Lower Mississippi River Environmental Program. Report 6. Fish and Benthic Communities of Eight Lower Mississippi River Floodplain Lakes

摘要

The purpose of this study is to obtain baseline data on the fish and benthic communities of eight Lower Mississippi flood-plain lakes, including abandoned channel type I, abandoned channel type II, and oxbow lakes. Fish communities were sampled and evaluated using electrofishing, experimental gill netting, and rotenone. The comparison of fish populations of oxbow lakes and abandoned channel type II lakes illustrated similarity in species occurrence, relative abundance, and length frequency. Abandoned channel type I fish populations were not similar to those of the other two lakes. Fish and population data illustrated that although fish are transient among main channel and floodplain habitats during high-water periods, there are particular habitat types that provide important spawning and nursery areas, forage availability and cover for the majority of the lower Mississippi River fishes when river flow is within the channel top banks. Length frequency analysis showed similarities in size categories of fish from all habitats sampled. Threadfin shad comprised the dominant forage base at most habitats. Year class strength coincides with changing hydrology, and it is therefore impossible to characterize static fish standing stocks from each specific habitat.