Implementing a Watershed Scale Framework to Protect Coldwater Lake Habitat in Minnesota

Coldwater lake habitat in Minnesota is expected to be reduced by climate warming with consequences for the long-term sustainability of native coldwater fish species like lake trout, cisco, and whitefish.  Despite this anticipated loss, simulations of future climate warming on water temperature and hypolimnetic oxygen predict that sustainable coldwater habitat will remain for a subset of lakes, providing thermal refuge habitat for coldwater species.  However, land disturbance activities in the watersheds of these refuge lakes can threaten hypolimnetic oxygen levels due to nutrient loading. The Minnesota Department of Natural Resources and local partners are collaborating to implement a comprehensive strategy to protect coldwater habitat by retaining forested land cover within watersheds of priority refuge lakes.  We applied modeling predictions of future summer hypolimnetic habitats and land use disturbance model predictions of nutrient loading to establish watershed disturbance thresholds and relative risk to coldwater habitat sustainability.  With targeted conservation, education and regulation delivered through our partners, resilience of coldwater lake habitats that sustain trout and coregonid species can be preserved for the benefit of Minnesota’s future generations.