Automated Environmental DNA (eDNA) Sampling Using an Optimized Filter Cassette for High Volume Filtration

An automated water sampling device was developed to collect environmental DNA (eDNA) in aquatic environments with minimal human intervention. Dartmouth Ocean Tech-nologies Inc. (DOT) and NatureMetrics have collaborated to produce an eDNA Sampler equipped with NatureMetrics filters to achieve higher volume filtration. The “DOT-NM eDNA Sampler” demonstrated significantly improved filtering capabilities during benchtop testing when tested in parallel with a standard DOT eDNA Sampler loaded with comparable filter membranes. After benchtop testing, the unit was deployed for a 5-day period in Portchester, UK. A parametric study was performed using different sampling volumes: 1 L, 2 L, and 5 L. Results show that significantly-larger volumes are possible before filter clogging. Metabarcoding analysis of samples revealed a similar number of eukaryotic species detected for each of the three tested volumes. The same analysis, however, revealed a positive correlation between the number of vertebrates detected and the sampled volume. This result highlights the benefit of higher filtration volumes when using environmental DNA sampling to identify vertebrates in an environment.