Watershed Council Macroinvertebrate Monitoring Program Development

Some Oregon Watershed Councils have been collecting macroinvertebrate data for five years or more, and new analysis models can provide additional interpretive and diagnostic information. However, to use these models, Watershed Council data must be manipulated into an appropriate format. Xerces staff are working with DEQ to translate data in the best way to fit the model, and are working with three Watershed Councils to fit their data into the models and interpret the outputs.

The Issue
Currently, more than a dozen Oregon Watershed Councils have monitoring databases that, combined, include watershed specific data from hundreds of macroinvertebrate monitoring sites. These Watershed Councils include the McKenzie, Nehalem, Rogue, South Coast, Mid-Coast, Umpqua, Yamhill, Upper Deschutes, Walla Walla, and several others. As valuable as such macroinvertebrate monitoring coverage is, none of the data is in a format that can be analyzed with the Oregon Department of Environmental Quality's (DEQ) recently completed, statewide River InVertebrate Prediction And Classification System (RIVPACS) analysis model for Oregon. Once formatted for the model, data can be used to identify potential stressors of biological integrity and to enhance the TMDL (Total Maximum Daily Load) process. This program will help watershed councils meet Oregon Plan monitoring goals to document existing conditions, track changes, and determine the impact of programs and actions.

The RIVPACS Model and TMDLs
DEQ's Water Quality Program's primary focus is the implementation of federally mandated, basin-specific TMDLs (Total Maximum Daily Load). This program has relied on traditional water-quality parameters such as temperature, pH, dissolved oxygen, and nutrients in the past. Recently, the products of DEQ's biological monitoring efforts have gained acceptance in the Water Quality Program as an important tool in the TMDL process. The biological data are used at the beginning of the process to determine if a waterbody is impaired and to identify specific stressors. During the TMDL process, biological data can be used to determine the effectiveness of the TMDL program by monitoring improvement in the water quality condition. The analysis tool DEQ developed to determine impairment is a statewide model based on the RIVPACS model developed in Great Britain in the mid-1980s.

The Oregon RIVPACS model uses several characteristics of the sample site (including latitude and longitude, gradient, and date sampled) to compare the site to a large database of reference or least-disturbed sites. Once the relationship of the sample site to reference conditions has been established, the model predicts an assemblage of macroinvertebrates that should be present at the site in the absence of impairment. The model then compares the assemblage that was actually collected to the prediction, producing a biological condition score and other output. Though the output is relatively easy to understand, the model requires uploaded data to be in a very specific format, different from that which has been produced by macroinvertebrate laboratories in the past.

In addition to the RIVPACS model, DEQ staff has developed a valuable stressor identification model that can diagnose whether temperature or sedimentation are likely stressors, based on the organisms collected at a site. Watershed Councils have expressed particular interest in using the stressor identification models in their monitoring programs.

Need for Formatted Watershed Council Data
With the recent completion of the DEQ macroinvertebrate model, the Xerces Society and DEQ have an opportunity to partner with watershed councils to analyze their data using the RIVPACS model. In this project we will work with three watershed councils that have expressed a need for this analysis. The Nehalem River Watershed Councils have several years of data that need to be interpreted using the model to satisfy obligations to the DEQ. The McKenzie River Watershed Council also has several years of data; they attempted to analyze some of their data using a draft model produced at Utah State University, but the analysis was never performed. In 2003, Walla Walla Basin Watershed Council and Xerces staff discussed future applications of their data but did not have the opportunity to further interpret the data. A letter of support for this grant proposal from each Watershed Council partner has been attached.

Related Work
In a separate but related project, Xerces intends to work with the EPA to provide taxonomic laboratories with RIVPACS-ready formats, eliminating the need for formatting of future data by the Watershed Councils and other users. However, there is a lot of existing data that needs to be converted, which is why the EPA strongly supports this partnership between OWEB, DEQ, Xerces, and Watershed Councils.