Assessment of Riparian Management Practices in Northeastern Oregon

Assessment of Riparian Management Practices in Northeastern Oregon

Summary

Understanding the interactions of benthic macro-invertebrates and the river as a habitat is important in the conservation and restoration of the unique systems of the Pacific Northwest. This project utilizes benthic macro-invertebrates as bio-indicators of habitat quality in three types of sites on the Umatilla River in Eastern Oregon: reference sites, test sites, and restoration sites. By comparing the assemblages of invertebrates between the three site types, relative to location on the river, and the environmental conditions at the sites, it is anticipated that any relationships identified may be used to create a predictive model describing habitat quality.

Objectives/Performance Targets

The objective of this study is to utilize assemblages of aquatic macro=invertebrates for bio-monitoring and assessment of habitat quality in the Umatilla River, eastern Oregon. By comparing samples of macro-invertebrates taken in three site types (agricultural, easement and reference), we hope to be able to build a model based on expected and observed diversity and relative abundance. The environmental parameters of each site, including water chemistry, local vegetation, substrate types etc are also taken into consideration when comparing the invertebrate assemblages, in an attempt to better understand the types and impacts of non-point source pollution in agricultural ecologies. This information will be useful in restoration attempts as well as contributing to a larger body of knowledge in the monitoring of freshwater aquatic systems in the Pacific Northwest.

Accomplishments/Milestones

In the two summers of WSARE funding, we were able to complete two sample sets, with the taxa identification process for the 2006 samples completed. The environmental parameter data has also been compiled and is in the process of analysis with the statistical tools we are incorporating in our study. With the completion of the 2007 taxa identification, which is anticipated this spring, we will have three complete sample sets, and will be able to begin tests for signals in the data that indicate impacts on the community structure that may attributed to non-point source pollution resulting from agricultural runoff.

Impacts and Contributions/Outcomes

The impacts of this research in the communities adjacent to the Umatilla River will assist in planning for future restoration attempts, and in conservation of regions less affected by agriculture. This river runs through land owned by the Confederated Tribes of the Umatilla Indian Reservation, and working with the fisheries scientists employed by the CTUIR has opened avenues of communication that will provide better public understanding of the impacts of agriculture on the river, and more broadly on the salmon that are traditionally a part of the CTUIR culture. Beyond the CTUIR, the data provided by this study will contribute to a larger body of knowledge that may affect the regulations for management in river systems, to decrease impacts on the natural processes and functions and better preserve the habitat.

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