Feasibility of Using Historic Disposal Areas, Upper Mississippi River, to Evaluate Effects of Dredged Material Disposal on Community Structure of Benethic Organisms.

摘要

Environmental studies addressing the effects of dredged material disposal on the community structure of benthic organisms in freshwater systems are extremely scarce. Most studies of this general nature have been conducted in marine environments and have emphasized short-term effects, rather than long-term effects. The community structure of benthic organisms occurring in four historic disposal areas (1969, 1972, 1973, and 1974), Pool 25, Mississippi River, was investigated in June 1974 to determine if these areas, with known disposal histories, could be evaluated in terms of effects related to the disposal of dredged material. Concurrently, unaffected control areas were also studied to differentiate between effects related to disposal activities and those associated with natural changes. The community structure of benthic organisms was described in terms of numerical abundance, biomass, species diversity, and evenness indices. Substrate types and water depths were also described for each sampling area.