Optimization of growth performance of juvenile cod by applying environmental regulation and water quality control

The production of Atlantic cod will in the future be entirely based on year-round supply of juveniles reared in intensive land-based systems at high densities. The profitability of such systems are governed by the exploitation rate of the fish holding cap acity (fish tanks and water pumping), growth and turnover in production. To effectively exploit such systems it is necessary to obtain detailed knowledge on the impact of key rearing factors such as growth performance, food conversion efficiency stocking density and fish welfare. The current proposal will, through a series of large- and laboratory-scale experiments, provide the cod aquaculture industry with a strategy that will significantly reduce production time of juvenile cod and thus reduce productio n cost per kg market sized fish. The project will: 1) investigate the impact of key environmental parameters (temperature and photoperiod) 2) identify important water quality parameters and their influence on growth performance on 2 - 150 g cod from breedstocks of different geographical origin and 3) suggest an optimal stocking strategy for cod throughout the juvenile phase (2-500 g). The potential effects of environmental manipulations in the early juvenile phase on subsequent growth and maturation will also be investigated in a commercial ongrowi ng phase in sea cages.