Shannon Brewer (Ph.D.) Advisor: Dr. Charles F. Rabeni Many Missouri streams are perceived to be deteriorating and resulting in declines of sportfish populations (e.g., smallmouth bass Micropterus dolomieu). Protecting and restoring fish populations on a regional basis are most effective if the multi-scale factors for the relative quality of a fishery are known. I spatially linked statewide historical fish collections to natural-occurring landscape and in-channel features in a geographic information framework to identify each stream reach’s potential in Missouri to support a smallmouth bass population. Subsequent objectives will use combinations of the most significant features from these models to investigate land-use impacts at multiple spatial scales. Objectives will address the influence of land-use (forest, pasture, and urban) on smallmouth bass densities in stream reaches with similar natural-occurring conditions (soil texture, soil permeability, stream size), the role of groundwater in mitigating land-use effects, and channel unit and microhabitat use in reference and impacted stream reaches. These combined efforts will result in a better understanding of the biological potential for smallmouth bass populations in stream segments in the Ozark physiographic region and how natural-occurring conditions interact with watershed land use to alter the relative quality of the fishery. Publications: Brewer, S.K. and C.F. Rabeni. In Press. Seasonal and diel habitat shifts by juvenile ictalurids in a flow-regulated prairie river. The American Midland Naturalist. Brewer, S.K., C.F. Rabeni, and D.M. Papoulias. 2007. Comparing histology and gonadosomatic index for determining spawning condition of small-bodied riverine fishes. Ecology of Freshwater Fish Online Early Edition. Brewer, S.K., C.F. Rabeni, S.P. Sowa, and G. Annis. 2007. Natural landscape and stream segment attributes influencing the distribution and relative abundance of riverine smallmouth bass in Missouri. North American Journal of Fisheries Management 27(1): 326-341. Brewer, S.K., D.M. Papoulias, and C.F. Rabeni. 2006. Spawning habitat associations and selection by fishes in a regulated prairie river. Transactions of the American Fisheries Society 135(3): 763-778. Brewer, S.K., C.F. Rabeni, and D.C. Heimann. 2005. The importance of day versus night fish sampling for instream-flow determinations. Proceedings of the Southeast Association of Fisheries and Wildlife Agencies 59: 336-347. Heimann, D.C., J.M. Richards, S.K. Brewer, and R.D. Norman. 2005. Quantification of fish habitat in selected reaches of the Marmaton and Marais des Cygnes Rivers, Missouri. U.S. Geological Survey Scientific Investigations Report 2005-5180.