Toxic Truth: Fish contamination study call

A NEW study into toxic fish in Lake Macquarie should be done if the community demands it, University of Canberra Ecochemistry Professor Bill Maher says.

Professor Maher worked on a 2006 study, which found heavy metal contamination in Lake Macquarie fish was at levels that cause fish deformities and impair their reproduction.

Lake Macquarie fish had elevated levels of selenium, lead, cadmium and zinc in muscle and gonad tissues, the study found.

Professor Maher said heavy metal levels in the lake had decreased with the closure of Pasminco in 2003, improved handling of ash at power stations and other stormwater improvements.

But he said another study should be done if the community was concerned about metal levels in fish.

Hunter New England Health has said it is OK to eat the lake’s contaminated fish, as long as they are not consumed in large quantities.

But the health authority has consistently urged people to be cautious about eating fish caught around power stations and Cockle Creek, where contaminants are most prevalent.

People still fish in these spots though, with many unconcerned about the risks.

The Newcastle Herald found no signs along Cockle Creek warning against fishing, while fishing is allowed around power station canals.

Hunter New England Health’s website says an average adult can safely eat about 1.35kilograms of fish or about six average fish fillets from the lake a week.

The main concern had been selenium levels, but the health authority  said they were ‘‘not high enough to cause any illness in people in the short term’’.

‘‘It is highly unlikely that a person could eat enough fish in the long term to have any ill effects,’’ it said.

However, NSW Health does not recommend eating shellfish from the lake.

A 2001 NSW Health report on metal contamination of NSW fish said ‘‘routine surveillance and periodic surveys of specific locations’’ should occur in Lake Macquarie.

A University of Sydney report from 2006 predicted that lead, cadmium, zinc and copper could increase by up to 75per cent in the lake’s southern reaches by 2020.

“We were saying that cadmium was decreasing in the north because supply was reduced or minimised. In time it will keep travelling out into the lake,” geoscientist Professor Gavin Birch, who conducted the sampling, said.

However, Professor Maher said heavy metals were probably not shifting from north to south because ‘‘the big spit’’ which is Wangi Wangi, divided the lake.

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