To track stream biological integrity based on sediment and nutrient loads, and temperature. Stream conditions affect its biological integrity, and fish are particularly impacted due to their sensitivity to environmental disturbances (flow regime, chemical and organic changes, thermal fluctuations, etc.). CWA 303(d) impaired stream listings are available in GIS format, and can be used to measure the proportion of total stream length per watershed. Also, NatureServe provides an ecological integrity assessment for wetland mitigation in some counties.