PolyWAG: Autonomous filtered water sampling for eDNA

Abstract

Environmental DNA (eDNA) is an ideal way of researching aquatic environments and determining what species are present in an area the biodiversity of an area, and if any invasive or endangered species are present. Traditional sampling of eDNA consists of manually filtering water, which is labor and cost-intensive for remote locations. Furthermore, commercialized solutions are either expensive or require a field operator to function. We have built a battery-powered eDNA sampler capable of autonomous multi-sampling for a greatly reduced price compared to existing technologies. Environmental DNA collection contains 3 main components: environmental DNA must be preserved, the filtered volume must be accurate, and there must be no cross-contamination between samples. The sampler operates in this way separating eDNA via filters, preserving DNA, and recording the filtered volume per sample. Our PolyWAG eDNA sampler system is a water sampling device that collects DNA samples via 47 mm filter and provides a non-invasive, safe and autonomous means of eDNA collection. The sampler can hold 24 filters and is designed to be easily replaced and reusable. A browser application is used for real-time monitoring, scheduling tasks, and data logging for time, pressure, flow, and filtered volume. Additionally, the sampler design is openly published, modular and is constantly being tested to help us optimize our software and hardware to give us the best results. The 13-step sampling sequence helps reduce cross contamination significantly. Our machine can be deployed for an extended period. It is completely autonomous and costs around $3800 for components or $6000 including labor.