Methods for the collection and analysis of benthic macroinvertebrate assemblages in wadeable streams of the Pacific Northwest

About this Document

The sampling protocols described in this document were designed to generate data sufficient to characterize the benthic macroinvertebrate assemblage and evaluate impacts from human caused disturbances. The purpose of this protocol is to characterize the macroinvertebrate assemblage for a stream reach as an indicator of biological integrity and stream health. It is not intended to characterize the condition of individual stream habitats or to provide data to analyze the macroinvertebrates as a food source for fish.
This protocol describes field, laboratory and data analysis methods for benthic macroinvertebrates. It is highly recommended that other physical habitat, biological and/or water quality data also be collected at any given site. PNAMP continues to strive to produce recommendations regarding protocols for these types of data in the near future.
We recognize that integrating existing methods requires significant work by program staff and we would like to acknowledge the contribution of many experts to create this product. The concept for a standardized protocol on this topic emerged from the Northwest Biological Assessment Workgroup (NBAW) and the members of NBAW were primary contributors and reviewers of this product. This protocol was synthesized from the following protocols:

• Oregon Department of Environmental Quality
• Washington Department of Ecology (Ecology, 2001)
• Multi-federal agency sponsored monitoring program (U.S.F.S., 2004)
• U.S. Environmental Protection Agency (EPA)'s Environmental Monitoring and Assessment Program (Peck et al., 2006)
• Bureau of Land Management (BLM)'s National Aquatic Monitoring Center (Hawkins et al., 2001)

These collection procedures, along with other environmental data, will allow analysis of biotic data with either multi-metric [e.g., an Index of Biotic Integrity (IBI)] or predictive models [e.g., River InVertebrate Prediction and Classification System (RIVPACS)] methods. Use of these procedures will allow users to share data, express their data in terms of standardized bioassessment measures, and thus directly compare their results with all other parties using these methods. Their general use does not preclude use of other sampling procedures that may be needed to address the specific objectives of individual projects.