Environmental DNA (eDNA) metabarcoding of pond water as a tool to survey conservation and management priority mammals in the UK

Environmental DNA (eDNA) metabarcoding is used to survey amphibian and fish communities, but can also reveal terrestrial taxa utilising freshwater habitats. However, the entry and dispersal of terrestrial species DNA in water remains ambiguous. We evaluated eDNA metabarcoding for monitoring conservation and management priority mammals in the UK, and examined the spatial distribution of mammal eDNA in ponds. Directed (by behavioural observation) and random (equidistant intervals around waterbody) water samples were collected from focal species enclosures at two wildlife parks. We surveyed natural ponds (N = 6) where focal species were present using random water sampling, camera traps, and field signs. Extracted eDNA samples (N = 220) were screened for all vertebrate species using a two-step PCR protocol to amplify the 12S ribosomal RNA (rRNA) region, followed by High-Throughput sequencing on an Illumina MiSeq. Our results show that eDNA metabarcoding could be implemented in mammal monitoring schemes and enable large-scale, multi-species distribution assessment.