WELLINGTON, Nov. 28 (Xinhua) -- As rats have been a problem on Cook Islands' Palmerston Atoll for over a century, a rat eradication operation has been conducted with the hope that introduced rats never return to menace the atoll's community and ecosystems, New Zealand's Department of Conservation (DOC) said on Tuesday.
The eradication of introduced ship rats and Pacific rats from Palmerston was performed in a six-week period under the partnership between New Zealand's DOC, the Cook Island's national and local authorities, as well as the Palmerston Atoll community and local non-government organisations.
Rats have been destroying wildlife and eating crops on Cook Islands' Palmerston Atoll, 500 km from the largest island of Rarotonga, for over a century, Palmerston's Executive Officer Arthur Neale said, adding that the problem could become even worse by making people less resilient to climate change impacts.
According to a survey of natural resources on the island, the area's rat situation was grim.
The community did a lot of preparation to ensure the success of the operation, Neale said.
"We couldn't have any food available for the rats - the bait had to be the only option for rats to eat," he said, adding that households had to ensure their kitchen wastewater drainage systems were completely sealed and renewed.
"Some of us cleared bush areas, removed sugar cane from our gardens and removed any fruits from fruit trees and stopped growing vegetables known to be eaten by rats, such as cucumbers," Neale said.
Freezers were used for food storage. People had to put their food scraps in sealed containers. Household rubbish was placed in covered sealed bins for weekly collection to be incinerated by the island administration staff, he added.
Some of the livestock chickens and pigs had to be culled as they might eat the toxic bait. Some households moved some of their livestock to other islets where they were penned. Contained sealed food scraps were collected for feed for chickens and pigs on the islets, Neale said.
"We were thorough and worked together because even a single female rat left alive could mean failure for the whole operation," said DOC's Em Oyston, the project team leader who led the team with international expertise in island eradications.
Tropical environments like Palmerston Atoll can have over 200 rats per hectare as they breed year-round in warmer, more productive environments, experts said.
Ensuring no rodents arrive on vessels or cargo is key to the long-term success of the project, Neale said, adding that even though the operation was over, the work to keep rats off the atoll has just started.
Project partners will assess the operation's results in April 2024 to determine whether the island can be officially declared rat free. ■