As a part of the ecological research on high-gradient streams in the Yazoo River Basin of Mississippi, four man-made pools below grade-control (low-drop) structures and four naturally occurring scour-hole pools were sampled for fish composition by the rotenone method. Tillatoba and Long Creeks were chosen because of the presence of grade-control structures used as structural management practices for control of channel erosion from head cutting and because the region has been included in a comprehensive land treatment and channel stability project (Demonstration Erosion Control Project (DEC) of the Yazoo Basin). Differences in the fisheries characteristics of the two pool habitats were expected because of differences in their relative stability, bottom substrate, and pool life expectancy. Natural scour holes yielded 0.06 kg/m3 of fish from 39 species; 0.018 kg/m3 were considered harvestable. Twenty-nine species of fish in man-made pools yielded 0.06 kg/m3, with 0.025 kg/m3 being harvestable. Channel catfish (Ictalurus punctatus) and carpsucker (Carpiodes carpio) were the dominant fish by weight in both pool habitats. Bullheads (Ictalurus sp.), sunfish (Lepomis sp.), and spotted bass (Micropterus punctulatus) were important in natural pools, and bullheads, largemouth bass (Micropterus salmoides), and sunfish were dominant in man-made pools. Length frequency distributions indicated that there was better growth of many species and more stable reproducing populations of forage fish in man-made pools, although they yielded somewhat fewer species. While such pools will not support heavy sport fishing pressure, drop structure pools have several advantages over most natural scour holes in their fisheries characteristics. They also offer protection from stream channel degradation while providing additional habitat diversity.
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Cooper et al. (1987) studied this question.