Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2008
Publication Date: June 12, 2008
Citation: Gillespie, R.B., Smiley, P.C., King, K.W., Huang, C. 2008. Relationships of macroinvertebrate communities with nutrients, pesticides, and physicochemical parameters in channelized headwater streams in Indiana and Ohio. American Society of Limnologists and Oceanographers Summer Meeting. p. 29. Technical Abstract: Many headwater streams in the midwestern United States have been modified or constructed to transport agricultural runoff downstream. Effective implementation of agricultural conservation practices to reduce nutrient and pesticide loadings requires information about the influence of water chemistry on stream communities. We evaluated the relative influence of nutrients, pesticides, and physicochemical variables on macroinvertebrate communities in channelized headwater streams in Cedar Creek, Indiana and Upper Big Walnut Creek, Ohio. We sampled water chemistry and macroinvertebrates within 20 sites from July 2005 to November 2006. Preliminary multiple regression analyses suggested that macroinvertebrate communities were more strongly correlated with nutrients than pesticides or physicochemical variables. Specifically, taxa richness (r2 = 0.651; P < 0.05) and percent Chironomidae (r2 = 0.507; P <0.05) were strongly correlated with mean nitrate-nitrite concentrations, while percentage EPT was strongly correlated (r2> = 0.894; P < 0.05) with soluble reactive phosphorus concentrations. Our results suggest that conservation practices that alter nutrient loadings will have a greater influence on macroinvertebrate communities in channelized headwater streams in Indiana and Ohio than those practices that alter pesticide or physicochemical variables.