An operation to reduce high possum numbers, possibly infected with bovine tuberculosis (Tb), in rural areas around Mosgiel has so far eliminated about 130 of the pests.
Surveys had shown possum numbers in 1800ha of Wingatui, Abbots Hills, Halfway Bush and Silver Stream areas near Mosgiel had increased to a level where they posed a risk of spreading Tb to nearby cattle and deer herds.
''Possum numbers have been found, as expected, to be higher in patches,'' TBfree New Zealand Southern South Island programme manager Brent Rohloff said.
The operational area included lifestyle properties, commercial forestry and the Invermay AgResearch facility.
The area was a Tb-free ''buffer'' between land free of Tb and areas where the disease was known to still persist in wildlife.
''It is important that control work is regularly undertaken in 'buffers' to ensure that possum numbers are kept low and even, to minimise the risk of Tb spreading from infected wildlife to farmed cattle and deer.''
The ground-based control work was expected to be complete in December. Contractors were consulting landowners about the most appropriate control method for their property.
Larger areas of farmland and some of the smaller lifestyle blocks had already been completed, he said.
The contractor was using a combination of Timms traps and cyanide-based Feratox products to kill the possums.
Ground control work last took place in the area about four years ago and was extremely successful in lowering possum densities, he said.
Scientific evidence indicated possums were responsible for about 70% of new herd infections in Tb risk areas.
Warning signs had been put up in the operational area.
