Dr Nicholas Foster1, Professor Neil Gemmell2, Dr Shaun P. Wilkinson3,4, Dr Kristen Fernandes2,5, Professor James C. Russell6, Dr Nick Mulgan1
1Zero Invasive Predators, Lincoln / Christchurch, New Zealand, 2Department of Anatomy, University of Otago, Dunedin, New Zealand, 3Wilderlab NZ Ltd, Miramar / Wellington, New Zealand, 4Curtin University, Bentley, Australia, 5Department of Biodiversity, Conservation and Attractions, Perth, Australia, 6University of Auckland, Auckland, New Zealand
Biography:
Nick Foster is an ecologist at Zero Invasive Predators (ZIP), who works in invasive small mammal elimination in mainland sites within Aotearoa New Zealand's South Island.
eDNA sampling has been demonstrated to be a highly sensitive and efficient technique for detecting and monitoring cryptic species and has found its place as a tool that improves biosecurity in many situations.
Abstract:
There is a potential for eDNA collected from riverine environments to revolutionise how the monitoring and surveillance of invasive terrestrial mammal species is conducted. However, the technique has not yet been established in this field, and it is not understood how to best apply it as an emerging practise.
One avenue to advance passive eDNA sampling is the physical sampling methodology with consideration to the environmental conditions in which it is used. In this study, we sought to understand how deployment duration, number of site replicates, precipitation, distance from eDNA source, and river characteristics affect the yield of eDNA of terrestrial taxa from passive samples collected in rivers. We used these findings to develop sampling methodologies for two purposes: for discerning between high, medium and low densities of an invasive rodent (Rattus rattus); and for detecting their populations at very low densities.
In this presentation, I share learnings from a suite of field trials conducted in the mountains and forests of Aotearoa New Zealand's West Coast within the Predator Free South Westland project area, where a range of invasive small mammals are targeted in an elimination programme. This research contributes to a growing understanding of how riverine eDNA sampling is best applied for detecting and monitoring terrestrial species and identifies key areas for further development.