Meanwhile, Auckland Council yesterday voted to switch to 1080 for pest control in the Hunua Ranges Regional Park, which supplies 65 per cent of the city's freshwater supplies. At present, pests are managed using cyanide and other poisons.
From next winter, when pests are searching for food, the council will use helicopters to dump 1080 pellets in the park. It says stringent controls will ensure the poison does not enter water supplies, which it promises to carefully monitor.
The move will save almost $1 million and ensure pesticide is spread over the 17,000ha ranges.
The pesticide has been given the all-clear by the Parliamentary Commissioner for the Environment, Dr Jan Wright.
But 1080 remains controversial and is regarded with suspicion by opponents who argue that sub-lethal amounts can disrupt the body's immune system and lead to long-term health problems.
The poison is banned in most countries. New Zealand is the world's largest 1080 user.