Brook Trout Status and Distribution in the Lake Superior Basin

Brook trout are the only stream dwelling trout native to the upper Midwest and populations have declined dramatically since early settlement.  However, the extent,  severity, and in some cases, the specific cause of the decline is unknown.  Current fishery data along with landscape scale GIS data are being used to model the status and distribution of brook trout at the NHD catchment and subwatershed scales in an effort to complete a range-wide status and distribution map throughout their native range in the United States.  Contributing toward this goal, brook trout status in the Lake Superior Basin was determined in a method compatible with the Eastern Brook Trout Joint Venture in order to create a single unit of measure across their range.  Catchments and subwatersheds with sufficient data were classified according to brook trout population status, and a random forest model has been developed to identify threats to brook trout populations and predict brook trout status in areas where fishery data are insufficient.  The end product, geo-referenced maps and data will assist biologists, land managers, and other interested parties evaluate and prioritize areas for protection, enhancement, or restoration of brook trout populations and provide a baseline for monitoring brook trout populations into the future.