Hybrid striped bass (Sunshine Bass) were raised in an indoor recirculating aquaculture system incorporating concrete culture tanks, sump tanks, rotating biological contactors and liquid oxygen injection and underground U-tubes for aeration. Fish were anesthetized by two methods after harvest to reduce metabolic activity. Hybrid striped bass were either held in cooled water or water with elevated CO₂ levels prior to sacrificing and filleting. Control fish were filleted immediately or three hours after harvest. The objectives of this study were to determine the effects of these treatments on fillet quality and to develop indicators of quality and shelf life. All fillets were stored at 1-4°C and tested over a 14-day period. Analyses included aerobic plate count, pH determination, texture measurements (Instron), color measurements (L* a* b* scale) and sensory panel evaluations of cooked portions for appearance, taste, odor and texture. Fillets of the cooled water treatment group had the highest pH and were significantly less firm (Instron). Log phase growth and the time for spoilage levels of microorganisms to grow were delayed one day in the CO₂ fillets. In addition, the CO₂ treated fillets were generally rated higher in sensory attributes than the other fillets, especially late in the test period.