A 1080 drop in the Pelorus Sound will be included in a nationwide pest control programme sparked by a plague of rats and stoats throughout the country.
Department of Conservation Marlborough services manager Roy Grose said consent by Marlborough District Council for the drop had already been granted and they expected it to go ahead in August.
The aerial drop would cover just over 4000 hectares of forest around the Mt Stanley and outer Pelorus Sound area, as part of national operation Battle for our Birds, Grose said.
The operation was sparked by an unusual "beech mast", which had caused a spike in numbers of rats and stoats nationwide.
About 200kg of beech seeds had fallen per hectare in the Mt Stanley area, and tracking tunnels used by DOC to measure the density of rats showed an "extremely high" population, Grose said.
A higher density of beech seeds meant a larger food source for rats, which in turn meant an increase in stoats, he said.
When the seeds ran out, the rats and stoats would target native species, including fantail, grey warbler, bellbird, tui, and snails.
"If we don't do something this year, a lot of native species will go down the gurgler [in terms of numbers]."
It had been about 10 years since the last beech mast, which had come following a "prolific flowering season" last spring, he said.
DOC was in the planning stages of the drop and were yet to apply to the medical officer of health, Grose said. They were also working with anti-1080 groups.
Conservation Minister Nick Smith confirmed operations would be carried out in 29 forests throughout the country, covering 700,000ha by November. Another 14 forests covering 200,000ha were on "close watch".
The operation would not involve record amounts of 1080, Smith said.
The cost of the programme would be between $9 million and $12m.
- The Marlborough Express
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