Skip to main content
Premium Trial:

Request an Annual Quote

Floating Down the River

Wildlife biologists are using environmental DNA to track fish, aquatic plants, and other species as they move through streams and rivers, NPR's The Salt blog reports.

Shaun Clements from the Oregon Department of Fish and Wildlife tells NPR that the state has so many waterways that it can't monitor them all for invasive species or check up on native species. However, measuring eDNA — DNA shed by organisms in the rivers or streams — may make that easier.

"Just by taking a water sample, you can tell somewhere in basin above you, there was this range of species and something about their relative abundance," Clements says.

But first researchers have to figure out how factors like water speed, sunlight, and bacteria levels, among others, influence the amounts of eDNA they pull out of the water. Clements and his colleagues have been adding small amounts of synthetic DNA to a waterway at one point and racing downstream to see how much of that — if any — they can detect at various other spots.

"There was a lot of DNA in there — trillions of DNA particles. But that was being diluted into millions of liters of this stream," Kevin Weitemier, also from the fish and wildlife department, tells NPR. "So we might only recover a very small proportion."

The results, Clements adds, will help them figure out how to use eDNA as a monitoring tool.