than a month.

There have been few planned infrastructure works that have gained as much attention as the Abbot Point coal port expansion in Queensland, if approved the $6.2 billion expansion of the coal port would see four additional coal terminals built to provide an extra annual capacity of 120 million tonnes. The expansion would make Abbot Point one of the largest coal ports in the world, with seven terminals and an annual capacity of almost 300 million tonnes.

Environmental groups have opposed the expansion since its announcement, saying the port is too close to the Great Barrier Reef and the increased traffic from large ocean liners would be disastrous to the fragile nearby ecosystem. The United Nations’ environmental arm has said the Reef is at risk of being placed on the “World Heritage in Danger” list, if the planned expansions are allowed to go ahead.    

Greens Senator Larissa Waters welcomed the move by Environment Minister Mark Butler to delay approval, saying "he can now take the opportunity to get across the information and see that this will be a damaging proposal for the Reef... what's really important is that on August 9 he says 'no' to this expansion.”

A large amount of the concern is to do with the requirement for massive dredging work, as sediment that is disturbed can cloud oceans and travel in plumes over great distances. Ms Waters says "there's a proposal for three million cubic metres of dredging in the Great Barrier Reef world heritage area and then dumping that sea bed right back into marine park waters... the sediment doesn't sit where it's placed, it can move."

Greenpeace has been outspoken on the issue as well, saying it is opposed to any dredging or expansion of the Abbot Point terminal.