Pacific Northwest
via Oregon State University

OR - Researchers Prove Fish-Friendly Detection Method More Sensitive Than Electrofishing

Delivering a minor electric shock into a stream to reveal any fish lurking nearby may be the gold standard for detecting fish populations, but it's not much fun for the trout.

Scientists at Oregon State University have found that sampling stream water for evidence of the presence of various species using environmental DNA, known as eDNA, can be more accurate than electrofishing, without disrupting the fish.

"It's revolutionizing the way we do fish ecology work," said Brooke Penaluna, a research fish biologist with the U.S. Department of Agriculture Forest Service who also has an appointment in OSU's Department of Fisheries and Wildlife. "You can identify species from a bottle of water using genetic tools. When you go out to the site, I can tell you what's in that stream just based on what's in this bottle of water."

Penaluna is lead author on a study published Wednesday in Ecosphere that compared the efficacy of eDNA sampling and electrofishing in detecting how far upstream coastal cutthroat trout were present in coastal and Cascade streams throughout Washington and Oregon.

Determining how far upstream fish are present is crucial for guiding forest management practices, as streams with fish in them receive more protections than streams without fish. It also helps inform conservation by improving scientists' understanding of specific species' distribution and movements.

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