Angler catches of white crappie Pomoxis annularis and the abundance of adult white crappies in cove rotenone samples decreased significantly in Chickamauga Reservoir from 1970 through 1989. Conversely, densities of larvae and young of year increased (nonsignificantly) during this period. In the 1970s, year-class strength was variable, but high young-of-year densities resulted in increased abundance and angler catch rates when the cohorts reached adult sizes. During the 1980s, reproductive success and survival through the first summer were adequate, but few white crappies reached harvestable size. Expansion of aquatic vegetation and resulting changes in fish and invertebrate community structures appeared to be the most important factors affecting survival of young white crappies in Chickamauga Reservoir. Also, low dissolved oxygen conditions associated with a 1985–1988 drought may have limited survival of age-1 and older white crappies. Prior to 1988, white crappies were the predominant Pomoxis species (over 90%) in Chickamauga Reservoir; in 1988 and 1989, however, juvenile black crappies P. nigromaculatus made up over 80% of crappies collected. This shift in dominance was judged to be related to the expansion of aquatic macrophytes. White crappies have continued to dominate angler catches. Continuing creel and population surveys will be required to determine if the harvest of black crappies will offset the decline in white crappie stocks, or if high juvenile mortality also will affect black crappies.
No takes yet. Share an insight, caveat, or question.
McDonough et al. (1991) studied this question.