Meet Our Dedicated Team!
Dr. Gretchen JA Hansen
Dr. Hansen is an associate professor of Fisheries Ecology in the Fisheries, Wildlife, and Conservation Biology department at the University of Minnesota. Prior to joining the FWCB faculty in 2018, Dr. Hansen worked for five years as a research scientist for the Departments of Natural Resources in Minnesota and Wisconsin.
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2003 Upper Buford Cir; 135 Skok Hall;
Saint Paul, MN 55108
Fish, Wildlife, and Conservation Biology Department
University of Minnesota - Twin Cities
Research Staff
Denver Link, MS
Denver is a researcher who addresses threats to freshwater ecological systems using field and quantitative skills. He earned a MS degree in the Hansen Lab studying zebra mussel impacts on aquatic food webs and fish mercury concentrations. Graduating from St. Olaf College in 2021 with degrees in biology and environmental studies, he enjoys understanding anthropogenic changes in aquatic environments. During his undergraduate studies, Denver spent two summers with the Iowa Department of Natural Resources Fisheries Bureau studying fish populations on the Upper Mississippi River. As a native of Dubuque, Iowa, he appreciates the distinctiveness of the Driftless Area and finds great interest in the intricate interplay among policy, science, and management involved in safeguarding it from land use changes. Outside of the lab, Denver enjoys fishing, supporting the Denver Broncos, and coaching alpine ski racing.
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Naomi Blinick, MS
Naomi Blinick is a researcher in multiple labs in the Fisheries, Wildlife, and Conservation Biology department at the University of Minnesota, with over 15 years of experience as a field biologist specializing in aquatic ecosystems. She holds a master’s degree in Conservation Sciences from the University of Minnesota, where her research in the Hansen Lab focused on the impacts of invasive zebra mussels on food webs and mercury concentrations in Minnesota walleye lakes. Naomi completed her undergraduate studies in environmental and marine studies at Prescott College in Arizona, giving her a strong interdisciplinary foundation.
Her current work with the Hansen Lab continues to focus on zebra mussels and fish mercury, as well as supporting projects related to coldwater fish habitat and paleolimnology. In other UMN labs, she supports research on aquatic revegetation post-treatment for aquatic invasive plants.
Naomi is also an experienced scientific diver and photographer, and in her free time enjoys knitting, reading, and spending time outside with her dog, Burch.
Postdoctoral Researchers
Dr. Ken Zillig
Ken is a conservation ecophysiologist who uses organismal physiology to understand the effects of environmental change on species and ecosystems. He completed his Ph.D. at the Unversity of California, Davis with Dr. Nann Fangue where his dissertation focused on interpopulation variation in the thermal performance and metabolism of juvenile Chinook salmon [1][2]. His past postdoctoral research focuses on the effects of nutrition on the thermal performance of young salmonids in the California Central Valley. Ken’s work in the Hansen lab will focus on quantifying the oxythermal physiology of Laurentian Coregonids and then integrating that physiological data with population models to understand how rapid environmental change may impact Great Lake populations.
Ken has additionally worked on the effects of food availability on green sturgeon metabolism, the impact of hydropower turbines on white sturgeon passage, the role of physiological performance on trophic interactions [3], the influence of ocean acidification and ocean warming on Antarctic rockcod and the development of swimming respirometers for tropical reef sharks.
His research interests focus on scaling organismal physiology to understand the influence of environmental change on species of commercial and conservation concern. Additionally, he has a passion for the development of novel physiological methodologies that expand our understanding of how fish interact with their environment. Ken is always eager for collaborations or just to chat about fish research and conservation.
Outside of the lab, Ken is an avid birder and a novice, but enthusiastic, woodworker.
Dr. Christopher J Sullivan
Chris is fascinated by actionable fisheries science and ecosystem ecology. Broadly speaking, Chris tries to combine spatial and temporal approaches to understand complex biological and ecological interactions associated with aquatic ecosystems. Chris has published manuscripts focusing on climate change impacts on riverine fish populations, invasion ecology of aquatic species, and critiques of field methods for fishery data collection. Chris attempts to pursue these topics using an adaptive research approach employing field sampling methods, statistical analyses, and simulation modeling, and builds research teams across traditional disciplinary boundaries.
Chris’s work in the Hansen lab will focus on landscape-scale patterns in lake thermal regimes and fish population abundance/growth.
Dr. Cam Mosley
Cam is a fisheries ecologist who is broadly interested in how fish communities respond to human impacts and environmental changes that alter fish habitat availability, sport fish populations, and fish behavior. They completed their Ph.D. at the University of Notre Dame with Dr. Stuart Jones performing several whole lake experiments to examine how recreational fish populations respond to habitat additions[1] and increases in angler effort in northern temperate lakes [2], in addition to a statewide analysis quantifying non-linearity of catch rates for six sport fish in Wisconsin[3].
In the Hansen lab, Cam will be collaborating with Hansen lab members on investigating differences in fish population structure across Midwest fisheries and on an National Science Foundation funded postdoctoral research fellowship in Biology with the aims of examining niche overlap between fish species across thermal guilds, climate-driven species distribution models, and collaborating with the Bell Museum to share their findings with the local community (Award #2410099).
In their free time Cam enjoys a plethora of outdoor activities including but not limited to fishing, camping, hiking, and taking naps on boats. They also enjoy trying new restaurants and walks with their cat Flounder.
Graduate Students
Christopher Rounds - MS (2023), PhD
Christopher is a Hansen lab PhD student in the Conservation Sciences program. He also completed his MS in the Hansen lab. During his MS he studied the optimization of eDNA sampling to detect four priority invasive species in Minnesota lakes. His PhD research focuses on identifying and understanding Midwestern United States fishery bright spots. In his free time, Christopher enjoys playing soccer and recreating on lakes.
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Michael McGuigan - PhD
Mike is a PhD student in the Hansen Lab who is generally interested in the effects of global change and anthropogenic stressors on aquatic ecosystems and identifying management strategies for their conservation. He graduated from Cornell University with a B.S. in Environment and Sustainability with a concentration in Environmental Biology and Applied Ecology, where he studied the role of zebra and quagga mussels in the phosphorus budget of Oneida Lake, NY with Dr. Lars Rudstam. Before returning to school for his PhD, Mike worked as a lab and field technician first at the University of Notre Dame in Dr. Stuart Jones’ lab, and later at the University of Michigan in Dr. Jacob Allgeier’s lab. His research in the Hansen Lab examines how extreme precipitation events, warming temperatures, and land use change affect coldwater fish habitat throughout Minnesota. In his free time, Mike enjoys running and spending time outdoors.
Amanda Schuermann - MS (2025), PhD
Amanda is a PhD student and MAISRC Scholar in the Hansen and Phelps labs with a passion for aquatic invertebrate zoology and invasive species ecology. She graduated from Truman State University in Kirksville, MO in 2023 with a B.S. in Biology, then received her M.S. in Biology from Bemidji State University in Bemidji, MN in 2025. There she studied how zebra mussels impact the population dynamics of benthic macroinvertebrates in the Mississippi River headwaters with Dr. Debbie Guelda. Her research now focuses on how aquatic invasive species (zebra mussels, mystery snails) impact the presence of swimmers itch in northern Minnesota lakes. When she isn’t in the lab, Amanda enjoys drawing, doing various crafts, baking, and getting outside!
Olivia Nyffeler - MS
Olivia is a Master’s student in the Hansen and Waterhouse labs studying drivers of Cisco (Coregonus artedi) Recruitment in Lake Superior. Her project is compiling historical and contemporary datasets from state, tribal and federal agencies working on Lake Superior. She graduated from the University of Wisconsin Madison in 2021 with a degree in Conservation Biology, Psychology, and a certificate in Environmental Studies. During her time there, she worked for the Center for Limnology on a whole lake maniuplation, removing bass and sunfish near Trout Lake Station. In her free time, Olivia enjoys walking her dogs Louie and Atlas, going on long bike rides, or reading good books.
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Grace Hemmelgarn - MS
Grace is a Master's student in the Hansen lab studying walleye population resilience to environmental stressors in Minnesota lakes over the last few hundred years, using zooplankton remains in lake sediments as indicators of historical fish communities. She graduated from Allegheny College in 2022 with a degree in Environmental Science & Sustainability and minors in Biology and Spanish, where she studied dispersal mechanisms of juvenile invasive Round Goby in a lotic system with Dr. Casey Bradshaw-Wilson. Grace has also worked on Lake Trout age estimation to update population parameters in Lake Champlain at the University of Vermont with Dr. Ellen Marsden. She studied environmental science and climate change in antarctic and sub-antarctic climates in Ushuaia, Argentina through the School for International Training where she investigated the diet of South American Sea Lions in the Beagle Channel. In her free time, Grace loves to ride horses, travel, and explore the outdoors.
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Mary Claire (MC) Fibbe - PhD
MC is a PhD student in the Hansen and Walsh Lab, where she studies how zooplankton can serve as bio-indicator species for lake health in Minnesota. She earned her B.S. in Marine Science with a concentration in Biology and a minor in Coastal Management from Eckerd College. During her undergraduate years, MC worked in the Eckerd College Microplastic Lab with Dr. Amy Suida, where she investigated the relationship between zooplankton and microplastic pollution. Between her time in Florida and Minnesota, she worked as a biological field station assistant at Ohio State University’s Stone Lab on Lake Erie and as a marine biologist with the Louisiana Department of Wildlife and Fisheries. When she’s not studying zooplankton, MC loves going on walks with her partner and dog, trying new foods, running, and enjoying the outdoors (especially near the water)!
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Undergraduate Technicians
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Jack Abel
Jack is a senior in the College of Biological Sciences majoring in Ecology, Evolution, and Behavior, and minoring in Marine Biology. He has worked for the Hansen lab as an undergraduate technician since the spring of his freshman year and has a deep passion for learning about aquatic ecosystems. In addition to assisting with various lab projects, Jack is currently in the final stages of completing his Honors Thesis research, where he is developing an updated lake classification system for Minnesota lakes primarily based on fish assemblage data. Working in the Hansen lab also led to him spending the past two summers as a field and laboratory assistant at UW-Madison’s Trout Lake Research Station on the Walleye Bright Spots project. Outside of fisheries research, he enjoys long-distance running, fly fishing, and exploring state parks.
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Evelyn Yang
Evelyn is a junior in CFANS majoring in Fisheries, Wildlife, and Conservation Biology with minors in Animal Science and Wildlife Care & Handling. She is an undergraduate technician in the Hansen lab working alongside Grace and Adele looking at zooplankton from lakes as part of walleye population research in the lab. In her free time, Evelyn enjoys being outdoors, working on jigsaw puzzles, or spending time with her dog and fish.
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Adele Jacobsen
Adele is an undergraduate double majoring in Environmental Science Policy and Management and Fisheries Wildlife and Conservation Biology. She is going into her junior year and is working with Grace on the walleye research. In her free time, Adele likes to do anything outside or with dogs.
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Maxwell Eagan
Max is a third-year student in the College of Biological Sciences, majoring in Ecology, Evolution, and Behavior with a minor in Marine Biology, and plans to graduate in the spring of 2026. He has been an undergraduate technician in the Hansen lab since the fall of 2024, working alongside Dr. Ken Zillig on the oxythermal physiology of Laurentian Coregonids project. He is also doing a UROP on the CTmax and morphometrics of Coregonids. Outside of the lab and research, Max enjoys SCUBA diving, spending time outdoors searching for animals, and attending college sports events, particularly Women's Soccer, Hockey, and Men’s Hockey.
Alumni
Dr. Michael Verhoeven
Role: Post-doctoral researcher
Jonah Bacon
Graduated: UMNTC - Spring 2021
Major: Ecology, Evolution, and Behavior
Minor: Marine Biology
Role: Field & lab technician
Mayra Velasquez - MS (2023)
Role: Master’s Student
Tristan Blechinger
Roles: Field & lab technician
Nikayla Barnes
Graduated - UMNTC Spring 2023
Major:
Minor:
Role: Field & lab technician
Amanda Van Pelt
Graduated: UMNTC - Spring 2022
Major: Ecology, Evolution, and Behavior
Minor: Environmental Science, Policy, and Management
Role: Field & lab technician
Leah Stern
Graduated: Macalester College - Spring 2021
Major: Biology
Role: Field & lab technician
Nicole Campagnola
Senior at Hopkins High School
Role: Step-Up Intern
Ashley LaRoque
Graduated: UMNTC - Spring 2021
Major: Ecology, Evolution, and Behavior
Minors: German and Marine Biology
Role: Field & lab technician
Claire Rude
Graduated: UMNTC - Spring 2020
Majors: Fisheries, Wildlife & Conservation Biology, and Environmental Sciences, Policy & Management
Role: Field & lab technician
