Ecosystem Science Reports

Aquatic Sciences

Project Title: Benthic Invertebrate Assessment of Streams in the Georgia Basin Using the Reference Condition Approach: Expansion of the Fraser River Invertebrate Monitoring Program 1998-2002.

Completion Date: March 2005

Investigators: S. Sylvestre, M. Fluegel and T. Tuominen, Aquatic and Atmospheric Sciences Division, Environment Canada, Pacific and Yukon Region

Study Overview

Benthic invertebrates provide an environmental warning signal regarding the health of streams. They are important components of stream environments because they are a food source for most fish; they are sedentary; they are intimately linked with bottom sediments; and they respond to a variety of stressors with various sensitivities. Invertebrate communities can be easily monitored, acting as indicators of cumulative exposure to chemical and physical stressors over a period of time.

Intensive urban development and agricultural activity in the Georgia Basin are a concern with regard to their effect on stream quality. Benthic macroinvertebrates were used to assess the current biological quality of streams in the Georgia Basin . The assessment approach was based on a biomonitoring program developed for the Fraser River Basin which used the Reference Condition Approach and the BEAST (BEnthic Assessment of SedimenT) assessment method.

The reference condition database developed for the Fraser River Basin was expanded to include 55 streams in the Georgia Basin . As a result, the Fraser River assessment model was modified and the new Fraser/Georgia Basin model was used to assess 46 streams exposed to urban and agricultural activities. BEAST assessments were accompanied by other commonly used bioassessment tools such as observed to expected taxa ratios and bioassessment metrics, which are often part of a benthic index of biological integrity. Together, these tools provided a clear description of the benthic invertebrate community and its similarity or dissimilarity to an appropriate reference condition.

Key Points for Decision-Makers

Key Scientific Findings

Key Points for Decision-Makers

• Ninety per cent of the streams sampled in urban and agricultural areas indicated some level of possible impairment. Two thirds of the streams indicated significant impairment and detailed water quality studies should be conducted to identify probable stressors.
• Biological monitoring could be used to as an early warning signal indicating where water quality problems may be occurring. Together, water quality and biological monitoring can track the cumulative effects of anthropogenic activities on stream quality. Biological monitoring may pick up ecological signals that may be missed by the suite of water quality variables that are routinely monitored. The relatively small additional cost of biological monitoring provides significant value to a water quality monitoring program.
• This approach should be promoted as a basis for the development of biological guidelines and standards by agencies such as CCME and Environment Canada for assessing impacts of human activities on aquatic ecosystems in addition to current chemically based environmental quality guidelines. Correlation of biological information with the CCME Water Quality Index will provide a more complete assessment of ecological condition of freshwater systems.
• With the development of the Canadian Aquatic Biomonitoring Network (CABIN) website (http://cabin.cciw.ca/cabin/) and online nationally consistent resources (database, software, Fraser River/Georgia Basin models, standardized protocols, and field sheets), biological monitoring is made convenient and easy in the Fraser River Basin and Georgia Basin and should be easily incorporated into biomonitoring and assessment programs. CABIN protocols are consistent with those highlighted on the national Environment Monitoring and Assessment Network (EMAN) website for measuring biodiversity of benthic macroinvertebrates in lotic freshwater systems (http://www.eman-rese.ca/eman/ecotools/protocols/freshwater/benthics/intro.html). It would be advantageous for municipalities to work with watershed stewardship groups to monitor the streams in their communities and report to local government when impaired or declining conditions are detected.

Key Scientific Findings

• Ninety per cent of the streams sampled in urban and agricultural areas indicated some level of possible impairment. Two thirds of the test sites fell outside of the 99% confidence ellipse indicating that they were stressed or severely stressed.
• The addition of 25% more reference sites from the Georgia Basin did not significantly change the predictor variables in the Fraser River assessment model or the error rate of the model.
• Test sites should be assessed individually unless spatial or temporal variation is the objective of the assessment.
• The value of collecting replicates at test sites should be investigated for a precise assessment of stream quality.

References

The data is archived in a web-accessible CABIN (Canadian Aquatic Biomonitoring Network) database maintained by NWRI (National Water Research Institute). The report is an Environment Canada GBAP report and an expansion of Environment Canada’s FRAP report: D.M. Rosenberg, T.B. Reynoldson, and V.H. Resh, 1999 Establishing reference conditions for benthic invertebrate monitoring in the Fraser River catchment, British Columbia, Canada . DOE FRAP 1998-32.

An abstract of this report is published on Environment Canada's Green Lane web site in both official languages. It is available at:

English - http://www.pyr.ec.gc.ca/georgiabasin/reports/BenthicInvertebrateAssessment/ECGB0481_e.htm

Français - http://www.pyr.ec.gc.ca/georgiabasin/reports/BenthicInvertebrateAssessment/ECGB0481_f.htm

A copy of the report may also be obtained directly from the author at:

Stephanie Sylvestre
Environment Canada, Environmental Conservation Branch
#201 - 401 Burrard Street, Vancouver BC, V6C 3S5
604-664-4099
stephanie.sylvestre@ec.gc.ca

The correct citation of the paper is:

Sylvestre, S., M. Fluegel and T. Tuominen. 2005. Benthic Invertebrate Assessment of Streams in the Georgia Basin Using the Reference Condition Approach: Expansion of the Fraser River Invertebrate Monitoring Program 1998-2002. Environment Canada, Georgia Basin Ecosystem Initiative, Report EC/GB/04/81.