Walleye (Sander vitreus), Yellow Perch (Perca flavescens) and Surface Water Mercury Concentrations in Minnesota Lakes

Water quality and fish tissue samples were collected and measured for mercury concentrations in a total of 23 small to medium size lakes in Minnesota to assess the impact that zebra mussel (Dreissena polymorpha) invasion had on mercury bioaccumulation. Water samples were collected in October and November of 2021 from 22 lakes and analyzed for total mercury, methylmercury, dissolved organic carbon, and suspended particulate matter at the U.S. Geological Survey (USGS) Mercury Research Laboratory (MRL). Tissue samples of walleye (Sander vitreus) and yellow perch (Perca flavescens) were collected by researchers at the University of Minnesota, Twin Cities from July to October in 2019 and 2021 and June to October in 2020 and 2021. Assessment of trophic patterns and energy pathways were performed by the University of Minnesota and a subset of samples were analyzed for total mercury by the USGS MRL.