Controversial dredging of Victoria’s Port Phillip Bay to enable bigger ships to use the port facilities ended recently, but the conflict between environmental groups and the Port of Melbourne Corporation is far from over, writes Christie Sinclair.

Dredging ships have sucked 22 million cubic meters of sand and clay from shipping channels in the Bay. Image: Wikicommons

Since 2003, the organisation Blue Wedges has fought against the $969 million project to widen shipping channels in Port Phillip Bay. The community coalition attempted to overturn the project in January 2008 but not only did the case result in the Federal Court ruling in favour of PoMC, the state government authority in charge of the dredging held the threat of obtaining costs over Blue Wedges protesters as a tool to silence them.

Blue Wedges secretary Trevor Buck said that the Corporation was effectively trying to warn Blue Wedges or anyone else off, making it clear to all community groups the danger in disputing government decisions in court.

“Port of Melbourne have been given the right to pursue costs against us, so far they haven’t, but what that means is we couldn’t go back to court because we had a cost order hanging over our heads,” said Mr Buck.

Mr Buck believes that the effectiveness of the group was destroyed by the tactics of the Corporation. He said that further legal action against the dredging would have occurred but for the threat of costs.

Until February 2008, the shipping channel through Port Phillip Bay was not deep enough to facilitate large container ships. Ships carrying 4200 containers were unable to enter the Port of Melbourne even at high tide. The solution, as proposed by the PoMC, a statutory corporation owned and run by the Victorian Government, was to deepen the channels in Port Phillip Bay in order to accommodate the larger container ships. The proposal involved dredging an estimated 22.9 million cubic metres of material from five sites in the bay to increase the existing channels to a depth which would allow ships carrying 8000 containers to enter and exit the port.

Dredging the bay was championed by PoMC as bringing about enormous economic benefits, but many in the community were concerned that these benefits would be delivered with inevitable and unacceptable environmental costs.

Blue Wedges, the main group involved in lobbying against the project, is a coalition of bay user groups, comprised of people who enjoy using the bay and who are concerned about environmental impacts. They are not, Trevor Buck said, ‘radical greenies.’ According to him, they are just a group of people concerned about the long term health of the bay.

The main argument put forward by environmentalists was that despite the assurances from the state government and its agencies of it having no significant impacts, the exact consequences of the dredging wouldn’t be known for a number of years.

Chrys Smyth, ACF’s Marine Campaign Coordinator, said a lack so far of documented negative environmental effects can be attributed to poor monitoring of environmental impacts by the Port of Melbourne Corporation and others.

“The monitoring that has been conducted was not adequate and it was often done in the wrong places at the wrong times.”

Mr Buck believes that it could take years for the long term damage to be revealed.

“It will probably be about five years before we start seeing any real problems. For example, it’s likely to be at least that long before the lack of snapper recruitment will transpire into people not catching snapper anymore.”

While media releases from the PoMC claim that the health of the bay remains unchanged, both Mr. Buck and Mr. Smyth believe there is evidence of impacts on the fragile marine ecosystem already.

Snapper in the bay is a vital resource to the Victorian community. While there has been a rise in the number of snapper in the bay since the elimination of scallop dredges in 1995, snapper recruitment in 2005 and 2006, during the trial dredge, was referred to as a ‘failed spawn.’

“Interestingly Snapper recruitment doesn’t seem to have been recorded by the PoMC since the trial dredge,” said Mr. Buck.

He also noted that a recent survey of anchovy showed that an entire breeding season had been missed, extra ordinary tidal effects and flooding in low lying areas following storms had occurred and abnormal fish kills had become noticeable in the bay. Although testing had been carried out and it was clear that such effects became noticeable after dredging began, Mr. Buck said that scientists believed that these changes were not a result of the channel deepening, but they could not determine why these abnormalities were suddenly occurring in the bay.

“There are effects that they are just going to dismiss as something like global warming,” he said.

“It is difficult to judge exactly what has occurred, but our information shows there has been a noticeable effect on seagrass meadows, anchovies, and a decline in the amount of fish in the bay,” Mr Smyth said.

Much of the ACF’s research has been conducted in conjunction with scientists from the Australian Marine Ecology and Monash University who are monitoring Port Phillip Bay as part of the ACF’s independent Bay Monitor program.

Their research has revealed that dredge plumes have spread further southward and beyond the predicted limits of the Supplementary Environmental Effects Statement. Further studies on seagrass meadows in Port Phillip Bay have showed that these dredge plumes and turbidity from dredging, resulting in changed light climates, have drastically reduced seagrass habitats, which are very sensitive to changes in lighting.

There is now evidence to suggest that dredging the entrance of the Bay has resulted in the widespread damage of sponge gardens.

Despite claims that monitoring has not been comprehensive enough to pick up the changes, the PoMC publicly maintains that the channel deepening project adheres to a rigorous set of environmental controls, the most ‘comprehensive ever applied to a dredging project anywhere in the world.’

Official surveying and monitoring of dredging impact is conducted by the PoMC and various government bodies employed by the corporation. A spokesperson for the PoMC said, “External monitoring is conducted by a number of agencies depending on the program. For example, the Department of Sustainability and Environment and the Environmental Protection Authority both conduct monitoring. All monitoring conducted is also subjected to internal and external audits.”

“As forecast in the project’s environmental assessment, to date there have been no indications of significant environmental disturbances from the dredging, notably in relation to water quality, tides, tidal currents, sea level and marine life,” said the spokesperson.

But the Supplementary Environmental Effects Statement conducted in 2007 predicted that there would actually be a number of lasting impacts from dredging on the bay. This included a rise in sea level of about one centimeter as a result of the deepening of the shipping channels and the two dredge material spoil grounds in the bay.

Since the institutions employed by the PoMC are linked with the Victorian Government, as is the PoMC, opponents of dredging question their impartiality and whether they have the ability to keep information from the public.

“It’s the concept of manipulation of data that is a concern to people,” said Mr Buck. “Any evidence of impact on the bay can be hidden away, there are many other stories that they can put over it, and it makes it really hard to nail it down.”

In late November, PoMC announced that it had completed the project ahead of schedule and at least $200 million under budget. However, the next phase of the Channel Deepening Project, called maintenance dredging, is about to commence on the Yarra and Maribyrnong rivers and is expected to last for another two years.

Christie Sinclair is a Journalism student from Monash University.