Transport Distance of Invertebrate Environmental DNA in a Natural River
Citation
Deiner K, Altermatt F (2014) Transport Distance of Invertebrate Environmental DNA in a Natural River. PLoS ONE 9(2): e88786. doi:10.1371/
journal.pone.0088786
Summary
Environmental DNA (eDNA) monitoring is a novel molecular technique to detect species in natural habitats. Many eDNA studies in aquatic systems have focused on lake or ponds, and/or on large vertebrate species, but applications to invertebrates in river systems are emerging. A challenge in applying eDNA monitoring in flowing waters is that a species’ DNA can be transported downstream. Whether and how far eDNA can be detected due to downstream transport remains largely unknown. In this study we tested for downstream detection of eDNA for two invertebrate species, Daphnia longispina and Unio tumidus, which are lake dwelling species in our study area. The goal was to determine how far away from the source population in a lake their eDNA [...]
Summary
Environmental DNA (eDNA) monitoring is a novel molecular technique to detect species in natural habitats. Many eDNA
studies in aquatic systems have focused on lake or ponds, and/or on large vertebrate species, but applications to
invertebrates in river systems are emerging. A challenge in applying eDNA monitoring in flowing waters is that a species’
DNA can be transported downstream. Whether and how far eDNA can be detected due to downstream transport remains
largely unknown. In this study we tested for downstream detection of eDNA for two invertebrate species, Daphnia
longispina and Unio tumidus, which are lake dwelling species in our study area. The goal was to determine how far away
from the source population in a lake their eDNA could be detected in an outflowing river. We sampled water from eleven
river sites in regular intervals up to 12.3 km downstream of the lake, developed new eDNA probes for both species, and
used a standard PCR and Sanger sequencing detection method to confirm presence of each species’ eDNA in the river. We
detected D. longispina at all locations and across two time points (July and October); whereas with U. tumidus, we observed
a decreased detection rate and did not detect its eDNA after 9.1 km. We also observed a difference in detection for this
species at different times of year. The observed movement of eDNA from the source amounting to nearly 10 km for these
species indicates that the resolution of an eDNA sample can be large in river systems. Our results indicate that there may be
species’ specific transport distances for eDNA and demonstrate for the first time that invertebrate eDNA can persist over
relatively large distances in a natural river system.
