Atrazine found in Australia river system
By Peter Gardiner | 5th March 2010 A CHEMICAL linked to sex changes in frogs and chemical castration has been found in samples taken from the Noosa River system. However, fish health expert Dr Matt Landos said the levels of atrazine, which is used as a weed killer, were not of sufficient concentration to be the cause of the two-headed fish and other hatchling mutations at Noosa. Dr Landos is part of the State Government’s Noosa River Fish Health Task Force set up to investigate fish deformities from the Sunland Freshwater Fish Hatchery at Boreen Point. Researchers at the University of California at Berkeley found that male frogs grown in levels of atrazine consistent with common agricultural practices either had decreased male characteristics or signs of feminisation. And about 10% turned into females capable of reproducing only male offspring. “Atrazine and other herbicides are a problem in many other rivers of Queensland where they are used far more intensely for agriculture,” Dr Landos said. “There, it has been found in concentrations a thousand times higher than in the Noosa River by researchers from James Cook University. “At these levels, it acts as a herbicide and kills the seagrass beds which are the cornerstones of a river ecosystem.” However, Dr Landos said that atrazine was one of a growing list of chemicals found from testing in the river and around the hatchery. The effects of such mixtures are not considered when the products are registered by the regulator the Australian Pesticides and Veterinary Medicines Authority, thereby underestimating the risks of harm to aquatic ecosystems. Dr Landos said that the effects of this chemical cocktail were being considered by the taskforce. Other agri-chemicals that have been found, some at higher concentrations than atrazine, have been chemicals linked to hormone disturbances such as endosulfan sulphate, trichlorfon, carbendazim and the wetting agent nonylphenol. “In this chemical mixture the levels of atrazine would be unlikely to be sufficient to be a main player in the problem in Noosa.” However, Dr Landos said the use of chemicals linked to agricultural spray drift was now on the top of the probability list for causing some of the syndromes observed at the Noosa hatchery. …
