Brook Trout Relative Abundance Modeling in Lake Superior Tributaries Based on Habitat Characteristics: Impacts of An Exotic Salmonid Removal

Native brook trout (Salvelinus fontinalis), coho salmon (Onchorhynchus kisutch) and steelhead (O. mykiss) within Michigan’s Pictured Rocks National Lakeshore have been the focus of a project designed to evaluate the impacts of non-native salmonids on brook trout relative abundance and spatial distribution.  The Exotic Salmonid Removal (ESR) project has produced several years worth of fish population and habitat data that provides a detailed view of three rivers within the park (Sevenmile Creek, Mosquito River and Hurricane River).  We developed a Geographic Information Systems database using georeferenced in-stream standard stations.  This spatial data was combined with our suite of habitat variables (physical, chemical and biological) and fish population data sets to analyze the spatiotemporal distribution of brook trout.  In addition, the resulting database was modeled within HyperNiche to explore the effect of changing exotic salmonid density on brook trout relative abundance.  This model was validated by statistically comparing predicted values to populations observed during the field work of summer 2011.