The Mobile Basin is a prime example of a system that has undergone extensive channel modification with corresponding declines in the distribution and abundance of the native aquatic fauna. However, many of the declining aquatic species of the Mobile basin may persist within unmodified subbasins. The Noxubee River is a subbasin of the Mobile basin that has had very little alteration throughout its watershed. I investigated the species richness and assemblage structure to determine if the contemporary fish assemblage attributes resembled the conditions represented by historic collections. The findings of this study are important because the Noxubee River has not been extensively investigated since 1983, and the river could serve as refugia for declining riverine species of the Mobile basin. After examination at both local and regional levels, I determined that a diverse contemporary fish assemblage comprising 87 species, similar to historic collections, still persists in the Noxubee River system.

Water resources for Bluff Lake in Mississippi are managed to achieve objectives related to waterfowl, waterbirds, fish, anglers, and Paddlefish (Polyodon spathula). Annually, the reservoir undergoes a nine-stage seasonal drawdown and re-inundation to improve waterfowl habitat. In addition, weekly discharges are released from the water control structure to encourage Paddlefish spawning and migration each spring. However, additional discharges throughout the year may provide additional passage opportunities. In this study, multiple discharge states were evaluated to identify optimal water releases during each drawdown period given reservoir objectives. First, I developed a hydrodynamic model to predict daily changes in lake volume. Second, I defined functional relationships between water surface elevation and management objectives. A structured decision-making framework was then applied to determine the optimum additional discharge strategy. This approach allowed trade-offs between management objectives to be evaluated and optimal water releases to be identified for this multiuse reservoir.

Bats are important components of biodiversity within forested ecosystems. This research addressed habitat characteristics that influence species occupancy and stable isotopes and wing morphology to assess community structure within the Sam D. Hamilton Noxubee National Wildlife Refuge. To meet these objectives, I deployed echolocation recorders, mist-nets and conducted roost checks to capture bat acoustics; fur samples were also collected to measure ratios of carbon (C13/12) and nitrogen (N15/14). Relationships between occupancy, habitat class and features were not apparent for most species. However, Lasiurus and Mytois spp. showed positive relationships with proximity to roads, Lasiurus, positive with stem density and Perimyotis subflavus, negative with basal area. Stable isotope analysis revealed some distinction of trophic niches while wing morphometrics indicated bats of similar wing shape and size show greater trophic overlap. Collectively, these results suggest that habitat management, as current within the study area, will have limited influence on local bat distributions.