New restrictions on the use of a weed killer harmful to the Great Barrier Reef won’t protect the World Heritage listed asset, a conservation group says.
The World Wildlife Fund (WWF) has attacked new rules set by Australia’s chemical regulator, which has banned the use of diuron on certain crops during the upcoming wet season.
The Australian Pesticides and Veterinary Medicines Authority (APVMA) says the ban is aimed at protecting aquatic ecosystems from runoff of the chemical, commonly used by cane, tea, banana and pineapple farmers.
But WWF’s pesticides policy manager Martin Breen said the regulator had caved in to the demands of chemical manufacturers, and the wet season ban was meaningless.
Diuron has been linked to coral bleaching and loss of seagrasses and has been found 60km inside the Great Barrier Reef Marine Park.
In September, scientists from Queensland’s Environment Department found traces of dangerous pesticides at up to 50 times the levels deemed safe in waterways flowing onto the reef.
Three chemicals, including diuron, were at toxic levels exceeding national standards for contamination of freshwater ecosystems at eight sites along the Great Barrier Reef coast.
Mr Breen said the only way to protect the reef was to completely ban the use of diuron, which remained effective months after it was sprayed on crops.
“You could actually apply this stuff in April or May and it could still be in the soil in high concentration in December,” he told AAP.
“Then if you get a rain event at any time of the year it just gets washed straight off into the reef. The only safe level of use for this chemical is no use at all.”
Mr Breen said diuron manufacturer DuPont proposed the wet season ban, but a federal Department of Sustainability, Environment, Water, Population and Communities (SEWPaC) report found the argument behind the ban was “hard to sustain”.
It said Queensland’s wet season was so variable that it would be impossible to choose a low risk time to spray.
DuPont and a canegrower’s organisation also proposed to cut their use of diuron by half to 1.8kg per hectare, which is the level that has now been approved by APVMA for application outside the wet season.
However, this level is still 11 times higher than that deemed safe in the SEWPaC report.
“It seems like APVMA may have taken only the advice of the chemical companies and ignored the advice of the environment department,” Mr Breen said.
“They need to explain what the logic is in that and ask how that protects the environment.”
An APVMA spokeswoman said it recommended a diuron rate of 1.8kg per hectare based on existing Queensland regulations for sugar cane and had not buckled to commercial pressure.
“It is entirely feasible that other organisations have taken account of this regulatory rate in formulating their submissions to the APVMA,” the spokeswoman said in a statement.
She said the rate was still under review while APVMA considered new data, and the wet season suspension of diuron was an interim step based on the prediction of a wet summer in 2011-2012.
