Comparative Influences of Abiotic Variables on Seasonal Abundances of Hybrid Striped Bass and White Bass in the Grand Lake Tailwater, Oklahoma

ABSTRACT We sampled hybrid striped bass Morone saxatilis ♀ × M. chrysops ♂ and white bass M. chrysops in the Pensacola Dam tailwater of Grand Lake, Oklahoma, using gill nets at about monthly intervals from January 1988 to July 1989 to assess temporal changes in their abundances in the tailwater and to determine and compare relations between their abundances and changes in selected abiotic variables. Hybrid striped bass and white bass moved into the tailwater during spring and dispersed downstream after the spawning season. Abundances of hybrid striped bass were associated with dam discharge volumes during the month prior to sampling, water temperatures of 15–16°C, and photoperiod intervals of 825–850 min of daylight. Peak white bass abundances were associated with water temperatures of 13°C, photoperiod intervals of 800 min, and dam discharges during the preceding month. Dissolved oxygen concentration had no significant effect on either fish. During periods of peak abundance, both taxa were most abundant ...