Fish data for Impacts of beaver dams on low-flow hydrology and hydraulics, Knife River, Minnesota

We conducted general fish surveys in 2018 around active beaver dams selected for low-flow hydrology and hydraulics in the Knife River (https://conservancy.umn.edu/handle/11299/220310), as a component of that project was to evaluate fish movement (preference on trout species) around beaver dams. However, we learned from the general fish surveys that the project locations were not optimal for testing fish passage of dams because few trout occupied those sections of the Knife River. In 2019 we selected beaver dams all less than 1 m in height in the Knife River and the French River which sustained populations of trout. Fish were collected using backpack electrofishing gear, fish >60 mm total length where marked with visible implant elastomer (VIE) and partial fin clips, and then we recaptured fish at a later date to determine how many moved past beaver dams or natural riffles which served as a control. Fish which passed control riffles indicate normal fish movement in streams during low-flow as a comparison to fish movement past beaver dams so we could determine if beaver dams <1 m in height are barriers to fish movement.