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Fifteen Years of Stream Monitoring in EMAP: The Evolution of Design, Indicators and Assessment

J.L. Stoddard 1, S.G. Paulsen 1, D.V. Peck 1, P.R. Kaufman 1, A.R. Olsen 1, A.T. Herlihy 2, J. VanSickle 1, R.M. Hughes 2, B.H. Hill 3, D.P. Larsen 4, J.M. Lazorchak 5, F.H. McCormick 6, S.A. Peterson 1, P.L. Ringold 1, T.R. Whittier 2, D.J. Klemm 5

1 US EPA, Western Ecology Division, Corvallis, Oregon
2 Department of Fish and Wildlife, Oregon State University, Corvallis, Oregon
3 US EPA, Mid-Continent Division, Duluth, Minnesota
4 Pacific States Marine Fisheries Commission, c/o US EPA, Corvallis, Oregon
5 US EPA, Environmental Research Center, National Exposure Research Laboratory, Cincinnati, Ohio
6 US Forest Service, Environmental Sciences Research, Olympia Forestry Sciences Laboratory, Olympia, Washington

The monitoring of flowing waters in EMAP began in the Mid-Atlantic in the spring of 1993. In the 15 years since those first samples were collected, the tools and techniques of stream monitoring and assessment have evolved considerably. From the early days of EMAP hexagons, designs have moved on to spatially balanced Generalized Random Tessellation Stratified (GRTS) designs. From simple biological metrics, like EPT richness, EMAP has moved on to a process for building sophisticated Indices of Biotic Integrity (IBIs) and predictive models (O/E indices). EMAP’s approach to the monitoring of physical habitat has become an accepted standard for the quantitative assessment of in-stream and riparian condition; EMAP continues to develop new methods for detecting the departure of physical habitat from reference conditions. The quantification of reference condition, originally only an after-thought in EMAP, has now become an endeavor almost equal in effort to the probability surveys themselves. EMAP has pioneered the regional monitoring of biological stressors, notably fish tissue contaminants and non-native/invasive species. For the complete suite of chemical, physical and biological aquatic stressors, where EMAP was originally satisfied with a simple ranking of extent, assessment methods have progressed to the quantification of relative risk; research on methods to combine measures of the relative extent and relative risk represented by specific stressors continues.

In this presentation, we will trace some of the important innovations in stream monitoring that have occurred in EMAP, culminating in 2005 with the first national probability survey of stream condition, the Wadeable Stream Assessment. Despite the considerable progress, EMAP stream and river monitoring is not a mature science, and continues to develop. The new challenges facing us, as well as some of the next steps in the development of solutions to old challenges, will also be discussed.

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