HR: 16:15h
AN: NB44B-04    [Abstracts]
TI: Separating the Effects of Fine Sediments From Those of Nutrients in Agricultural Streams
AU: * Griffith, M B
EM: griffith.michael@epa.gov
AF: National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AU: Daniel, F B
EM: daniel.bernie@epa.gov
AF: National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AU: Morrison, M A
EM: morrison.matthew@epa.gov
AF: National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AU: Troyer, M E
EM: troyer.michael@epa.gov
AF: National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AU: Lazorchak, J M
EM: lazorchak.jim@epa.gov
AF: National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AU: Schubauer-Berigan, J P
EM: schubauer-berigan.joseph@epa.gov
AF: National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AU: Schultz, C
EM: schultz.christopher@epa.gov
AF: National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 United States
AB: Increased inputs of both fine sediments and nutrients to streams are associated with alterations of catchment land cover. However, the mechanisms by which altered land cover causes increased inputs differs between sediments and nutrients. This results in variation in the relative roles of these stressors in reducing biotic integrity in different stream reaches. Therefore, research that differentiates the relative effects of these stressors on biotic communities can guide efforts to ameliorate these effects. Using data collected from 1999 to 2003 in 35 tributary reaches in the Little Miami River basin, Ohio, we assessed the relationships between nutrients, bedded fine sediments, and community metrics for periphyton, macroinvertebrates, and fish. Periphyton exhibit the most distinctive responses to nutrients and sediments and are at least partially responsible for the effects observed in macroinvertebrates and fish. The positive relationship between periphytic biomass and increased nutrients affects variation in dissolved oxygen, whereas the negative relationship between periphytic production and increased fine sediments affects trophic resources, particularly for macroinvertebrate grazers. Attention to such contrasting effects can guide the selection of community metrics that can better discriminate the relative severity of these two stressors in streams.
DE: 1871 Surface water quality
DE: 4845 Nutrients and nutrient cycling
DE: 4863 Sedimentation
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly