Conservationists have been slapping each other on the back this week after plans to dump five million metric tons of mud into the Great Barrier Reef Marine Park has been cancelled. However, people are now asking where the mud will go, and aren't getting much of an answer.

The mud is expected to be drudged up from the ocean floor as part of a port expansion in northeast Australia. Last month, Environment Minister Andrew Powell found himself at odds with reef conservationists and activists after minister Greg Hunt and the Great Barrier Reef Marine Park Authority actually approved the dump of dredged sediment onto the reefs.

In fact, according to a Courier Mail report, Powell has been working to stop UNESCO from listing the Great Barrier Reef as a region in danger. He repeatedly cited a 2009 Australian Institute of Marine Science report, which claims that extreme weather, coral bleaching and crown-of-thorns starfish - not human activity - are the largest threats to reefs.

However, an independent study recently published in the journal PLOS One refutes those claims, finding that corals near dredging sites face a significantly increased chance of disease. According to the study, excess sediment from dredging dumps can cloud the water, blocking sunlight and hampering corals' natural ability to sieve the ocean for food. (Scroll to read on...)

Supported by scientific evidence, public outcry against the mud dump quickly mounted, and the consortium behind the port expansion plans has reportedly abandoned their dumping decision.

A spokesperson for Minister Hunt told New Scientist that new proposals are being drawn up to dispose of the dredged sediment on land, although it has not been revealed where that may be.

Selina Ward, a reef ecologist from the University of Queensland, added that while she's happy about this turn of events, "the vital question [now] is where they dump it."

Ward had co-authored a petition signed by more than 230 scientists that had begged the Port Authority to reject the expansion plan - designed to help support a growing coal trade in Australia - entirely.

She's now concerned that with the expansion still on its way, the dredged sediment could wind up being dumped on vulnerable local wetlands.