The reef dumping put coral and fish health at risk, Australian Greens environment spokeswoman Larissa Waters said.

“Since 2000, 22 million cubic metres of dredge spoil has been approved to be dumped in our precious reef – that's more than 13 MCGs worth,” she said.

“Because of wind, wave and ocean current action, the dredge spoil travels and can end up smothering precious coral ecosystems and affecting fishing areas – all just to save the big mining companies the cost of disposing the spoil on land.”

Waters said the Great Barrier Reef Marine Park Authority informed her that since their scientists recently started using 3D modelling and factoring in deep ocean currents, they had found dredge spoil sediment was moving much further than previously claimed by dredging companies.

“It's environmental negligence to let the big mining companies dump their dredged port waste in the Great Barrier Reef, especially when we still don't know the full impact and when the UN is warning the reef could be added to the list of World Heritage sites in danger in a year,” she said.

Leader Christine Milne said the Greens wanted to put a stop to the dumping of dredge spoil in the Great Barrier Reef World Heritage Area and polling shows more than 90% of Australians agree.

“We're taking to the election a policy of no new permits for offshore dumping in the reef and no new permits for dredging in the reef unless there is a plan to dispose of the dredge spoil onshore,” she said.