Ball State University, NREM, Muncie, IN 47306
Aquatic macroinvertebrates are an important part of the stream ecosystem as they are a major link in the food chain and indicators of water quality. While macroinvertebrates are usually known to be influenced by pollution levels, they can also be influenced by temperature. This research project examined a wide variety of aquatic macroinvertebrates in the field and how they respond to temperature changes. Data obtained from past macroinvertebrate sampling at nine sites in Delaware County on the Upper West Fork of the White River (WFWR) and its tributary, Buck Creek between 2009 and 2011 was used for analysis. Sites were classified in terms of their summer maximum average daily temperature as one of three types; coldwater (<22 °C), coolwater (22 to 24 °C), and warmwater (>24° C). Macroinvertebrate sampling was conducted using the Indiana Department of Environmental Management (IDEM) Multi-Habitat (MHAB) Macroinvertebrate Collection Procedure from July to August of each year during the high summer months. Aquatic macroinvertebrate temperature sensitivity was analyzed with detrended coorespondence analysis (DCA). The resulting DCA axes were plotted to identify distinct species and site groups (i.e., coldwater, coolwater, and warmwater). ANOVA was used to compare the three temperature groups formed based on DCA axes site scores in order to determine significant differences in species assemblage among temperature groups. The detrended correspondence analysis identified a major community transition by the separation of the three warmwater sites from the cool and cold water sites along the first axis. A second axis showed that there was not much of a community change between coolwater sites and coldwater sites. There was an overall significant difference in site scores for DCA1 (F-value = 25.9, df= 2,6, P = 0.001). The detrended correspondence analysis identified 37 species that were characteristic of warmwater sites and seventeen species that were characteristic of cool and coldwater sites.
[Abstract (DOC)]