Citizen sturgeon scientists help study St. Croix’s special fish

Tagging hundreds of fish, volunteer anglers provide priceless data as feds consider conservation options.




9 minute read

Charlie Vaughan and Elana Hansen with three sturgeon caught at the same time on Lake St. Croix. (Photo courtesy Elena Hansen)

Elena Hansen picked a bad time to move to Minnesota, coming to the state from Colorado in January 2020, just in time for the COVID-19 pandemic. It made it hard to make new friends, or to experience so much of what the state offers. But it helped her forge a relationship with ancient fish swimming in the St. Croix and a handful of nearby waters, and then to reciprocate by making a significant contribution to scientific understanding of the species.

This year, Hansen has been part of a volunteer project in partnership with the Wisconsin Department of Natural Resources, in which avid sturgeon anglers on the lower St. Croix help tag and track the river’s population of the special fish. It’s a project of pure passion.

“I love these fish. They are my lifeblood,” Hansen says. “I love how they look. I love how they act. I love hearing about them. I love studying them.”

She gives credit to Theo Birkholz for taking her sturgeon fishing her first time, and brothers Ben and Zach Nagel, and Charlie Vaughn for partnering with her on the tagging effort.

Technical work like this takes a lot of time for over-stretched DNR staff, while it’s also something that requires training and dedication on behalf of volunteers. Hansen and her crew both insert tiny radio tags that can be detected by several sensors placed in Lake St. Croix, and attach external tags that can be reported by anglers when they catch a fish. It helps provide a lot of important information to ensure the fish population stays healthy.

“With our current workload and staffing limitations, it would be very difficult for us to tag this many sturgeon within that time frame,” Yallaly said. “The data they are collecting for us … will allow us to better understand sturgeon population demographics, including recruitment and growth, as well as fish movement within and outside of the St. Croix River, and ultimately aid in future management decisions.”

Expanded effort

Wisconsin DNR staff netting sturgeon at the St. Croix Falls dam. (Courtesy Kasey Yallaly)

Since 2015, the Wisconsin DNR has tagged about 600 fish in the lower St. Croix. Between 2013 and 2017, the Minnesota DNR tagged 714 sturgeon. In the past few months, Hansen and her partners tagged more than 450 — a feat that Yallaly calls “amazing.” Each additional fish tagged improves understanding of sturgeon movements, habitat, and estimates of the population size.

Hansen says she has been fishing nearly as many hours this year as she has put in at her day job.

“It’s essentially a full-time job to spend on the ice and on the water,” Hansen says. But she says it’s worth the work on behalf of a fish she has come to love over the past couple years. The professional process engineer loves the fish, can’t get enough of catching them, and has the attention to detail needed for the work.

Her experience running a cat rescue organization in college provided skills in microchipping that she uses to place the internal tags, while time working at Walmart taught her how to use the price tag tool that is exactly what they use for attaching the external tags.

“It was hard to start doing, I hate hurting the fish,” Hansen says. But she has also re-caught fish she recently tagged, and seen how the tagging site was clean and healed, with no permanent damage.

The tagging effort has additional urgency right now because the U.S. Fish and Wildlife Service is considering a petition to list lake sturgeon on the Endangered Species List, which could affect their future management and angling opportunities. Improving knowledge of the numbers of sturgeon in the St. Croix could help make the right decision.

There are other research efforts afoot, as well. In 2015, the Wisconsin DNR resumed annual sturgeon netting just below the St. Croix Falls Dam. Many sturgeon accumulate here in the spring, and the DNR uses it as an opportunity to assess the species. It’s also when they have tagged numerous fish that have provided informative tracking data.

Meanwhile, the Minnesota DNR has tagged hundreds of sturgeon in the Kettle River, where a population seems to reside that rarely ventures into the St. Croix. But many questions remain.

Yallaly gave a presentation on the Wisconsin DNR’s St. Croix sturgeon research in October at the St. Croix Research Rendezvous, sponsored by the St. Croix Watershed Research Station. She shared that the capture, tag, release method had already offered interesting insights into the secretive sturgeon. For example, two different fish swam all the way from St. Croix Falls to Prescott — fifty-three miles — in three days. Another fish swam from St. Croix Falls to Lake Pepin on the Mississippi River, then bounced back and forth between the Stillwater area and St. Croix Falls. All told, it covered at least 164 miles over one-and-a-half years.

Minnesota migration

A sturgeon getting measured as part of the population monitoring project. (Courtesy Elena Hansen)

Hansen’s work has been so prolific that it caught the attention of the Minnesota Department of Natural Resources this fall. After the presentation on the project at the Research Rendezvous, Matt Ward of the Minnesota DNR’s Hinckley office contacted Hansen about starting a similar project on the upper St. Croix — above the dam. They hope to have it kick off next spring. Ward says the project could provide critical information about what parts of the river sturgeon use throughout the year, and help ensure the habitat is protected.

“Through angler tagging data, we can have an angler catch a fish and plot its movement over time,” Ward says. They’ll try to tag numerous fish this spring, and then use the tags to track them. “Those fish are going to disperse, we can learn a lot about movement based on where they are caught in September or through the year.”

He points out that the potential sturgeon habitat includes the seventy miles of the upper St. Croix, fifty or sixty miles of the Kettle and Snake Rivers, and tributaries on the Wisconsin side. It’s a lot of water, and sturgeon are probably using different stretches at different times of the year, and different stages of their lives.

“That’s a huge area that sturgeon could exist in,” he says. “Little ones might hang out in totally different habitat than big ones, and different spots by season.” The volunteer effort could complement the Hinckley office’s ongoing work, focused more on the young juveniles that are not likely to be caught and tagged by anglers.

Another key question is what size sturgeon are in the upper St. Croix when they reach maturity, or reproductive age. Knowing more about that could help set effective regulations.

Ward points out that projects like this could help both anglers and fisheries managers. Anglers get a better idea of where fish can be found, and the agency gets valuable information.

“We can learn about where fish move throughout the year, because it helps anglers in their pursuit of fish, and helps us understand habitat and population status,” Ward says.

The upper St. Croix project is currently seeking volunteers to start next spring. It’s really a potential project for people who fish for sturgeon a lot, as it takes skill and training, and the DNR needs to tag numerous fish for useful data. Interested individuals can contact Ward at 320-384-7721 or

Endangered debate

While sturgeon were wiped out in many rivers during the nineteenth and twentieth centuries by over-fishing, pollution, and dams, they have rebounded in the St. Croix with careful protection and management in the past few decades. But, sturgeon are still absent from many of their historic habitats. It’s estimated the current sturgeon population is only one percent of what it was historically.

That’s why the Center for Biological Diversity petitioned the federal agency to consider Endangered Species Act protections for sturgeon in 2018, and successfully sued the agency in 2020 to speed up the process. It is now expected to be completed next year.

“We look forward to a decision on endangered or threatened status, which would provide a huge benefit to these swimming fossils known as lake sturgeon,” said Jeff Miller, a senior conservation advocate at the Center for Biological Diversity. “Sturgeon are ancient survivors, but they need our help to adapt to climate change and deal with past damage to their river and lake habitats. We need to remove key dams to allow sturgeon to repopulate more of their former rivers.”

While the petition seeks to have all of the United States’ sturgeon protected, the Fish and Wildlife Service has the opportunity to considered different rivers and river systems as having distinct populations, and can decide to list only some of them.

For the St. Croix and its tributaries, the Center for Biological Diversity cited the results of sturgeon surveys and population estimates from the 1960s to 2014. The references only include the population on the upper river, not Lake St. Croix. They also point to population estimates and past research on upper river tributaries including the Snake, Kettle, Namekagon, and Yellow Rivers.

Surveys between 2004 and 2010 by the Wisconsin DNR turned up fewer than a thousand sturgeon over twenty-one inches in length in the upper seventy miles of the St. Croix.

“It should be noted that a substantial portion of the population estimate was comprised of juvenile fish,” the Center for Biological Diversity wrote. “These population levels are below the lower limits for a self-sustaining population and an estimated survival rate of only 59% does not provide much hope for population recovery. Wendel and Frank also found that St. Croix River lake sturgeon were highly catchable, recommending that the lake sturgeon recreational fishery remain closed to prevent rapid population decline.”

It’s easy to see why more and newer data is needed. Not enough is known to really determine the present health of the population, nor the impact of angling and other human activities.

In a St. Croix 360 article published in 2021, the Minnesota DNR’s Joel Stiras said the best estimate he has come up with points to a sturgeon population in Lake St. Croix of nearly six thousand. And Stiras said he believes it “greatly underestimates” the real number.

Hansen says the lower St. Croix’s sturgeon population is healthy enough to handle current angling activities. Allowing fishing creates more people who know and love the fish and will be dedicated to their conservation.

“For them to list it as endangered would be a huge blow to the sturgeon fishing community and doesn’t really make sense,” she says. “Yes, they may be endangered in areas that have not recovered. And that is unfortunate, but to straight up say we wish to not have any angling whatsoever in the entire United States just is kind of absurd.”

From the Mekong to the St. Croix

Elena Hansen with one of the sturgeon she loves. (Courtesy Elena Hansen)

Hansen has had a long and winding road to the St. Croix and its sturgeon. Adopted from Vietnam as a child, it caused a lot of turmoil in her younger years. But she believes she was born to fish. “My mother was a poor farmer in the Mekong Delta,” she says.

She also grew up watching Jeremy Wade on his television show “River Monsters,” in which the British angler travels the world catching huge fish. That includes white sturgeon in the Pacific Northwest, gentle giants that Hansen grew up dreaming about catching.

Then she moved to Minnesota and made the discovery she could catch sturgeon close to home.

“‘I don’t know how the hell I’m going to do this, but I want to give it a shot,’” Hansen thought. “Sturgeon was something you catch once in a lifetime in my mind.”

She spent thirty hours on the St. Croix ice her first week, and finally got her first one, a forty five-inch specimen — unremarkable for a sturgeon, yet the biggest fish Hansen had caught in her life to that point.

“I didn’t expect to catch one,” she says. “I thought they’d be super rare. It turns out they’re not super rare.”

Later, she caught one sixty-four inches long, “one inch shorter than me,” she says. She fell hard for the fish.

The sturgeon’s resiliency have inspired her. She can’t get enough of trying to catch them, and credits the fish with introducing her to new friends, helping her face fears, and motivating her to get outside.

“I relate to them because they came back essentially from brink of extinction, and I really struggled as a child,” Hansen says. “And so that thought of perseverance and that thought of, hey, they came back from extinction, maybe I can too was huge and really made me relate to them in a sense.”

Helping monitor the sturgeon population in the St. Croix is simply a matter of reciprocating.

“I love these fish, if there’s anything I can do to help, especially through my angling efforts, I will jump on that,” Hansen says. And it’s a favor to her future self. She says she’ll always be a sturgeon angler, and there’s a chance that in fifty years, she’ll catch one of these long-lived fish that she tagged at this time in her life.


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3 responses to “Citizen sturgeon scientists help study St. Croix’s special fish”

  1. Jeff Willius Avatar

    I love the passion the sturgeon have kindled in Elena. They are indeed a fascinating, kind of haunting fish. Thanks to her and the other volunteers for their valuable work.

  2. John Engstrom Avatar
    John Engstrom

    Wonderful article. I have never fished for Sturgeon but would like to try sometime. Elena should be really proud of the contribution she has made for this wonderful fish.

  3. Troy Howard Avatar
    Troy Howard

    Well done, Greg!


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Citizen sturgeon scientists help study St. Croix’s special fish