Fishery and Ecological Investigations of Main Stem Levee Borrow Pits Along the Lower Mississippi River

摘要

The 25 borrow pits sampled were distributed along the Mississippi River from New Madrid, Missouri, to near Lutcher, Louisiana. Data on fishes, macrobenthos, water quality, and sediments were collected once in the summer of 1981; topographic surveys of each borrow pit were conducted in 1982. Results of this investigation indicated that main stem levee borrow pits along the Lower Mississippi RIver support abundant and moderately diverse fish and macroinvertebrate populations. Total fish standing stock averaged 600 lb/acre; macroinvertebrate total density and standing stock averaged 2967 organisms/sq m. and 851 mg dry weight/sq m. respectively. Gizzard shad, buffalo, carp, and threadfin shad were the most abundant fishes, but significant numbers of white crappie, sunfishes, and catfishes were also present. The phantom midge, Chaoborus punctipennis, the midge Tanypus stellatus, and tubificid worms were the most abundant macroinvertebrates. Step-wise regression analyses revealed that the duration of annual borrow pit flooding by Mississippi River waters was the single most important positive factor affecting fish and macrobenthos abundance in the borrow pits; mean borrow pit depth, Volume Development Index (a depth factor), and Shoreline Development Index were also significant factors influencing the abundance of some fish and macrobenthos species.