Beser, Todd M.While water quality is often cited as the main factor that controls the distribution of submersed aquatic macrophytes (SAM) in the Chesapeake Bay, additional factors associated with physical and/or biological disturbances also affect the distribution. At local scales, such as in Saltpeter Creek, a tributary to the Gunpowder River, the thermal effluent from C.P. Crane Power Plant may be an important environmental gradient. I mapped the temperature signature of the effluent in Saltpeter Creek and intensively sampled the plant community structure to investigate the ecological similarity of SAM communities within and across different thermal regimes. I also conducted growth chamber experiments to study how different species and populations sampled from different temperature regimes respond to a controlled temperature gradient. Analyses show that although significant differences in water temperature exist across the study site, differences in temperature do not appear to significantly drive the plant community composition of the system.en-USThesisEnvironmental SciencesSubmersed aquatic macrophytesGunpowder RiverMDthermal effluentChesapeake Baybiodiversity