HARBOUR dredging could be responsible for a spike in fish deaths at Gladstone, and water testing should be expanded.
And water testing should be expanded to include metals and organic chemicals in sediments on the harbour floor, a report has found.
The desktop review headed by Australian Institute of Marine Science chief executive Ian Poiner found the cause of the fish disease remained unknown but it questioned whether the current water testing regime at the heavily industrial port, north of Brisbane, was "fit for purpose".
Gladstone fishermen blame Australia's largest dredging project to enable development of the multi-billion-dollar LNG export industry at Gladstone for the poor harbour health.
The report said there were a number of possible explanations including netting, chemical damage, nutritional issues or parasites and bacteria but did rule out dredging as a possible cause.
The panel said fish were normally good indicators of eco-system and environmental health. It concluded there was "an issue of concern around the health of some species of fish in Gladstone Harbour and this is possibly caused by environmental factors, but the extent of the issue is currently not known."
Queensland Fisheries Minister Craig Wallace welcomed the report as vindication that seafood from Gladstone Harbour was safe to eat.
The release of the report in Gladstone came as a local fisherman produced a shovel-nosed shark covered in red sores that he said had been caught in the harbour yesterday morning.
"They say they don't know what's wrong with the fish. We know what's wrong -- it's the dredging," fisherman Trevor Falzon said. "The fish population in Gladstone is declining big time."
Gladstone Fish Market owner Simon Whittingham said the report had raised a lot of the concerns put forward by the fishing industry.
"I think the report has got a lot in it that the government needs to listen to. I am not a greenie or a tree-hugger but what is happening here is just cruel," he said.
Gladstone Ports Corporation chief executive Leo Zussino welcomed the report and said he would make a "considered response" on Monday.
"The corporation notes the comments by Dr Poiner that the independent panel could not find fault with the water quality monitoring programs."
However, the report said: "The panel discussed the focus on total (particulate plus dissolved) metals data in water and a lack of monitoring data for metals in sediments and the apparent lack of monitoring data for organic chemicals in sediments and water.
"Given the focus of the monitoring programs, the panel discussed whether the available water quality data is fit for purpose.
"The panel noted the current parameters measured may not provide an appropriate trigger for ecosystem health problems that may be responsible for the observed fish health issues in Gladstone Harbour.
"For example, mercury, which can be highly toxic due to formation of methyl mercury, was not included in the list of tested metals."
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