The pest control in the Tennyson Inlet area was carried out to protect the area’s high value native forest, at risk giant snails and native birdlife.
The DOC review followed bait accidentally falling into a Nydia Track area that was excluded from the aerial bait distribution under a Medical Officer of Health condition for the operation.
Bait fell near some people on the track. The Nelson Marlborough Medical Officer of Health Dr Ed Kiddle said at the time that any risk to physical health from this was likely to be almost zero.
The review found people should not have been allowed on the track during the bait application given consenting authorities’ expectation the public would not be allowed on the track.
DOC North and Western South Island Conservation Services Director Mike Slater said the department had received a formal warning from the Nelson Marlborough Public Health Service in relation to baits falling into the excluded track area being a breach of its condition.
“Failure to meet the requirements for aerial 1080 operations is unacceptable and we are ensuring we take measures to prevent a recurrence of the incidents that occurred with this Marlborough Sounds’ operation.
“Our internal review confirmed we have thorough systems and standards for safe delivery of aerial 1080 operations and found no incidents in the operation resulted from inadequate systems within our procedures. It did, however, recommend several improvements to strengthen our procedures.
“We will be reviewing and improving our procedures for aerial pest control operations.
“We will direct staff to track performance standards and consent conditions to ensure compliance. A more comprehensive project management approach will also be adopted for operations.”
The review found staff carrying out the operation had overlooked the requirement not to allow people on the track in a well meaning attempt to address the concerns of a local lodge about the impact of closure of the track on its business.
The review concluded the detachment of a bait spreader bucket from a helicopter inside the operational area earlier in the day had contributed to the accidental fall of bait into the track area. It caused delay and disrupted the flying schedule.
Worsening wind conditions were also a factor. It appeared baits were carried further than expected in the wind during the aerial application.
The pest control was carried out over about 4300 hectares of mostly DOC-managed reserves around Mt Stanley. Monitoring showed the operation reduced rat and stoat numbers to undetectable levels and possums to low numbers. Preliminary results from DOC research in the area show robin nesting success increased more than three-fold inside the operational area after the operation, from 22 percent to 78 percent.