Book Description
Dike structures, designed and installed by the U.S. Army Corps of Engineers in the Lower Mississippi River, can modify river geomorphology, discharge rates, and sediment movements within the river. These changes in the river's characteristics, plus the presence of the dikes themselves, result in shifts in types, sizes, and variety of aquatic habitats on a yearly basis. At low water river stages, isolated dike pools bordered by bars are formed, creating distinct aquatic habitats which are quite variable in size and depth. Fish and water samples collected in two such dike pools as well as from the adjacent river border wee used to determine the importance of dike pool habitats to fish communities during a low water period of 1980. Hydrological results indicate that overall differences in water quality were easily distinguishable once stratification began. Surface readings of dissolved oxygen, temperature, and pH were generally higher in the pool habitats than in the main channel. As depth increased, the opposite was true for dissolved oxygen, temperature, and pH. Conductivity at the bottom in the pools during isolation was much higher than in the main channel.