Submitted to: International Conference on Recirculating Aquaculture
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2004
Publication Date: 7/1/2004
Citation: Brazil, B.L., Silverstein, J. 2004. The impact of recirculated culture water on rainbow trout included in a selective breeding program. International Conference on Recirculating Aquaculture. P.423
Technical Abstract: Water recirculation has the potential to be a significant tool for cold water aquaculture, which has traditionally utilized flow-through culture systems. Increasingly restrictive effluent quality standards and reductions in groundwater quantities suggest that future increases in production intensity can not be supported by current strategies. Water recirculation can address both limitations. As aquaculturists implement selective breeding strategies to increase production efficiency, the question arises whether the fish that grow best in flow through conditions also grow best in recirculation conditions. The National Center for Cool and Cold Water Aquaculture has initiated a selective breeding program with founding populations that have been domesticated and selected for growth in single pass or serial reuse culture systems. As part of the initial evaluation of the existing genetic diversity, fingerling rainbow trout from 3 different strains were stocked and reared in replicated culture tanks operated in either flow-through or recirculation modes. During a 4-month trial period, growth and feed conversion are being evaluated along with comparisons of blood serum chemistry profiles. In addition, the final sample will incorporate a confinement stress to determine the cortisol response of individuals cultured under different water systems. This study will establish whether differences in environmental conditions result in differences in growth, feed utilization, blood serum chemistry, and response to confinement stress. Furthermore, we will determine if the genetic groups growing best under flow-through conditions also perform in a superior manner in a recirculation system, or if there is a genotype by environment (GxE) interaction. A significant GxE interaction would suggest an important distinction for selective breeding programs in flow-through versus recirculating systems.