Michael S. Allen, Department of Fisheries and Aquatic Sciences, University of Florida 7922 NW 71st Street, Gainesville, FL 32653; James C. Greene, Frederick J. Snow, Michael J. Maceina, Dennis R. DeVries. Department of Fisheries and Allied Aquacultures, Auburn University, Auburn, AL 36849

Abstract. We examined daily otolith rings and estimated density, age, and growth of age-0 largemouth bass Micropterus salmoides collected from nine Alabama impoundments using shoreline rotenone sampling. In addition, we examined a variety of factors thought to be related to growth and density of age-0 largemouth bass. Reservoirs classified as eutrophic ( 8 mg chlorophyll a/m³) had higher crustacean zooplankton densities, higher larval shad Dorosoma spp. densities, and higher densities and faster growth of age-0 largemouth bass than oligo-mesotrophic reservoirs (<8 mg chlorophyll a/m³). Based on an index of climate for each lake (long-term cooling degree days), reservoirs in the southwest portion of the state had warmer climates, combined with earlier mean largemouth bass swim-up dates; age-0 largemouth bass in these systems exhibited the densities and were among the most rapid growth rates we found. Alternately, peak larval shad densities occurred later in spring in these southwestern reservoirs. Therefore, fast growth and high density of age-0 largemouth bass was related to larval shad spawning dates. Although previous work has shown that larval shad may reduce zooplankton and indirectly inhibit age-0 largemouth bass growth and eventual recruitment, results of this study suggested that recruitment of largemouth bass may be higher in lakes with high larval shad densities than in lakes with intermediate or low larval shad densities. However, timing of larval shad-largemouth bass spawning may be critical to recruitment of largemouth bass, with an early spawn of largemouth bass followed by a late spawn of larval shad yielding strong largemouth bass year classes.