sedimentation, prairie pothole, macroinvertebrate, metrics
The Clean Water Act aims to maintain the chemical, physical, and biological integrity of the nation’s waters. Sedimentation is a major pollutant to South Dakota lakes and sources of sedimentation will likely increase as more rangeland is converted toward production of corn and soybeans in South Dakota. This study examined the influence of experimental sediment loads on aquatic macroinvertebrate communities in a prairie pothole lake. Ten emergent macrophyte beds and ten rocky shoreline plots were treated with soil to simulate an annual sediment load of 25 kg/m2. Plots were treated and sampled during the summers of 2005 and 2006. Invertebrates were subsampled, identified, and classified into habitat and feeding guilds. A total of 129 genera were identified throughout the experiment. Macrophyte beds contained an average of 23 genera and rocky shores contained an average of 18 genera. Sedimentation significantly decreased the percentages of collector-gatherers and sprawlers. Percentages of gliders, swimmers, and scrapers increased with the addition of sediment. Macrophyte beds had an increase in Ephemeroptera, Trichoptera, and Odonata richness following sedimentation. The percentage of sprawlers in rocky shorelines was significantly decreased due to sedimentation. We recommend that further studies should examine possible threshold levels of increased sediment that could affect macroinvertebrate communities.
Proceedings of the South Dakota Academy of Science
Dozark, Kristopher G. and Troelstrup, N. H. Jr., "Macroinvertebrate Communities and Their Responses to Regional Sediment Loads in Two Habitat Type of Oak Lake, A Prairie Pothole in Eastern South Dakota" (2008). Oak Lake Field Station Research Publications. 11.