Hunua Project: 1080 pest management
In August and September 2015, Auckland Council aerially applied 1080 (sodium fluoroacetate) to around 21,500ha of parkland and some private land in the Hunua Ranges area.
The operational part of the programme is now complete and the parks reopened in late 2015. The caution period was lifted in April 2016.
To contact Auckland Council’s Hunua project team, phone us on 09 301 0101 or send us an email.
Why did we do this?
In the last few years, possum and rat numbers increased significantly in the Hunua Ranges. This was having a severe effect on the health of our forest and threatened species, like kōkako, that live within it.
Pest control methods being used were no longer effectively controlling pests so we were faced with an important decision. As a result, the way we manage pests in the Hunua Ranges, Waharau and Whakatiwai regional parks was changed to include the aerial application of 1080 bait.
Preparing to apply 1080
It took almost a year to plan and implement the operation and involved working with a number of organisations, groups and the people that live and work in the Hunua Ranges area.
We were granted permission to apply 1080 by the Auckland Regional Public Health Service (ARPHS), which set conditions to protect human health. ARPHS helped us plan the track clearance programme and worked with Watercare on the drinking water monitoring plan.
We worked with the Department of Conservation (DOC) to include its Mangatawhiri Forest Conservation Area and Vining Scenic Reserve in the operation, and also drew on DOC’s expertise in this pest management methodology.
All landowners or occupiers that live adjacent to the parkland were contacted, and many visited, before the operation.
Around 3000ha of private land was included in the operation and residents helped us establish exclusion areas or gather important information on water takes and stock requirements.
Working with mana whenua
Kei roto ngaa ringa ote ira taangata te kaitiakitanga me te maaramatanga hei oranga mo Te Waonui o Taane Mahuta.
It is in our hands, the guardianship and the enlightenment to sustain and look after the vast realms of Tane.
The Hunua Ranges and Kohukohunui are extremely important to seven iwi with tribal ties to this area. Council and mana whenua have a common goal – protecting this forest – and it was important to work side-by-side with iwi on the kaitiakitanga of the ranges.
Representatives from Ngai Tai ki Tamaki, Ngati Whanaunga, Ngati Paoa, Ngati Tamaoho, Te Akitai, Ngati te Ata and Ngati Maru were involved in many aspects of the operation, with representatives also participating in the track clearance and cultural water monitoring programmes.
More than 200 staff, contractors, partners and iwi representatives took part in the operation. A highly accurate satellite navigation system (GPS) and custom-designed bait applicators were used to distribute bait (by helicopter) across the 21,500ha operational area.
To reach as many target species as possible, a two-step method was used.
Step one was a non-toxic pre-feed to familiarise pest animals with the cereal baits and make them hungry for more.
Step two was the application of baits containing the 1080 (sodium fluoroacetate) toxin.
In order to manage such a large area and to take extra care around the water supply reservoirs, the operational area was divided into two blocks.
The Cossey and Mangatangi catchments were treated as one block, and the Wairoa and Mangatawhiri catchments treated as another.
30 July 2015 - pre-feed of block one with non-toxic cereal baits
21 August 2015 - 1080 applied to block one and pre-feed of block two
14 September - 1080 applied to block two
21 September - parkland reopened
Each hectare received around 2.5kg of cereal pellets, containing 0.15 per cent of the active 1080 ingredient. That’s about one teaspoon of 1080 per hectare.
The parks were closed during the operation and a track clearance programme carried out before they reopened.
Carrying out this operation in a water catchment area required careful planning and working closely with Watercare. More than 270 water samples were tested, with no 1080 detected.
Important measures were put in place to ensure the ongoing safety of Auckland’s water supply, including:
- no flying over water supply reservoirs
- exclusion zones around reservoirs where no bait was applied
- using highly accurate (GPS) application technology to apply bait
- returning reservoirs to service only after a rigorous water-testing schedule was complete
- working with landowners to understand drinking water extraction from streams flowing out of the operational area.
What happens next?
We have lifted the caution period that applies after a 1080 operation, and have taken down warning signs. Information signs remain in place and we are continuing to monitor pests and species.
Within a few months of the last bait application, monitoring results were astounding with the lowest-ever recorded figures for rats and possums (including zero per cent in the intensively pest-controlled kōkako management areas).
Read more about the monitoring results on OurAuckland.