Tuesday, August 3, 2010
Exhibit Hall A, David L Lawrence Convention Center
Katie G. Norris, Ecology and Environmental Science, University of Maine, Orono, ME and Ryan W. McEwan, Department of Biology, The University of Dayton, Dayton, OH
Background/Question/Methods Water is an invaluable natural resource to both human and ecological communities, but local and global pollution currently threaten the ecological integrity of river systems. Freshwater rivers in the Midwestern U.S. pass through landscapes that are often highly impacted by anthropogenic factors, particularly urbanization and intensive agriculture. The objective of this research project was to examine the factors influencing biological integrity of the Great Miami River (GMR) in southwestern Ohio, USA. The intent was to 1) track changes in water quality along a rural‐suburban‐urban continuum of watershed land use, 2) examine nutrient loading longitudinally and 3) observe the influence of significant riparian buffers. Data were collected during the course of two continuous river trips starting from the headwaters of the GMR and ending north of Dayton, Ohio. This stretch covers approximately 112km of the river corridor that flows through five Ohio municipalities and a variety of land uses. Sampling locations were selected based on land use conditions including agriculture, urban/suburban and major tributary confluences. Chemical water quality data, habitat evaluations and macroinvertebrate diversity and tolerance data was collected at these sites.Results/Conclusions
For both sampling periods, the chemical data showed a negative correlation between water quality and distance from the headwaters. Similarly, nutrient loading of total phosphate increased with distance from the headwaters. Site habitat quality fluctuated with land use, but on average, the urban sites scored lower than non-urban sites. Urban sites were often channelized and had lower habitat and fewer macroinvertebrate taxa, but rural sites also varied based on land use and riparian width. When habitat quality increased, so did the macroinvertebrate taxa. Overall, ecological integrity, as the combination of chemical, habitat and macroinvertebrate data, was better in rural sites than urban sites but sites varied based on land use. To continue to build a valuable spatial and chronological dataset for the Great Miami River, data must be gathered annually and sampling should include the remainder of the river down to its intersection with the Ohio River. This will assist regional communities in understanding their impact on local and national water quality.
