Whether on one of Minnesota’s 10,000 lakes or elsewhere around the world, many anglers enjoy the peace that comes with casting a line out into the waters, waiting for a hungry, gill-clad swimmer to reveal its hidden life. While it’s not common to hear a fish before they bite, they hear us. The slap of a paddle against the water, the chatter of voices in conversation, or the hum of a boat’s motor can affect their actions and affect the catch of the day. Groundbreaking research at the University of St. Thomas sheds light on the matter.
“Any angler will tell you that fish are sensitive to sound, right?’ said Dr. Brooke Vetter, assistant professor of biology in the College of Arts and Sciences. “If you're out fishing and somebody goes cruising by in their boat, it's not a very polite thing to do.”
At St. Thomas, Vetter’s groundbreaking research looks at the impact of sound on fish, particularly the bluegill sunfish. While bluegills are not as impacted by noise as other species, they are helping Vetter and her team gain insights into what sounds drive different fish behaviors.
“We're particularly interested in my lab at looking at what frequencies or what sound pressure levels could cause hearing loss (in the fish), and what frequencies might disrupt reproductive behaviors,” she said.
With a doctorate focused on using sound to prevent invasive carp migration and postdoctoral research on fish hearing and physiology, Vetter continues the work through her faculty position in the Department of Biology at St. Thomas by exploring how human activities, such as motorboat noise, affect fish behavior and communication.
“They’re really supportive of us doing research, so I get to do a lot of research with students,” she said.
Amelia Berry ’26 is one of those students. She originally was matched with Vetter through the Ignite Scholars Program in the summer of 2023. A junior majoring in statistics and minoring in biology, Berry has since gained a Young Scholars Grant for independent research, with Vetter as a mentor.
“I've had the opportunity to develop both technical and analytical skills and gain confidence in presenting my research,” Berry said. “It’s also been great to collaborate with such a supportive mentor and to feel like I’m making a meaningful contribution to ongoing research.”
St. Thomas was recently included in a new research classification from the Carnegie Classification of Institutions of Higher Education as a Research College/University. The classification highlights St. Thomas' dedication to research and scholarship at the undergraduate and graduate levels.
Senior Alexandra Johnson is grateful for the opportunities she has had working with Vetter on two projects. The senior from Woodbury is majoring in biology with a minor in sustainability. She's been Vetter’s research assistant and had her own project. She investigated how boat motor noise affects two freshwater fish species.
“It pushed me to communicate scientific ideas clearly, both in writing and conversation,” she said about her experience. “Most importantly, it made me more curious and compassionate as a scholar – reminding me that even small, often overlooked organisms are affected by the world we build around them.”
Johnson will travel with Vetter to Prague to attend the 2025 Conference on the Effects of Noise on Aquatic Life. The summer conference brings together people interested in the effects of sound on aquatic life from diverse national and academic backgrounds. They will share information and ideas, and the book will be published based on the research discussed at the convention. Johnson will have her paper published in the book.
"I'm beyond excited for my research trip to Prague this summer. It will be so cool to present at not only new conferences but also in a new country with people from all over the world," said Johnson.
"I cannot wait to be emerged into new culture and see all unique architecture in Prague as well. This will be an unforgettable experience and trip of a lifetime. I'm so grateful for the opportunity!"
Vetter brought a student to the same conference in 2022, which was held at that time in Berlin, as well as other students to other conferences.
“It's been really fulfilling to be able to give students those experiences,” Vetter said.
During a pilot experiment for bluegill fish, she remembers feeling stressed, in part because she had to drive over an hour one way to and from St. Cloud. Fishing off the dock in St. Cloud was the best way to gather the bluegills. Amid stress about project deadlines and practical matters, Vetter found beauty.
“I realized, as I was sitting on the dock, fishing and, listening to the radio. It was just this really calm, peaceful morning,” Vetter said.
The experience became a reminder for her to enjoy the journey. That pilot study went so well, developing into a full study – the very one they will present in Prague.
“That was a good memory,” Vetter said “Everything works out in the end.”
