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Specific macroinvertebrate monitoring projects

Learn about special King County projects involving macroinvertebrates, also known as stream bugs.

King County Ambient Monitoring Program Methods

The King County Freshwater Benthic Macroinvertebrate Sampling and Analysis Plan for annual monitoring. These are the protocols we follow at each sampling site.

Regional Puget Sound B-IBI Projects

King County has worked with partners in the region on projects related to stream health and B-IBI. B-IBI stands for the Puget Lowland Benthic Index of Biotic Integrity. WA Department of Ecology and EPA’s National Estuary Program funded most of these studies. Links to more information about the projects are in the sections below.

20-year trends monitoring

King County’s Water and Land Resources Division has been collecting freshwater macroinvertebrates, or “stream bugs,” in streams throughout the County since 2002. The objective of the Ambient Freshwater Benthic Macroinvertebrate Monitoring Program is to track stream biotic integrity, or a stream’s ability to support naturally diverse macroinvertebrate communities native to the region. In this study, we used our long-term monitoring data to examine how the biotic integrity of 120 King County stream sites has changed over a twenty-year period. In addition, we conducted an exploratory analysis of environmental and methodological variables that have changed over time in an attempt to identify potential drivers of the changes we observed. We present our findings in this report, and lessons learned from the effort for resource managers and multi-metric index practitioners.

Project documents

Impact of Urban Development on Stream Macroinvertebrate Communities is Influenced by when Development Occurred

King County staff investigated if and how the timing of development in a stream basin helps explain the variation in stream macroinvertebrate communities and measures of stream health. We found that basins with the newer development had better B-IBI scores than basins with older development. This suggests actions that have been implemented to minimize effects of urban development have had some positive effects. The study results indicate that urban development is still the leading cause of degraded conditions, but the relative impact of newer development appears to be less than previous development.

Project documents:

Impact of Forest Condition on Macroinvertebrate Communities and Biotic Integrity

King County staff investigated if and how forest conditions affect stream health. We used B-IBI scores as our measure of stream health. Our goal was to see if forest harvests impact B-IBI scores in forested basins. But it is difficult to get accurate measures of past forest harvest. Instead, this study focused on forest conditions influenced by forest harvest. We looked at different potential mechanisms and spatial scales of impact.

The results suggest that disturbed forest conditions have little influence on B-IBI scores. The influence we observed decreased as distance from the stream increased. These results apply to forested watersheds with very little residential or commercial development.

Project documents:

The Restore and Protect Project

The Puget Sound Partnership has specific recovery and protection targets for B-IBI.  King County has completed two projects related these targets.

– Phase I -. The first project focused on developing a framework for restoration and protection targets. This framework helps to identify and rank stream basins for restoration or protection. The framework uses B-IBI scores as part of the process. 

– Phase II –. The second project focused on developing basin-specific restoration and protection plans. This study made recommendations for 14 Puget Sound basins. The general approach can apply to streams across the Puget Sound region.

The Bug Seeding Project

This project aimed to jump-start the recovery of several degraded King County streams. These streams had poor B-IBI scores compared to their water and habitat quality. This project seeded these streams with macroinvertebrates (“stream bugs”) collected from healthy streams.

The Recalibration of the Puget Lowlands B-IBI

King County worked with regional partners to standardize and update the B-IBI process. This work lasted from 2010-2014. This effort improved the tools that track benthic macroinvertebrate in the Puget Lowlands. This included updating and recalibrating the B-IBI scoring system, and comparing field methods. The effort also evaluated how environmental stressors affect macroinvertebrate communities.

Historic monitoring reports

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

Sampling and Analysis Plan (SAP) for 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 appendices.