Vern St. John, left, and Jeremy Hubbard hold a sturgeon on Indian Lake. Researchers are using eDNA to increase sturgeon numbers. (Photo courtesy of the U.S. Department of Agriculture)

GLADSTONE — Researchers from the Hiawatha National Forest and the Northern Research Station are using modern technology to bring back an iconic fish that was nearly wiped out by early 20th-century logging and commercial fishing.

Lake sturgeon are impressive creatures that can grow more than 8 feet long, weigh up to 300 pounds and live more than 100 years. In the late 1800s, there were as many as 15 million lake sturgeon in the Great Lakes. Commercial anglers regarded them as a destructive nuisance, as the large animals would get tangled in their nets and cause damage.

A common solution was to simply kill them on sight and toss them up on the banks, depleting their numbers to less than 1% of their 15 million peak. With such a scarce population, finding the fish these days can be exceedingly difficult.

That’s where eDNA comes in. Environmental DNA, or eDNA, is genetic material that is shed from organisms and then briefly persists in the environment — like pollen in the air from plants, or skin cells in the water from fish. Because researchers only need an environmental sample from the surrounding air, water or soil to obtain it, eDNA is ideal for finding hard-to-find animals like lake sturgeon.

A few years ago, Eric Miltz-Miller, a fisheries biologist with the Hiawatha National Forest, approached the Northern Research Station about working together to integrate eDNA sampling methods into the forest’s aquatic management and planning.

“I just asked them, ‘Are you guys interested in doing eDNA?'” Miltz-Miller said. “‘It’s kind of the up-and-coming way for managers to find cryptic and difficult to sample species and it’s something that’s going be cutting edge going forward in the future.'”

The timing couldn’t have been better, as Dr. Deahn Donner, project leader and research landscape ecologist with the research station, also looked for partners to begin conducting landscape genetics research using eDNA. Several potential species important to the Hiawatha were discussed, and they ultimately landed on lake sturgeon.

“We chose lake sturgeon because they were extirpated from nearly all of their native waters by logging practices and commercial fishing by the early-mid 1900s,” Miltz-Miller said. “It is now a state threatened species and is petitioned for listing under the Endangered Species Act.”

Both parties then invested in backpack eDNA samplers, and a combined team of researchers conducted a trial run to determine if lake sturgeon were present in the lower portions of the Indian and Sturgeon rivers, where they were historically known to spawn.

The testing was a success, so sampling has been expanded into the Whitefish River and to further upstream reaches of the Indian and Sturgeon rivers. The goal of the project is to paint a clearer picture of where current lake sturgeon populations are concentrated so researchers know where to focus their conservation efforts.

So far, the results hold promise.

“We can say with certainty that not only are there lake sturgeon in the Indian and Sturgeon River systems, but there is actually an adult population that’s trying to run the system and spawn,” Miltz-Miller said. “We can’t say that they are spawning or that they’re successful because we don’t know numbers and we haven’t documented them spawning yet. But we can say for certain they are trying to re-enter that system.”

Donner said joint projects like this one are invaluable for further research and conservation efforts. ”

Through this project, we will increase the state of knowledge for a species that’s in trouble, requiring large-scale planning among many partners,” Donner said. “It’s also exciting for me as a scientist to work with managers and have our results applied, not just to the management of lake sturgeon in the Hiawatha, but potentially to other national forests with similar aquatic systems throughout the northern Lake States. So, it could benefit many other forests going forward.”

The project is the first in what researchers hope to be a long series of collaborative research projects that use eDNA to help protect other species of concern or monitor for early detection of invasive species.