Habitat Use, Movements, and Exploitation of Striped Bass and Hybrid Striped Bass in Claytor Lake, Virginia
The comparative performance of striped bass Morone saxatilis (STB) and hybrid striped bass M. saxatilis x M. chrysops (HSB) was evaluated in Claytor Lake, Virginia. This study assessed: 1) habitat use versus habitat availability for STB and HSB; 2) seasonal movement patterns, movement rates, and emigration rates of STB and HSB; and 3) angler catch rates of STB and HSB in Claytor Lake.
In general, STB and HSB used similar habitats throughout this study. However, HSB used warmer (2-3'aC) water than STB during spring of 2001 and 2002. During the summer months, fish selected the coolest water temperature available that contained adequate (> 2.0 mg/L) dissolved oxygen. Striped bass habitat was more degraded than HSB habitat during summer stratification of both years.
Both moronids exhibited similar seasonal movement patterns. Upstream spawning migrations took place in March at 9-10'aC. Summer habitat was restricted to the lower 1/3 of Claytor Lake, whereas fish used the entire reservoir during other seasons. Minimum daily movement rates were similar between species and seasons (0.2-0.5 km/h). Hourly movement rates were also similar between species (0.2-0.3 km/h). One tagged fish from the reservoir was recovered below the dam, suggesting low rates of emigration.
Poor tag return rates by anglers limited confidence in estimation of exploitation rates. However, based on estimated natural and handling mortality rates and tag-reporting rates, estimated annual fishing mortality was 26% for STB and 14% for HSB, lower than rates found in Virginia′s Lake Gaston and Smith Mountain Lake.