2000 October: Gippsland Lakes Mosquito Spray Plan: Pesticide of Concern: Temephos

Pesticide Spray Plan Draws Fire

The Age Wednesday October 18, 2000


East Gippsland Shire is planning aerial spraying of the Gippsland Lakes with a pesticide linked to wildlife deformities.

The council claims that spraying to control mosquitoes is necessary to reduce the risk of diseases such as Ross River virus and Barmah forest encephalitis and to protect tourism.

But the plan has alarmed residents, who say aerial spraying will endanger human health as well as frogs, fish and birds.

The lakes are listed under the Ramsar international treaty to protect migratory birds. The ecosystem is already severely degraded by farm pollutants and low river inflows due to high diversions for irrigation and the Thomson dam.

The council wants to spray an organophosphate pesticide called Abate. Chief executive Graeme Pearce said Abate had been hand-sprayed for many years, but aerial spraying was being considered to apply it “more effectively”.

The safety sheet for Abate warns that it should not be used where birds are foraging, particularly where there are large quantities of larvae or shallow depths where birds can feed easily. It says treated water may also affect molluscs and crustaceans.

Organophosphates damage nervous systems. The US Department of the Interior has linked Abate to deformities and reduced breeding in frogs, and lowered hatchings among birds. It is highly toxic to bees and low to moderately persistent in the environment.

Mr Pearce said the council generally accepted that spraying reduced mosquito numbers, although it had not studied whether numbers were linked with the incidence of mosquito-borne disease.

The council has sought Department of Natural Resources and Environment approval to start spraying as soon as possible. Mr Pearce said drift would be minimal due to low flying and targeting techniques.

The department’s Gippsland manager, Tony Edgar, said all agencies involved, including Land Victoria and Parks Victoria, were still discussing the council’s application.

Department of Human Services spokesman Bram Alexander said spraying did not eliminate mosquitoes or the risk of disease. “Nine times out of 10, the mosquitoes are a nuisance rather than a real risk.”

Jim Reside, from Friends of the Gippsland Lakes Wetlands, said mosquitoes were a problem every summer, regardless of treatment. “Spraying them is very short-term, then they are back again,” he said.

Tambo Environment Awareness Group spokeswoman Loris Duclos said the larvae were a major food source for fish and birds. “It is just ridiculous to attempt to wipe out the bottom of the food chain in an area dependent on fishing.”

She said aerial spraying would contaminate rainwater run-off for household tanks.