Habitat, Accessibility, and Watershed Variables as They Relate to Largemouth Bass and Bluegiii in Mississippi's National Forest Impoundments

Small watershed impoundments provide the principal recreational fishing opportunities within national forests in Mississippi. Relative abundance and stock structure of bluegiii (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) were assessed by electrofishing 18 national forest impoundments during spring 1990, autumn 1990, and spring 1991. There were no significant yearto- year or seasonal differences in catch per unit effort (CPUE) or proportional stock density (PSD) for either species. Mean CPUE for stock-size largemouth bass (total length ≥ 200 mm) ranged from 8.2 to 9.7 fish/hour of electrofishing and mean PSD ranged from 14.0 to 22.5. Mean CPUE for stock-size bluegill (total length ≥80 mm) ranged from 38.7 to 45.0 fish/hour and mean PSD ranged from 21.5 to 21.8. Twenty-five habitat, accessibility, and watershed variables were evaluated by multiple regression techniques to determine factors that significantly described largemouth bass and bluegiii CPUE and PSD. Conductivity, population of the nearest town, and the percentage of upland hardwoods in the watershed accounted for 73% of the variation in bluegiii CPUE, while 57% of the variation in largemouth bass CPUE was explained by surface dissolved oxygen, distance to the nearest paved road, and the percentage of wetlands in the watershed. Variation in bluegiii PSD was best described by alkalinity, distance to the nearest paved road, and chlorophyll a concentration (R2 = 61), while the population of the nearest town, chlorophyll a concentration and the percentage of upland hardwoods in the watershed accounted for 67% of the variation in largemouth bass PSD. These models suggest that emphasis should be placed on impoundments located in watersheds comprised principally of hardwoods. Improving water quality (i.e., fertility) of these impoundments should receive priority by fisheries managers, followed by management orientations addressing watershed characteristics and angler exploitation of the fish stocks. Application of fertilization programs with wetlandconnected impoundments should probably be avoided in order to maintain the integrity of wetland characteristics which may be sensitive to artifical nutrient loading.

Starting page
26
Ending page
36
ID
20601