Long-Term Monitoring of Southeast Minnesota's Driftless Area Streams: Evaluation of New Environmental Threats and Management Responses

Historical landscape changes from forest and prairie to urbanization and agriculture severely impacted streams by increasing sediment, nutrient loads, and stream temperatures, and altering stream morphology and hydrology. Soil conservation activities and stream management during 1950s-1980s improved streams, but changing climate, future land use practices, and aquatic invasive species are predicted to alter thermal and hydrological cycles, re-stressing aquatic communities. Our goal was to initiate and maintain a long-term monitoring (LTM) program with emphasis on the MN Driftless Area that integrates five stream components: hydrology, geomorphology/fish habitat, biology, water quality, and connectivity. There are 23 LTM stations in SEMN sampled annually. Project goals are to specifically determine how temporal changes in land-use practices, climate change, and invasive species affect the five stream components, which in turn determine sustainability of associated fisheries resources and angler satisfaction. Extensive trout population data shows variability in recruitment and size of age-0 trout across years and streams. Recent severe flooding has impacted trout recruitment but not all the variation is explained. Temperature patterns appear to be changing most during September, March and April, which could influence spawning phenology and spring fry emergence. Monitoring will continue to provide high-quality, comprehensive baseline data for various evaluations.