Modeling the spread of environmental DNA passing through heterogeneous environments
- Funded By: Notre Dame Environmental Change Initiative
- ECI Investigators: Christopher Jerde, Diogo Bolster, Jennifer Tank, Brett Olds
The use of environmental DNA as a conservation tool to identify the presence of aquatic species is predicated on the idea that sloughed tissue from an organism is held in suspension and then collected in a water sample, thus revealing the presence of the target organism in close proximity. However, in flowing water systems, the target organism may be some distance away from where the eDNA is collected in a water sample that ultimately came from upstream. As such, resource managers are faced with the problem of interpreting the positive detection eDNA from a species that resides in flowing waters: Is the species nearby or is the eDNA from an organism some distance upstream? Residence time of eDNA in a watershed is unknown beyond limited degradation studies conducted in non‐flowing experimental mesocosms.
This study of eDNA residence and travel time uses empirical data from controlled laboratory columns as well as experimental watersheds at the field‐scale. The results from ND-LEEF were critical for delimiting the extent of potential invasions or the distribution of threatened and endangered species, in addition to facilitating the estimation of the area over which species richness estimates can be made.