Courtesy Photo Sam Silverbrand, geneticist with the U.S. Fish and Wildlife Service, samples for lake sturgeon eDNA in the Sandusky River in 2022 in this photo provided by the Fish and Wildlife Service’s Northeast Fishery Center. Silverbrand also collected eDNA samples this year for the project.

ALPENA — In May, Alpena’s Fish and Wildlife Conservation Office sent its native species crew to the southern part of the state to help with a large project run by the U.S. Fish and Wildlife Service.

The crew was looking for the threatened lake sturgeon — but not in the traditional catch-and-release way.

Instead, the Fish and Wildlife Service utilized eDNA, or environmental DNA, to detect lake sturgeon populations in a variety of rivers.

Some of those rivers are located in Michigan, such as the Detroit and Raisin rivers, while others are in neighboring states, such as the Portage River in Ohio and the Niagara River in New York.

The DNA is collected through water samples that eventually make their way to the Northeast Fishery Center located in Lamar, Pennsylvania.

Meredith Bartron is the project leader for the study. She said the researchers are collecting the new way in hopes of detecting sturgeon populations in areas they previously haven’t been able to.

“A number of the rivers have been surveyed with traditional gear over the last 10 to 15 years,” she said. “But no lake sturgeon were detected. We wanted to use environmental DNA as another way to potentially detect the DNA from lake sturgeon in those rivers.”

Bartron said the benefit of eDNA sampling is that crews don’t have to physically find the fish.

Instead, they take water samples, which go through a filtration system. The filters pick up anything from fish scales to feces to mammal hair and are sent back to the lab. At the lab, Bartron said, researchers use something called molecular markers, which narrows their search to just lake sturgeon DNA, as opposed to any other organism’s DNA caught in the process.

Samantha Silverbrand is a geneticist involved in the project, and she goes out into the field to collect every year. She said that, while the collection itself is not difficult, verifying its validity is.

“The tricky part about eDNA is just that you can’t actually be sure of where the source is coming from,” she said. “It could be a physical sturgeon in the water or it could be from accidental transport by boaters, by our teams, from dead organisms … It can even be transferred by other organisms that have eaten that sturgeon.”

To prevent that pollution of the samples, Silverbrand said, the teams look for a “true signal,” and they do that by comparing the eDNA with controlled water samples and with molecular markers. Comparing helps the team sort out which samples are from lake sturgeon and which aren’t, as well as whether the samples may be coming from their own boats or true to the area.

In 2023, the study revealed lake sturgeon populations detected in Michigan’s Detroit River and River Raisin. Silverbrand said the 2024 samples are still being reviewed and samples are still being collected until July.

Once results are in, teams will return to the areas where eDNA was detected to do traditional catch-and-release studies.

Bartron said “eDNA is a really powerful tool. It can be used in conjunction with these traditional fishery sampling techniques to learn more and increase our knowledge about distributions of species and then target where fish might actually be.”

This story was produced by the Michigan News Group Internship Program, a collaboration between WCMU Public Media and local newspapers in central and northern Michigan. The program’s mission is to train the next generation of journalists and combat the rise of rural news deserts.