Lessons learned from 1080 deaths

Cereal baits laced with 1080 are lethal to mammals, whether they be pests or pets. Picture / Wairarapa Times Age

Local authority investigations into the accidental fatal poisoning of three dogs and two heifers after separate ground-based pest control operations in Northland have recommended system changes to reduce the likelihood of similar future incidents.

The first deaths occurred in the Tanekaha Community Pest Control Area (CPCA)at Mangawhai in late September, when the heifers found their way through 'deteriorated' fencing into an area where possums and rodents were being targeted (as part of a kiwi recovery programme) and ate leftover material in bait stations.

In mid-October three dogs died after a Labrador and a German shepherd apparently scavenged the carcass of a possum that had been killed in a similar operation in the Hukerenui CPCA Community Pest Control Area. The third dog was thought to have died after consuming material vomited by the first two.

Both control operations involved 1080 and were jointly managed by local communities and the Northland Regional Council, the council now having reported the results of its investigations.

Deputy chief executive (and group manager environmental services) Bruce Howse described the cases "unfortunate and highly regrettable."

The council was sorry for the distress the animals' owners had experienced, and had assured them that the incidents were being treated very seriously.

"Both incidents have been very carefully investigated, and the lessons learned will be incorporated into any future operations using 1080, which remains an essential tool of our pest control toolbox," Mr Howse said.

The investigations had found that the heifer deaths in particular were an unfortunate series of events, risks and factors, any of which in isolation would have been unlikely to have resulted in any harm. They included deteriorating fences, 'miscommunication' over toxin removal and the lack of an identified project leader with overall responsibility for the operation. The Tanekaha group had carried out three previous similar operations since its formation in 2012, none of which had raised any issues.

"However, while there were already a number of existing checks and balances, we accept that improvements to current procedures are needed in both cases, and the reviews have recommended a number of changes that will be implemented as a result," he said.

Recommendations included that all council-supported pest control operations using any toxins had a detailed project plan, communications plan and risk assessment to ensure critical details and issues were not missed. Those should also be peer- reviewed before an operation began.

Mr Howse said in the case of the dog deaths, an initial "knockdown" of the significantly high possum populations in the area before the 1080 operation may also have reduced the resulting number of possum carcasses and associated risk to dogs. (The CPCA was only formed last year, focusing on predator control to protect kiwi.)

Both the Tanekaha and Hukerenui CPCA groups enjoyed good support from their local communities, which the council appreciated greatly and was keen to see continue.

"Community pest control areas are useful and productive partnerships between the regional council and community groups interested in restoring Northland's unique environment," he said. Sixty-eight CPCAs, collectively involving more than 1000 people and covering more than 120,000ha, had been established over the past decade.

"These are in parts of Northland that our communities have identified as worth, protecting and the primary focus of most is control of animal pests like rodents, possums and mustelids to preserve wildlife, particularly kiwi, in those areas." Wetland, forest or overall catchment protection/enhancement were also important drivers.