The islands of the Hauraki Gulf are to be the focus of a research project to find ways to keep them free of pests.
About half of the islands still contain pests and Auckland Council says they are all under a significant threat from stoats.
Auckland University PHD student Andrew Veale is to research the predators' migration patterns, to determine where they are coming from, and if they are swimming or stowing away on boats between islands.
He says genetic material from the stoats will enable him to determine how often they move between islands and the threat they pose.
The project will take two years.