The purpose of this study was to determine if habitat suitability criteria developed in the summer months for sma11mouth bass were transferable among streams representing different eco regions. Habitat suitability criteria were developed for depth, mean column velocity, cover and substrate for two size classes of sma1lmouth bass, 100-199mm and >200mm, in the North Anna River and Craig Creek, Virginia. Criteria that accurately describe habitat selection by a species or guild in a system different from where the criteria were developed are said to be transferable to that system. The transferability of suitability criteria between the North Anna River and Craig Creek, as well as depth and velocity criteria from Minnesota, the Huron River, Michigan and the Upper James River, Virginia, to the North Anna River and Craig Creek were tested using a 2x2 contingency table analysis. Depth criteria for the smaller sizes of sma1lmouth bass did not transfer well between regions; 4 of the 8 transferability tests (50%) failed. Depth criteria for larger sma1lmouth bass transferred to the North Anna River and Craig Creek in all cases. Velocity criteria developed for the smaller size classes did not transfer well among regions; only 3 of the 8 transferability tests were positive. Likewise, velocity criteria for larger sizes of smallmouth bass did not transfer well; only 1 of 8 tests were positive. General criteria were developed for depth and mean column velocity by averaging the suitability values reported from this and 3 other studies. General depth and velocity criteria transferred well to the North Anna River and Craig Creek for both the larger and smaller size classes of smallmouth bass; all depth tests were positive and 3 of 4 velocity tests were positive. The improved success of transferability warrants investigation of developing general criteria for smallmouth bass. Cover criteria for both size classes of smallmouth bass were transferable from the North Anna River to Craig Creek but not vice versa. Substrate heterogeneity criteria were not transferable between the North Anna River and Craig Creek for either size class of smallmouth bass. Criteria developed for the percentage of substrate particles >15cm (smallmouth bass >200mm only) were transferable from Craig Creek to the North Anna River but not vice versa. The transferability of habitat suitability criteria among regions was inconsistent and it is recommended that site-specific criteria be developed for each stream to which habitat assessments are applied. Additionally, nose velocities used were more consistent between the North Anna River and Craig Creek than were mean column velocities used. Hence, it is recommended that information on nose (focal point) velocities be incorporated into habitat studies to more accurately describe smallmouth bass velocity requirements. / Master of Science

Two species of black bass, smallmouth bass Micropterus dolomieu and spotted bass Micropterus punctulatus, are sympatric in both riverine and impounded sections of the New River, Virginia. Resource use (habitat and diet) by the two species was investigated to determine patterns and extent of resource partitioning between them and how those patterns might differ between lotic and lentic environments. Individual fitness indicators (i.e., growth and body condition factor) were also measured to assess performance of populations of the two species in the study areas. Fitness indicators suggested relatively good performance of both species in both river and impoundment, which implied that competitive pressures were not intense. Diet analyses indicated fairly high overlap in prey types consumed. High fitness combined with considerable diet overlap suggested that food availability was adequate, and that segregation in this impounded river system was not on a trophic basis. The two species were found to segregate spatially, with spotted bass predominant in the impoundment and smallmouth more abundant in the river. Spatial segregation was also apparent within both river and impoundment habitat types. / Master of Science