δ15N of Chironomidae: an index of nitrogen sources and processing within watersheds as part of EPA’s National Aquatic Resource Surveys


J Renee Brooks, U.S. Environmental Protection Agency, Pacific Ecological Systems Division, Corvallis, United States, Jana Compton, U.S. Environmental Protection Agency, Office of Research and Development, Corvallis, United States, Alan Herlihy, U.S. Environmental Protection Agency, Pacific Ecological Systems Division, Freshwater Ecology Branch, Corvallis, OR, United States, Daniel J Sobota, Oregon Department of Environmental Quality, Portland, United States, Amanda Nahlik, US Environmental Protection Agency, Pacific Ecological Systems Division, Corvallis, United States and Marc Weber, U.S. Environmental Protection Agency, Office of Water, Corvallis, United States