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Anderson, R. V. (1989). Environmental aspects of river control in the Upper Mississippi River. Page 74 in M. D. Games, ed. National Meeting of the American Association for the Advancement of Science, New Orleans, Louisiana (USA), AAAS Annual Meeting Abstracts.

The first lock and dam on the Mississippi River was completed in 1913 at Keokuk, Iowa. The resulting impoundment and flooding and leveling of the floodplain forest have substantially modified the river environment. The annual hydrologic regime has been changed with increasing flood frequency and elevation. The loss of floodplain habitat has altered energy flow and nutrient cycles by removing extensive floodplain/riverine interactions and thus altering food web structures. Bottom substrate has become finer grained with a shift in benthic organisms from cling and sprawling to burrowing forms. As silt accumulates in impounded river reaches aquatic vascular plants begin to grow dramatically reducing benthic production and shifting community composition. Macrophyte beds further accelerate siltation which results in a succession of plant communities ultimately reducing the permanent aquatic habitat. Present management programs in the Upper Mississippi River are being developed which should mitigate some of these environmental effects.