A new 1080 poisoning technique, including doubling the drop, will be trialled near Haast this winter.
Zero Invasive Predators (Zip) was in Hokitika on Friday to release details to the West Coast Conservation Board meeting.
This winter in the Jackson-Arawhata area it will try to get rid of all possums and rats. It said a trial last year near Taranaki was encouraging.
Zip chief executive Albert Bramley said that unlike regular 1080 drops, the proposal was to do the non-toxic pre-feed twice rather than just once.
It would then sow the poison baits at double the regular rate, at 4kg per hectare rather than 2kg.
''If the technique works, we hope to completely remove these animals and get out of using 1080 long-term,'' Mr Bramley said.
They wanted to stop the long-term, repeated use of toxins which were not good for wildlife. That would also help buy goodwill from communities, he said.
The West Coast had been chosen for a trial because it was ''defendable'', with mountains on one side, and rivers that pests did not like crossing.
The proposal was to have lots of traps on the sides of the rivers where pests had been to stop them re-invading. If they did cross those rivers, traps would be in place.
''If it does work, this is the place to roll the solution out,'' Mr Bramley said.
However, if there were survivors, the second phase of the poisoning operation would be triggered, consisting of two further pre-feed applications followed by a second application of 1080.
The two phases would use different ''flavoured'' lures to reduce the chance target species were put off by a particular flavour. Both 1080 operations use the same strength toxin, although the cereal pellet type would change.
The earlier trial appeared to have successfully removed all possums and left fewer than 20 ship rats in an intensively monitored 400ha block, he said.
Zero Invasive Predators Ltd was established by the Department of Conservation and the NEXT Foundation in February 2015 to develop the capability to completely remove rats, possums and stoats from large mainland areas, then defend those areas from re-invasion.
Hari Hari anti-1080 protester Danny Lane tried to hear the talk at the conservation board meeting, but he was not allowed in. He was later allowed to address the public forum.
''There's been no public consultation,'' Mr Lane said.
''No-one knows about it.''
-By Laura Mills of the Greymouth Star
