CHARACTERIZATION OF VARYING LOCAL WINTER STREAM HABITAT AND ITS IMPACT ON COLDWATER FISHES

Stream dwelling fish in temperate latitudes are subject to widely varying in-stream winter conditions. Understanding the relative importance of the different factors that contribute to these winter conditions is important in predicting how environmental shifts will affect fish communities. In this study, I examined stream sections within 13 streams located in Marquette and Alger Counties within the Upper Peninsula of Michigan. Streams within a small geographical area were chosen to minimize latitudinal climate variation. Many in-stream winter conditions are driven by temperature so the importance of understanding how changing localized climate patterns may affect the structure and condition of fish communities is of paramount importance to predicting the local impacts of global climate change. During the winters of 2011-12 and 2012-13 winter conditions including temperature, ice conditions, and substrate movement were observed. I used K-means cluster analysis to combine scaled data into three stream classifications based upon temperature-driven winter characteristics (Air Driven, Winter Dynamic, and Thermally Stabilized). Using our classifications, I compared stream class against biological components of each study reach collected from fish captured via electroshocking. While there were no statistically significant differences between clusters for species richness, diversity, or change in condition (∆K), there were trends toward Winter Dynamic stream reaches having lower values