A project to restore islands on a lake in Te Urewera National Park to their pre-European state is showing positive results.
Rodent bait has been spread on five islands on Lake Waikareiti, the smaller neighbour of Lake Waikaremoana, in an attempt to make them pest-free.
A total of six islands are free of possums and home to rare flora species, and DOC staff - along with dozens of volunteers - have been spreading pellets in a bid to make them completely pest-free.
Department of Conservation services ranger, Brown Elia, says the pellets are targeted to rats and mice which swim across the lake to the islands.
The bush being trekked through is quite dense and requires considerable effort to push through to ensure the entire island is covered by the rodent bait.
About 40 to 50 people from across Bay of Plenty have been involved in the pellet-spreading.
Te Urewera National Park's conservation services manager, Hemi Barsdale, says a reasonable amount of fitness has been needed.
The rangers are aiming for even more dense vegetation coverage on the island to impede the movements of potential predators.
Newton Lambert is from Ngai Tuhoe, Ruapani and Nga Potiki and is one of the kaumatua for Lake Waikaremoana.
He says the work they're doing means they are looking after their whanau; the trees and the birds.
The biodiversity assets ranger Sandra Elia says on this island, Te Kahaatuwai, there are three species of endangered beech mistletoes.
Ms Elia says there is another island on the lake but it is too close to the mainland for the type of poison used in the pellets.