Waiheke Island is set to become the world's largest predator-free urban island under a bold new $11 million plan to rid the Hauraki Gulf Island of rats and stoats.
Millions of passengers visit the Auckland tourist destination each year and the head of Fullers ferry company says it will be extremely difficult to introduce biosecurity measures similar to those imposed on other pest-free islands which involve checking visitors' gear, ensuring food is in sealed bags and cleaning footwear.
Conservation Minister Eugenie Sage will today announce plans to make the island, which is already free of possums, free of other pests by 2025.
This would enable North Island kākā, kākāriki, kererū, tūī, korimako or bellbird, piwakawaka or fantail, tūturiwhatu or New Zealand dotterel, ōi or grey-faced petrel and kororā or little blue penguins to breed safely and increase in number on Waiheke, she said.
Successful eradication of stoats and rats from Waiheke would make it the world's largest and most populated island predator eradication project
The plan is not without its challenges, including how to impose biosecurity checks on 2 million visitors - returning residents as well as tourists - who travel to and from the island by ferry each year, plus those from thousands of recreational boats.
Waiheke Island, which covers 9200ha with a permanent population of about 9000 residents, is a jewel in the Hauraki Gulf and named one of the world's best regions in Lonely Planet's Best in Travel 2016.
"Successful eradication of stoats and rats from Waiheke would make it the world's largest and most populated island predator eradication project," Sage said.
The first stage of the project is focused on removing stoats by traps, followed by a trial on rats to prove the methods will work before they are scaled up.
One environmentalist, who did not want to be named, questioned whether trapping could eradicate stoats and rats over such a large area. It would be better to trap predators in the urban west of the island and carry out an aerial poison drop in the rural east, said the environmentalist.
Sage said traps have been used to eradicate stoats on islands the size of Waiheke in Fiordland. Rat eradication had not occurred in urban centres like Waiheke, but a similar project was planned in the Orkney Islands in Scotland on a bigger island but nowhere near a major city like Auckland, she said.
Sage said a predator-free Waiheke will see the return of native birds from neighbouring predator-free islands.
"We are already starting to see this happen with the recent return of North Island kākā to Waiheke," she said in a statement.
The project, Te Korowai o Waiheke: Towards Predator Free Waiheke, will be launched at Piritahi Marae on Waiheke today.
Auckland Council, Predator Free 2050 and Foundation North are providing the bulk of the $10.9m funding for the project. Other funding, current services and in-kind support is coming from community groups, existing Department of Conservation and Auckland Council programmes and Waiheke landowners.
"The Waiheke project is a wonderful example of how agencies and the community are working together to reduce predators with the goal of freeing New Zealand of possums, rats and stoats," Sage said.
The project will not seek to deprive Waiheke residents of pets such as dogs and cats, despite their ability to kill native wildlife.
"It encourages residents to be responsible pet owners and wholeheartedly supports the organisations on the island working in this area including Hauraki Gulf Forest & Bird and Waiheke Island Society for Care of Animals," Sage said.
Visitors to the island will also not notice any changes until the project reaches a point where the predator-free status needs to be protected.
"Most boaties support the Treasure Islands campaign, which is a joint initiative between DoC and Auckland Council to help protect conservation islands in the Hauraki Gulf. This campaign is well-known to the boating community and helps to ensure we all play our part to guard these special places.
"In terms of the ferry, the team will work with the council and operators when it gets to a point that measures are needed," Sage said.
Fullers chief executive Mike Horne said the ferry company is keen to be part of the predator-free solution, but it presents a few challenges that need to be worked out.
He said Fullers already undertakes full biosecurity measures on trips to Tiritiri Matangi and Rangitoto islands that involves checking visitors' gear for pests, ensuring food is in sealed plastic bags and cleaning footwear and clothing to remove soil and seeds.
Imposing those measures on Waiheke would be extremely difficult with 2 million passengers going back and forth to the island every year, most of whom are residents, he said.
Horne said there are many ways to reach the island and the hard part to control is recreational boating that requires education.
Waiheke landowner Sir Rob Fenwick has been doing pest control on his own land for many years.
"Waiheke is already a jewel in the Auckland region's crown and it will become an even greater taonga once it is the world's first populated, urban island to be predator-free," he said.
Auckland Mayor Phil Goff said Auckland Council was committed to restoring native bush and protecting native birds from extinction.
"We have made fantastic progress in replanting our gulf Islands with native trees and growing our endangered bird numbers such as takahē, kiwi and kōkako.
"Our ambition is now to make our first urban island, Waiheke, predator-free and restore the bird life that once populated the island."
Predator Free 2050 chief executive Ed Chignell said Waiheke was the fourth project to receive backing from Predator Free 2050.
"This will add extra magic to the Hauraki Gulf Marine Park and marks a significant step in the journey to a predator-free New Zealand."