Cooperative Fish and Wildlife Research Units Program: Minnesota
Education, Research and Technical Assistance for Managing Our Natural Resources

Asmus, B., J. Magner, B. Vondracek, and J. Perry. Physical integrity: the missing link in biological monitoring and TMDLs. (Accepted by Environmental Monitoring and Assessment, posted in Online First)


The Clean Water Act mandates that the chemical, physical, and biological integrity of our nation’s waters be maintained and restored. Physical integrity has often been defined as physical habitat integrity and as such, data collected during biological monitoring programs focus primarily on habitat quality; however, we argue that channel stability is a more appropriate measure of physical integrity. We highlight assessment tools that could supplement stream assessments and the Total Maximum Daily Load stressor identification process: field surveys of bankfull cross-sections; longitudinal thalweg profiles; particle size distribution; and regionally calibrated, visual, stream stability assessments. Benefits of measuring channel stability include a more informed selection of reference or best attainable stream condition for an Index of Biotic Integrity, establishment of a baseline for monitoring changes in present and future condition, and indication of channel stability for investigations of chemical and biological impairments associated with sediment discontinuity and loss of habitat quality.