Assessment of Floating Vertical Raceways for the Culture of Phase-II Hybrid Striped Bass

摘要

A floating vertical raceway is a system designed to provide a constant, unidirectional flow of water to fish confined in a flexible raceway that is suspended vertically in the water column. This study evaluated the potential of floating vertical raceways for the culture of phase-II sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) reared at two densities (125 and 188 fish/m3). Fish with a mean starting weight of 0.7 g were fed a diet containing 40% crude protein to satiation for 121 d. Fish in the low-density treatment reached a significantly higher final mean weight (160.0 g) than those in the high-density treatment (136.9 g). Survival was also significantly higher in the low-density treatment (81.1%) than in the high-density treatment (73.8%). No significant differences in water quality were detected for dissolved oxygen, total ammonia, un-ionized ammonia, or temperature between high-density and low-density treatments. Unlike the surrounding reservoir, water temperature inside the raceways remained destratified throughout the growing period. Based on the performance of fish, the high water quality maintained inside the enclosures, and ease of use, the floating vertical raceway system offers considerable promise as an alternative rearing system for deepwater impoundments.