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Melbourne’s Child

We are a group of Melbourne doctors who have taken a keen interest in the proposed deepening of Port Phillip Bay and the Yarra River. We are concerned because of the harm this project could cause to the health and well being of families.

We know that parents of young children want the very best for their children, especially concerning their health and well being. This knowledge, and the fact that children would be most at risk, has spurred us to raise some very important potential health risks associated with the present channel deepening proposal. We are also concerned for the health of future generations - decisions made now will leave a very long lasting legacy of potential disease.

There are two main areas of concern should the channel deepening project go ahead.

Firstly, there is a significant risk of toxic algal blooms in the Bay. Should toxic algal blooms occur, there would be offensive odours around the Bay, and the water would be unsafe for swimming. A pleasant outing to the beach would no longer be possible. Shellfish caught in the Bay would not be safe to eat, as they could be contaminated by dangerous toxins such as Alexandrium catenella, an organism which contaminates oysters, mussels and scallops. When humans consume shellfish contaminated with Alexandrium catenella the result can be paralytic shellfish poisoning see:   http://www.aims.gov.au/arnat/arnat-0008.htm which can be fatal.  Lesser infections cause severe bouts of vomiting and diarrhoea. If large areas of the Bay turned to this state, it would be almost impossible for it to fully recover, and we would be left with a much degraded Bay – no longer the wonderful playground it now is.

Secondly, are the risks associated with disturbance of toxicants in the Northern end of the Bay. Upward of 3 million tonnes of contaminated sediment from the Yarra River bed would be dredged and dumped in Port Phillip Bay. These contaminants are a legacy of early industry and farming practices which leached into the Yarra, settled over the years deep into the clayey River bed and are now trapped there – in a relatively harmless inert state.  However, because even larger vessels with deeper draught (more underwater keel depth) are intended for the Port of Melbourne, 2 ½ to 3 metres of extra depth would be required in the Yarra River – as far up as the Bolte Bridge. The contaminated material is known to contain Lead, Mercury, Arsenic, Tributyl Tin, DDT, Cadmium, Petroleum and Chlorinated Hydrocarbons. Once removed from the Yarra Bed the material is earmarked for a proposed dump site off Brighton Beach, but its removal and dumping would pose a risk to human health as the sediments are stirred up and enter the water column. Heavy metals especially are cumulative poisons, and they go up through the food chain to fish and then to humans. Melbournians eat many thousands of tonnes of fish caught in Port Phillip Bay every year.  

Health risks associated with these chemicals and metals include higher risk of birth defects in babies when ingested by pregnant women. Mercury is a well known cause of impaired neuro-development of children. Other heavy metals can also cause complications including intellectual disability, kidney problems, vascular disease, and impaired immunity. 

The Port of Melbourne Corporation (proponent) acknowledges these risks but has not yet produced a plan to prevent these dangers from becoming a reality. The Independent Panel members who deliberated for many weeks over the Environmental Effects Study (EES) evidence could not be satisfied that it was possible to safely move this contaminated material and prevent these toxicants from entering the food chain of Port Phillip Bay.

The channel deepening project is many times larger than any previous project undertaken in the Bay. The Independent Panel referred to is as a MEGA project on a global scale. The Port of Melbourne Corporation could not provide information on any similar sized project anywhere in the world.   By their own admission, the proponents really cannot predict what the full effect on the Bay environment will be.

We urge that the government take these public health risks very seriously before making any decision regarding channel deepening for Port Phillip Bay.