Millions of larvae of a two-headed fish sighted in a creek in Noosa, Queensland, have raised serious environmental concerns. An expert panel did blame it on agricultural chemicals, but felt the contamination was too small to have any adverse impact.
The report released by the Noosa Fish Health Taskforce states very low levels of chemicals were found at the site about 2km down stream from the Sunland fishery and a macadamia farm at the centre of the investigation.
The owner of the fishery raised concerns about the use of agricultural chemicals after two-headed fish larvae were discovered on her property. A leading expert then called for the chemicals to be banned.
Three areas were under investigation and positive results were returned by two samplers who examined water where Cooloothin Creek enters Lake Cootharaba, Sunshine Coast Daily reported.
Chemicals found include Carbendazim at 0.4 of a nanogram per litre, Atrazine at 9.65 nanograms per litre, and Metolachlor at 14.75 nanograms per litre. A nanogram is one billionth of a gram.
Primary industries and fisheries minister Tim Mulherin said he had been advised the levels detected were so low they would pose no danger to human health and were well within guidelines.
"Samplers upstream and samplers closer to these two properties returned no detected levels of agricultural chemicals," Mr Mulherin said.
"The result gives the government's taskforce additional data to examine as it investigates any links between fish health problems at the hatchery with the broader ecosystem.
"These new results will be added to the data already available and will be subject to rigorous scrutiny and analysis by the taskforce scientific sub-committee and will be included in the taskforce's interim report due to me next week."
Sunshine Coast central are population health unit public health physician Dr Andrew Langley said such small amounts meant the findings were negligible.
"The results do not indicate that there is a risk to human health from drinking the water or recreational use of the water," Dr Langley said.
Sampling was undertaken by the department of environment and resource management during January and February.
Aside from agricultural chemicals, water contaminants commonly associated with human settlement were also detected.
The source of agricultural chemicals is yet to be determined.
National Toxics Network spokeswoman Jo Immig, who has called for bans on carbendazim and endosulfan, said the findings confirmed her fears.
"We're pleased they are at low levels but that doesn't excuse their presence there at all," Ms Immig said. "This is just one detection. How often does this go on?
"There are serious concerns about carbendazim and it is linked to birth defects. It shouldn't be used.
"Atrazine also has been under the spotlight because it is an endocrine disruptor (a chemical that interferes with hormones) at very minute levels and is recognised in Europe as such.
"Atrazine has been linked as a breast and prostate cancer promoter.
"Any level of metolachlor in rivers is concerning because of evidence that it persists in the environment and bioaccumulates in edible species of fish. Its adverse effect on growth and development raises concerns on its effects on human health."