You are here: Home / Research Topics / Research Highlights / Individual Highlight

Research Highlights

Individual Highlight

No Fish Left Behind: Using eDNA Sampling to Inform Fish Eradication Efforts

Photo of eDNA sample collection. Photo by M. Schwartz. - photo
A guide for using eDNA methods to assist invasive fish eradication in streams. From Carim et al, 2020. - imageeDNA sample collection. Photo by M. Schwartz. - photo A guide for using eDNA methods to assist invasive fish eradication in streams. From Carim et al, 2020. - imageSnapshot : Environmental DNA methods are highly sensitive and accurate, making them ideal for detecting animals at low densities. However, this tool also comes with its own unique set of challenges when applied to efforts to eradicate invasive species. This research explores the use of eDNA for evaluating invasive species eradication efforts in streams and offers best practices for incorporating eDNA methods into invasive species removal projects.

Principal Investigators(s) :
Flores, David Carim, Kellie
McKelvey, Kevin S. Young, Michael K.
Franklin, Thomas W.  
Research Location : Northern Region (R1); Montana; Custer National Forest; Gallatin National Forest; Pacific Northwest Region (R6); Washington; Colville National Forest
Research Station : Rocky Mountain Research Station (RMRS)
Year : 2020
Highlight ID : 1717


In streams, chemical piscicides can be an effective tool for eradication of invasive fish. However, chemical treatments are expensive, time consuming, and do not discriminate between invasive and native species in a system. To reduce project costs and biological impacts to the native community, an eradication project ideally would treat the entire area occupied by the non-native species, avoid areas where non-native species are absent, and eliminate all target individuals in one treatment. Highly sensitive methods for detecting animals in low abundance are needed to support this careful targeting.  We studied how environmental DNA (eDNA) sampling addressed these challenges through three case studies, each of which used eDNA sampling to inform removal of Brook Trout (Salvelinus fontinalis) in small streams. We found that eDNA methods can be informative throughout all stages of eradication projects in stream settings. They can assist with delimiting the population prior to treatment, provide detailed location data on surviving target individuals, and serve as an efficient and relatively inexpensive monitoring tool to assess long-term treatment efficacy. When combined with traditional survey tools, such as electrofishing, eDNA sampling may help reduce the size and number of treatments necessary to reach project goals. This translates directly to increased efficacy of treatments, reduced labor and cost, and reduced impact on native species.

Forest Service Partners

External Partners

  • Bill Baker - Washington Department of Fish and Wildlife
  • Jason Connor - Kalispel Tribe of Indians
  • Matt Jaeger - Montana Fish - Wildlife and Parks
  • Mike Ruggles - Montana Fish - Wildlife and Parks
  • Nick Bean - Kalispel Tribe of Indians