Effects of Sedimentation on the Profundal Benthic Macroinvertebrates of a Great Plains Reservoir

Abstract

Reservoir sedimentation has become a large and pervasive problem throughout the entire United States. Sedimentation gradually destroys and eliminates the services for which reservoirs were constructed (flood protection, water storage, and recreation), yet sedimentation is also an ecological problem. Organisms that depend on the deep parts of lakes cannot survive if their habitats are being buried by sediments. Perry Lake, in northeastern Kansas, has lost 23% of its original volume. Sediment thicknesses (depth of sediment accrued since lake formation) in the main lake range from 2–140cm, and upper portions of the lake have become unnavigable. To measure the effect of sedimentation the diversity and density of profundal invertebrate macrofauna were sampled. Thirteen taxa were collected and assemblages were dominated by oligochaetes, midges (chironomidae), and the Phantom Midge Chaoborus. No significant associations between sediment thickness and invertebrate metrics were found, however sediment size was cor...