The Morphometry, Benthos and Sedimentation Rates of a Floodplain Lake in Pool 9 of the Upper Mississippi River

Publisher Website
Google Scholar
Abstract
Big Lake is a shallow (mean depth = 0.89 m in 1973) 256-ha backwater lake on the floodplain of the Mississippi River in NE Iowa [USA]. During the summer of 1973 and 1974 Sphaerium and Hexagenia made up 8190 of the benthic macroinvertebrate abundance and 92% of the benthic biomass; both taxa had greatly reduced abundance and biomass within stands of emergent Sagittaria along the lake margin. During July 1974 the Sagittaria net productivity was about 19 g/m2 per day. Between 1896 and 1973 about 76 cm of sediment had accumulated in Big Lake, and the recent sedimentation rate (1964-1974) was about 1.7 cm/yr. The calculated annual reduction in lake volume of about 37,400 m3/yr suggests that the physical and biological components of this productive aquatic habitat will be greatly modified during the next few decades.