A Geographical Classification of Minnesota Fishing Lakes

Fish communities in Minnesota lakes vary significantly across the state along a gradient corresponding with spatially correlated habitat factors including lake morphology, nutrients, alkalinity, land cover, precipitation, temperature, and various other climatic and geomorphic variables.  Regionalization schemes (ecoregions) and GIS data sets that spatially attribute key habitat factors have improved the analytic capacity for describing the geographic influences on fish communities in lakes.  Aided by this information, we used a hierarchical decision tree procedure to classify lakes based on correspondence between fish communities and geographical habitat features.  The resulting statewide classification contains seven classes of lakes with relatively uniform habitat influences on fish community composition established by EPA level IV ecoregions, transparency (Secchi), and lake surface area.  These variables are readily recognized by aquatic science professionals as well as the public which should enhance future efforts to communicate and implement place-based fisheries research and management strategies.