Assessing trends—and eventually improvements—in freshwater quality and stream condition using the Benthic Index of Biotic Integrity (BIBI)

Presentation Abstract

The Puget lowlands Benthic Index of Biotic Integrity – the BIBI – has been used since the 1990s to assess freshwater quality and condition in streams throughout the Puget Sound basin. Among indicators, the BIBI is a rather robust and non-diagnostic measure of stream conditions. BIBI scores reflect the integrated and cumulative effects of multiple stressors associated with land conversion and development on stream macroinvertebrate community composition. Using King County’s long-term BIBI data from 126 sites, we will present the current status and trends in BIBI scores. BIBI scores at nearly 85% of sites are not significantly improving or declining, despite an increase in urbanization over the sampling period. Discussion will include how sensitive trends in BIBI scores are to land use change and stormwater best management practices within their contributing basins, and what that may mean for detecting trends following mitigation or restoration efforts. Although not perfect, the BIBI has been recognized as the best available biological measure for freshwater quality by agencies working to restore and protect Puget Sound. With that designation comes the unproven expectation that the BIBI will be responsive to restoration actions. Trends analysis across ambient monitoring sites should help inform our restoration plans and our expectations for measuring improvements.

Session Title

Biological Indicators of Stormwater Impacts and Mitigation Effectiveness in the Salish Sea

Conference Track

SSE3: Fate, Transport, and Toxicity of Chemicals

Conference Name

Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)

Document Type

Event

SSEC Identifier

SSE3-512

Start Date

6-4-2018 9:30 AM

End Date

6-4-2018 9:45 AM

Type of Presentation

Oral

Genre/Form

conference proceedings; presentations (communicative events)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Subjects – Topical (LCSH)

Stream health--Washington (State)--Puget Sound Watershed; Water quality--Washington (State)--Puget Sound Watershed--Testing

Geographic Coverage

Puget Sound Watershed (Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

Text

Language

English

Format

application/pdf

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Apr 6th, 9:30 AM Apr 6th, 9:45 AM

Assessing trends—and eventually improvements—in freshwater quality and stream condition using the Benthic Index of Biotic Integrity (BIBI)

The Puget lowlands Benthic Index of Biotic Integrity – the BIBI – has been used since the 1990s to assess freshwater quality and condition in streams throughout the Puget Sound basin. Among indicators, the BIBI is a rather robust and non-diagnostic measure of stream conditions. BIBI scores reflect the integrated and cumulative effects of multiple stressors associated with land conversion and development on stream macroinvertebrate community composition. Using King County’s long-term BIBI data from 126 sites, we will present the current status and trends in BIBI scores. BIBI scores at nearly 85% of sites are not significantly improving or declining, despite an increase in urbanization over the sampling period. Discussion will include how sensitive trends in BIBI scores are to land use change and stormwater best management practices within their contributing basins, and what that may mean for detecting trends following mitigation or restoration efforts. Although not perfect, the BIBI has been recognized as the best available biological measure for freshwater quality by agencies working to restore and protect Puget Sound. With that designation comes the unproven expectation that the BIBI will be responsive to restoration actions. Trends analysis across ambient monitoring sites should help inform our restoration plans and our expectations for measuring improvements.