Biological Monitoring

Data in some cases is preliminary pending final checks.

About the B-IBI

To make a broad assessment of ecosystem health in our streams, Streamkeepers uses the Benthic Index of Biological Integrity (B-IBI), a stream-health grading system based on aquatic invertebrates found at monitoring sites, developed and calibrated at the University of Washington and further calibrated by a consortium of Puget Sound local governments.

Use of the B-IBI for Water-Quality Assessments in WA State Under the Clean Water Act

Prior to 2004, biological assessments were not used in Washington State for further investigation of pollutant sources under the federal Clean Water Act. In 2004, Streamkeepers was able to establish a new precedent, requiring that the Washington State Department of Ecology (DOE) perform further assessment of stream segments where biological impairment has been found. DOE's 2006 revised Water Quality Program Policy reflected a new approach to the use of biological assessment, which has continued to evolve in subsequent years.