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General introduction

King County's Benthic Index of Biotic Integrity (B-IBI) is composed of ten metrics that measure different aspects of stream biology, including taxonomic richness and composition, tolerance and intolerance, habit, reproductive strategy, feeding ecology, and population structure. Each metric describes some aspect of the community that responds to degradation. The raw value of each metric is calculated, and from the raw value, a score of 1, 3, or 5 is assigned to the metric. The ten metric scores are then added to produce the overall B-IBI score that range from 10 to 50.

Also, the Puget Sound stream benthos website was developed by a group of agencies interested in monitoring the health of streams in the Pacific Northwest. The City of Seattle, King County, Pierce County, and Snohomish County worked collaboratively to create a database system that allows sharing of benthic macroinvertebrate data among many organizations and provides tools for calculating metrics and indices. The site is used to store and analyze data from ongoing macroinvertebrate sampling programs.

Monitoring reports

B-IBI scores for streams around King County from 1994 through 2001 (Microsoft Word format)

Sampling and Analysis Plan (SAP) for new macroinvertebrate studies: Greater Lake Washington and Green-Duwamish River Watersheds Wadeable Freshwater Streams Benthic Macroinvertebrate Sampling and Analysis Plan.

2002 Report: Benthic Macroinvertebrate Study of the Greater Lake Washington and Green-Duwamish River Watersheds Year 2002 Data Analysis and 2002 Appendices.

2003 Report: Benthic Macroinvertebrate Study of the Greater Lake Washington and Green-Duwamish River Watersheds Year 2003 Data Analysis, including apendices.

For questions about information on this page, please contact Deborah Lester, Risk Assessment Lead, or Jo Wilhelm, Environmental Scientist.