Spatial Patterns of Macroinvertebrates on the Upper Mississippi River System.

Abstract

Abstract : The most widespread annual collections of benthic (bottom dwelling) macroinvertebrates in the Upper Mississippi River System (UMRS) are now being made as part of the Long Term Resource Monitoring Program (LTRMP). Long-term monitoring is necessary to better understand the conditions needed to support viable macroinvertebrate populations at levels adequate to sustain native fish and migrating waterfowl. In 1992, the long-term monitoring of select taxa began in Pools 4, 8, 13, 26 and the Open River Reach of the Upper Mississippi River and in La Grange Pool of the Illinois River. Mayflies (Ephemeroptera), fingernail clams (Sphaeriidae), and Asiatic clams (Corbicula sp.) were first selected for sampling, followed by midges (Chironomidae) in 1993, and zebra mussels (Dreissenapolymorpha) in 1995.