Two further rounds of independent water quality sampling in Port Curtis show no evidence that water quality is affecting fish health or that dredging in Gladstone Harbour is causing environmental harm.
This week, Department of Environment and Resource Management Director-General Jim Reeves released a peer-reviewed report of tests taken in late October and data from further independent testing conducted late November.
'The sampling shows no clear pattern in the water quality results taken across the Port Curtis region to suggest that dredging was having any obvious impact on water quality,' Mr Reeves said.
'What we are seeing is a natural month to month variation across all testing zones. There was no evidence that turbidity, pH, oxygen levels, salinity or temperature had any negative impact on water quality in Port Curtis harbour or its estuaries, or fish health concerns.
'Neither was there any clear pattern in the number of exceedances of dissolved metals guidelines for aluminium and copper.
'Turbidity levels in November were generally higher than in October but lower than in September.
'There were high levels of turbidity and nutrient levels, especially nitrogen, found at Boat Creek. This is a considerable distance from the dredging, and the localised nature suggests high turbidity can occur naturally in some areas within Port Curtis.
'With the exception of aluminium, generally the concentrations of metals and metalloids were lower in October and November compared with the first round of sampling in September.
'Dissolved aluminium was found at 18 sites surveyed throughout Port Curtis area, compared with one site in October and six sites in September, indicating the dynamic and highly variable nature of Port Curtis.
'The November data found no dissolved chromium at any sites, and levels of total zinc were within guidelines at all sites other than at Boat Creek which may be related to the elevated turbidity at that site.
'From the data available, there is no clear connection between fish health and the results of the monitoring that has been undertaken to date. Monthly sampling will continue and the results will be made public.'
The independent Gladstone Fish Health Scientific Advisory Panel’s report also confirmed that there is no risk to human health.
Fisheries Minister Craig Wallace said the report concludes that water quality monitoring results do not indicate unusual trends which establish a causal relationship between the condition of fish and water quality or sediment in Gladstone Harbour.
After an extensive review of available data and literature, the Panel has not been able to provide a conclusive view on the cause of the fish conditions observed in Gladstone Harbour and has recommended further monitoring and research continue to be undertaken.
The new program will involve regular public reporting and the Government will consult the Chair of the Scientific Advisory Panel, Professor Ian Poiner on its development.
Mr Wallace welcomed the report’s conclusions for the Gladstone fishing industry.
'The Panel was established to provide an independent scientific assessment of fish health in Gladstone, and we now know conclusively that there is no risk to human health from handling fish with the identified parasites, lesions or redness,' Mr Wallace said.
'Fisheries Queensland has found approximately 95 per cent of non-barramundi fish caught in their monitoring in the Gladstone area are in good health and now that the Panel has released its findings, there should now be no doubt in anyone’s mind that local seafood for sale is a good, safe product.
'Under the Food Act, any animal product which is not fit for human consumption cannot be sold, and it has been emphasised by the Panel that fish showing signs of disease should not be consumed.
'The report acknowledges barramundi appear to be more strongly affected than other fish species, likely due to population stress following the flooding events of last summer which caused 30,000 large barramundi to spill over the Awoonga Dam into Gladstone Harbour.
'The incidence of ill health in mud crabs and prawns was noted by the Panel to not be unusual compared to previous studies in Gladstone Harbour and elsewhere.
'Considerable damage has been done to the reputation of Gladstone seafood and I urge the local community and all Queenslanders to rally behind the industry to rebuild the brand.
'Panel members were not paid for their work on this report and I would like to thank them for donating their valuable time to provide expert analysis and advice.'
The latest test results are available at www.derm.qld.gov.au/gladstone