Environmental DNA

What is environmental DNA?

Environmental DNA, commonly called eDNA, is DNA that is shed from organisms in the natural environment. Skin cells, mucus, urine, and feces all contain the signature DNA of the animal that shed them. Everywhere animals go, they leave a trail of eDNA behind. As a result, using cutting-edge genetics techniques we can sample eDNA in streams to determine, with confidence, whether fish species of interest were present upstream from the sample site, or were there within the week preceding the sampling event.

This requires having DNA from the target species, against which the sampled eDNA is compared in a laboratory. The DNA ‘library’ from target species in the Pacific Northwest is growing rapidly as eDNA becomes more widely used by researchers to better understand the distribution of fishes.

A Noninvasive Research Tool

Environmental DNA allows you to non-invasively test for the presence or absence of any species with a high degree of accuracy, and compared to traditional approaches like electrofishing, snorkeling, or seining, eDNA is much more effective at determining the

presence of rare or cryptic species.

Because the fieldwork simply requires filtering stream water, eDNA assessments are done without handling the target species – an important consideration when working with populations of threatened or endangered fish. It has revolutionized researchers’ ability to understand fish species distribution at the landscape-scale.


Understanding where threatened and endangered fish live is fundamental to efforts to effectively protect and restore the habitats they rely upon. This, along with hatchery and harvest reform, provides a recipe for recovery.

Our Initaitives

Since 2015 Wild Fish Conservancy has been using eDNA in a variety of projects throughout Washington. With this powerful tool we are also searching for previously undocumented bull trout populations in Olympic Peninsula headwaters and Wenatchee wilderness tributaries, and mapping fish distribution in San Juan County watersheds.


Wild Fish Conservancy partners with the US Forest Service’s Rocky Mountain Research Station to complete eDNA laboratory analyses of water samples from watersheds throughout Puget Sound. These species of interest range from endangered salmonids and salmon indicator species to sculpin and other common aquatic species.

Related Projects

Beaver Dam Analogs

Beaver Dam Analogs are simple artificial structures designed to mimic the form and function of natural beaver dams. They are built into existing wetlands and channels to encourage channel rejuvenation and support beaver reintroduction.

Help Conserve the Northwest's Iconic Wild Fish

Lorem ipsum dolor sit amet, consectetur adipiscing elit.