Mississippi River-St. Cloud Watershed Stressor Identification Report

This report summarizes the key causes or "stressors", contributing to impairment of fish and aquatic macroinvertebrate communities of the Mississippi River tributaries in the Mississippi River-St. Cloud watershed located in central Minnesota. There are eight 11-digit HUCs that will be covered in this report that contain streams which are listed on the 303(d) list of impaired waters for failing to meet established criteria for the index of biological integrity (IBI). Stream biology is scored based on a numeric value given to each of several metrics which comprise the index. Metrics are based on community diversity, and reproductive, feeding, or trophic characteristics that are specific to groups of fish and macroinvertebrates. Low scores indicate a lack of certain groups of fish and invertebrates which mean that the stream is not meeting expectations. The elements of a healthy stream consist of five main components; stream connections, hydrology, stream channel assessment, water chemistry, and stream biology. The following chart shows the five components of a healthy stream. If one or more of the components are unbalanced, the stream ecosystem fails to function properly and the stream is listed as an impaired water body.