The operation, carried out as part of Ospri’s TBfree NZ programme to control and eradicate bovine Tb in possums, was the first on DCC land.
For the eradication of bovine Tb, possum numbers had to be kept low - about one to two animals every 10ha, Ospri said.
Scientific surveys could then confirm that disease was no longer present.
Monitoring of the possum population in the Silverpeaks catchment after the 2017 1080 drop pointed to the operation’s success, an Ospri spokesman said yesterday.
The operation had targeted possums but was also intended to reduce the number of rats and other predators.
Following the drop, the possum population was monitored through the use of small wax tags or "bite" tags - tree-mounted orange plastic bases with a wax bait which was chewed on by possums and other species.
The tags were placed at random points along a 200m line and the results recorded after a week.
The number chewed could be analysed to calculate a bite-mark index that correlated highly to possum density.
The low number of tags with bite marks showed the low possum density needed for the Tb eradication effort had been achieved, the spokesman said. Ospri continued to monitor cattle and deer herds in the region.
