Importance of Reservoir Inflow in Determining White Bass Year‐Class Strength in Three Virginia Reservoirs

The relationship between spring inflows and the year‐class strength of white bass Morone chrysops was examined in three main‐stem Virginia reservoirs. The catch of age‐1 white bass in fall gill‐net samples from 1980 to 1998 was used as an index for year‐class strength in Claytor Lake and Kerr Reservoir. Claytor Lake was sampled by electrofishing during the spring spawning run in 1996, and the residuals associated with catch‐curve regressions were computed to estimate year‐class strength. In Leesville Reservoir, white bass recruit to gill nets at age‐0; therefore, the catch per effort of age‐0 white bass was used as an indicator of year‐class strength. Strong year‐classes (≥0.03 fish/9.29 m2 of gill net) were rare in each reservoir. In Claytor Lake, strong year‐classes were produced in 1987 and 1993, both years of high spring inflows. Lake inflows during April were also positively related to the year‐class strength of white bass in Kerr and Leesville reservoirs and explained about 90% of the variation in age‐1 catch per effort. In all reservoirs, poor or missing year‐classes were most common during years with low flow. If sporadic white bass year‐class strength is partly due to climatic conditions, then equations derived to forecast year‐class strength should facilitate decisions about stocking during low‐flow years or adjusting regulations to optimize the use of available resources.