The Central Mississippi River states contain the confluences of the Upper Mississippi River with the Ohio, Missouri, and Arkansas rivers. Alteration of these large rivers for transportation and flood control has substantially altered their ecological characteristics, eliminating natural floodplains, sandbars, and meanders, and impeding fish migration routes. Other major tributary rivers include the Tennessee, Cumberland, Kentucky, and Osage, all very large rivers in their own right. Large reservoirs are common in the landscape of this region and have increased recreational opportunities for sportfish as well as many other activities, but typically suffer from dissolved oxygen issues in both the reservoirs and in the release water, [...]