Young scientists contribute to critical studies of lakes and rivers at St. Croix Watershed Research Station

From their home base along the St. Croix River, the next generation of water researchers is making an impact across Minnesota.




8 minute read

This article is published in partnership with the St. Croix Watershed Research Station.

Mari Leland collects material from a North Shore river as part of research into a harmful algae species. (Photo by Greg Seitz)

One afternoon in July, Mari Leland was standing knee deep in the Knife River on Minnesota’s North Shore, scrubbing rocks. On her downstream side, she held a fine mesh net that collected the detritus that came off the rocks as she scrubbed, from algae to tiny insects. The bugs would be brought back to a lab and get their stomachs pumped to reveal what they have been eating. All the material would offer a better understanding of how the stream’s food web was working.

Still early in her science career, Mari is one of many young scientists learning and contributing to important studies at the Science Museum of Minnesota’s St. Croix Watershed Research Station, based in Marine on St. Croix.

Scrubbing the river rocks was just one part of a broad and deep study of how Minnesota rivers flowing into Lake Superior are both similar and different, and how they are changing — including the invasion of a new kind of algae that threatens to upset the ecosystem and recreational activities.

Scientists working at the Research Station study lakes, rivers, and land. They regularly reveal important information about everything from harmful chemicals in water, to the effects of agriculture and erosion, to the complex ways watersheds are inter-connected. They also serve as teachers and mentors.

Collecting data nearby was Adam Heathcote, the Research Station’s director. “We’re training the next generation of water scientists out here,” he says.

Working side-by-side with early career colleagues provides senior scientists with skilled assistance and fresh ideas, while offering staff at the start of their careers lots of real-world experience and supportive relationships.


When people say they use a broad range of skills at the Research Station, they don’t just mean collecting samples or analyzing data. Research methods also include paddling and portaging or snowshoeing and skiing to remote study sites. Lienne Sethna does it all, and says it’s what makes working at the research station special.

Like many scientists, Lienne loved being outside as a kid, always exploring nature. Now, she gets to keep doing that in her work.

Every summer for the past three years, she has traveled around northern Minnesota, leading a significant study of the state’s wildest lakes. Several sites are in the Boundary Waters Canoe Area Wilderness, where the lakes are undeveloped, motorboats aren’t allowed, and the only way to travel is a canoe. Other study lakes are deep in the Superior National Forest, accessed by long gravel roads.

Venturing into such places has helped expand knowledge of lakes that were thought to be largely unaffected by humans, and how and why they change.

“We found that some of these shallow lakes do in fact thermally stratify,” Lienne says. “We didn’t think so, but now know that stratification could be enabling anoxia, or low oxygen content, in the water. And that can cause algae blooms.”

One summer day, at the end of a portage trail in the Boundary Waters, Lienne set down the canoe she had just carried between two lakes. It was time for a snack and water break before setting off to the next study site.

The lake was covered in a layer of thick green goop, a possibly toxic form of algae. It was why Lienne and her coworkers were there. By closely observing and studying the history of such lakes, they can better understand why some break out in algae blooms like this, and others do not. In a future where climate change, development, industrial agriculture, and other forces are at work, protecting lakes means knowing how they function as interconnected systems of water and life.

And it lets Lienne keep playing outside, using both backcountry and research skills, contributing to critical environmental science.


Once the rocks had been scrubbed, the North Shore crew moved on to their next tasks in a carefully coordinated routine. They measured stream flow and tree canopy cover, collected water and algae, deployed sensors, fought black flies and mosquitoes. They did this every month in a dozen rivers and lakeshore sites all summer.

By collecting all this information, what is likely the largest set of data about North Shore rivers ever created, Research Station scientists are building a complex understanding of these cherished waters.

Mari Leland, working closely with senior scientist Dr. Mark Edlund, both wearing waders and bent over their instrument, says the work has shaped her future plans. “Field work is a blast,” she says. “And it makes it much easier to understand what you’re doing in the lab.”

After receiving her bachelor’s degree from Purdue University in 2022, Mari says she saw a lot of possible jobs that would offer either field or laboratory work, but the Research Station was one of the few opportunities that provided both. She was appointed as Environmental Fellow in 2023, and then promoted to a full-time technician. She is considering her next career steps, and the Research Station is the perfect place to do it.

“Right out of the gate, I was trusted with a lot,” she says. “But I got a lot of support, too.”

The collegial atmosphere has another benefit. Working with people at all stages of their career means mentorship is built into the job. Mari always knew she was interested in science, and particularly the study of DNA, but didn’t see herself in the medical field. She hadn’t known of the need for such skills in environmental sciences, which was in line with her interests and experiences. And she just didn’t understand the long and winding path of pursuing advanced degrees.

”I never thought I’d do a PhD, but now I’ve applied for programs,” she says. “Working here makes it much easier to imagine doctoral work.”


Hailey Sauer’s career has intersected the research station at several points. She received her PhD from the University of Minnesota last December and is now working at the station as an postdoctoral fellow. But this place and its people also helped get her an early start on her path toward science, while she was still an undergraduate student at the University of Wisconsin-River Falls.

That was when Hailey took Dr. Jill Coleman Wasik’s class. Coleman Wasik was on staff at the Research Station until 2013, when she started as a professor in River Falls. She has kept close ties to her former colleagues and brings a class out for hands-on experience most winters. Hailey was one student who ventured onto a frozen lake with Station scientists and helped extract sediment cores from the bottom. Having previously taught K-12 students, she was excited about the idea of doing research at an institution dedicated to education, but outside traditional academia.

Hailey got an internship at the Research Station, and never looked back. Support and advice from senior staff helped her decide to pursue a PhD.

“I never would have dreamt it without the people here,” Hailey says. “I was learning skills at the lab bench, but they were also challenging me to think about where I wanted to go next.”

When she started her doctoral work a couple years later, now-director of the Research Station, Dr. Adam Heathcote, was on her advisory committee.

Now, back at the Station, Hailey is working on research with important implications for lakes and rivers, including the Salty Lakes project. This research is studying the impacts of rising salt levels in Minnesota lakes, and she is helping understand the changes it is causing to aquatic food webs. Through her career so far, she has learned a lot from the Research Station, and is now bringing new knowledge of genetic research to the team.


After collecting samples from four or five sites in a day, the team typically retired to their hotel in Tofte. There, they would pump water samples through filters to capture the invisible nutrients, algae, and other material that affect the aquatic ecosystem.

The last morning of this trip, the crew headed back to Grand Marais, though not to collect samples or eat fish, but to work with a group of young children from the community. On a rocky beach next to the harbor, kids from the nearby YMCA summer program learned all about “rock snot” (a term they immediately loved).

Working with the nonprofit Minnesota Children’s Press, based in Grand Marais, the scientists were helping the children publish a book about their research over the summer. Mari and her colleagues helped them collect samples from the shallow water, and then look at them under microscopes. Seeing the otherwise invisible organisms and beginning to understand the complex ecosystem of Lake Superior inspired a lot of “whoas” from the kids.

As part of the Science Museum of Minnesota, the Research Station is ideal for people who want education to be part of their work. Sharing knowledge about lakes and rivers with a broad segment of Minnesotans is a natural and necessary part of every project.

“Science is only as useful as what you can communicate,” Mari says.

Traditional academia often prioritizes research and publication over teaching and communicating, while the Research Station staff see public engagement as a top priority — and integral to sound science.

“We need more scientists who want to teach,” says Hailey, who received a teaching degree and taught in K-12 schools before switching to the field of science.

The scientists have partnered with St. Paul Public Schools, participated in many hands-on events at the Science Museum, and collaborated with the Kitty Andersen Youth Science Center to help underserved youth find passion and careers in science.


When the kids headed back to the YMCA, the crew returned to the Research Station, ten miles north of Stillwater, Minnesota. There, they unloaded the van of its coolers full of water and mud and more. At this lab and field station in the forest along the St. Croix River, they can process and measure and compute, try to make sense of chemistry, biology, and why water works the way it does.

The lab is staffed by several more early career scientists, who are integral parts of every Research Station project.

“The full time lab staff is also amazing,” says Lienne. “It’s a team of really enthusiastic people who contribute a lot to the research.”

The laboratory, offices, meeting rooms, and library are all in a sprawling Japanese and Prairie School-influenced building by architect Mike McGuire. With lots of wood and windows in the design, the work inside seems to mingle with the natural world beyond. The Station’s property includes nearly 400 acres of prairie, forests, wetlands, and water.

For decades, the Research Station has been home base for scientists at every stage of their careers, doing interesting and important work. Immersed in the natural world both at the lab and in the field, the facility is a launching point for both research and careers. It’s also where a lot of adventures begin.

“You can’t complain when you go to work and canoe everyday,” Mari says. “Or get to stand in a North Shore stream.”


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One response to “Young scientists contribute to critical studies of lakes and rivers at St. Croix Watershed Research Station”

  1. Sarah Lilja Avatar
    Sarah Lilja

    Great article, Greg. It’s always interesting to hear about the SCWRS. Thank you!