The Influence of Adult Largemouth Bass Abundance on Trends in Reproductive Output

Loss of nesting Largemouth Bass Micropterus salmoides can lead to decreased recruitment if production is directly proportional to the number of successful nests.  Using twenty half-acre ponds in a mid-latitudinal, Midwestern complex, we assessed whether recruitment of age-0 Largemouth Bass was proportional to adult abundance.  Densities ranged from two to eight adult pairs per pond, and production was measured as both number and weight of age-0 fish harvested during fall draining.  Bluegill adults were not included in the pair comparisons but were subsequently evaluated at a static adult level (4 pairs in every pond).  Ponds tended to be either turbid with all-mud bottoms or heavily vegetated, and these conditions were evaluated in relation to Largemouth Bass production.  Total number of young was not influenced by the number of spawners.  Vegetated ponds produced significantly more young than turbid ponds, but total weight of young did not differ by pond type.  Thus, growth of age-0 bass was strongly density dependent.  The presence of bluegill did not have a significant effect on number nor total weight.  We have confirmed that habitat influences juvenile survival and we also conclude that the number of nests is not an effective predictor of recruitment.