Temperature and Dissolved Oxygen Habitat Use by Striped Bass and Hybrid Striped Bass in Claytor Lake, Virginia
John M. Kilpatrick and John J. Ney
Abstract.—We compared the habitat selection (temperature and dissolved oxygen) of striped bass (STB) Morone saxatilis and hybrid striped bass (HSB; palmetto bass [male white bass M. chrysops × female striped bass]) in Claytor Lake, Virginia. Striped bass (n = 28) and HSB (n = 33) were implanted with temperature-sensitive radio tags and tracked biweekly for a period of 19 months to record position and habitat use. Striped bass averaged 715 mm total length (range 533–940) whereas HSB averaged 547 mm total length (range 460–659). Habitat separation was most apparent in the warm season months of June through August. During this period, when deoxygenation of the metalimnion and hypolimnion was not limiting, STB and HSB segregated according to apparent temperature preferences, with HSB selecting warmer temperatures. As deoxygenation progressed, HSB and especially STB were forced into warmer strata than preferred. Results from this study suggest that if favorable dissolved oxygen levels are maintained, STB and HSB will vertically segregate during summer stratification. Temperature selection and qualitative observations of fish mortality in summer indicated that adult HSB would be less vulnerable than adult STB to a temperature–dissolved oxygen squeeze in summer and its detrimental effects.