KEY POINTS:
An aerial rat-poisoning campaign could soon be launched to restore the beauty spots of the eastern Bay of Islands to their natural state.
The project aims to exterminate rats and stoats and allow endangered birds, plants and lizards to thrive again on the Ipipiri group, which lies between Russell and Cape Brett.
The seven main islands in the group - Motuarohia (Roberton Island), Moturua, Motukiekie, Okahu, Waewaetorea, Urupukapuka and Poroporo - are among some of New Zealand's most important island archaeological and cultural sites.
But rats and stoats have devastated ecosystems by eating everything from seeds, plants, birds' eggs and chicks to insects and lizards.
To run a two-year island pest eradication project, the Department of Conservation at Kerikeri in the Bay of Islands is working in partnership with community group Guardians of the Bay of Islands and the two Rawhiti-based, eastern Bay of Islands hapu Patukeha and Ngati Kuta.
"When this project is complete, we can see those seven islands being brought back close to where they were 170 years ago," Patukeha spokesman and Guardian board member Richard Witehira says.
"We're totally happy to be involved."
DoC manager for the rodent elimination project, Adrian Walker, says the Bay of Islands community has willingly put its hand up to support the restoration effort.
He believes techniques learned from previously successful rodent elimination projects, like those on Tiritiri Matangi in the Hauraki Gulf, can easily be adapted to the eastern Bay of Islands.
"Eradicating rats has been successful on at least 100 other islands around New Zealand and the department is recognised as a leader in this field," Mr Walker says.
Consent for an aerial poisoning operation, targeting rats by dropping brodifacoum poison, is to be sought from the Northland Regional Council after major stakeholders in the project indicated support for an aerial drop.
Assuming consent will be granted, DoC is looking at a two-week aerial operation between June and September next year, depending on weather.
Although rats will be the principal targets of the brodifacoum, some of the islands' stoat population will also die from secondary poisoning by eating poisoned rats.
Ground trapping and trained dogs will be used to complete the elimination of stoats.
Professor Rachel Fewster, of Auckland University, has conducted a recent genetic study of rodents on the islands and this work is vital to manage any future rat reinvasion.
To minimise the reinvasion risk, a mainland pest control programme is planned in conjunction with the eradication operation.
Project partners say the creation of nearby mainland pest control areas or pest-free buffer zones are critical to keeping the islands free of rodents after the eradication operation.
Rodents and stoats can swim back to the islands from mainland headlands, and they can also arrive with people visiting the islands.
An associated biosecurity project to reduce this risk is being developed..
Mr Walker says DoC is improving its own island biosecurity systems and wants to work with island landowners, boaties, campers and day travellers to ensure rodents don't go back to the islands as a result of human activities.
Community-led pest control is being headed by the Guardians with support from the local hapu, coastal mainland landowners and the regional council.
Success of the eradication project can be confirmed only after two years before the opportunity exists to reintroduce native birds, lizards and plants at present lost to the islands.
Majority of Patukeha iwi agree to poison drop
One big breakthrough in the Bay of Islands conservation project has been a majority agreement from the Patukeha iwi to the aerial poison drop.
Patukeha spokesman Richard Witehira said it happened because this time the Department of Conservation "came from a more informative angle and distributed the necessary information".
In the Far North, the department and Maori have often been at odds over aerially dropped poison baits on land and bush to rid areas of pests, with Maori fearing adverse effects from poison such as 1080 on other wildlife and in streams and waterways used for drinking.
Lynette Smith, chairwoman of the community group Guardians of the Bay of Islands, said the project was "terrific", but would need community and sponsorship support when the islands became free of rodents.
Volunteer programmes will be developed, with buffer zones for pest control on the mainland to help protect the islands.
The Guardians, formed as an incorporated society in March last year, have 60 paid-up members.
Ngati Kuta spokesman Bob Willoughby said their first objective was to clear mainland areas of pests, then attack the islands' rodents.
"You start from the outside and work in. There's a systematic way of doing it."
Mr Willoughby said the main pests were rats. Although there were no possums on the islands, they would be excluded from the mainland buffer zones.
"It's a whole land and sea thing, sustaining an economy," he said.
"It's the nature of the area that visitors come here to see - a cornerstone of tourism."
