Effects of fish density on growth and smoltification in intensive production of Atlantic salmon (Salmo salar L.)

Parr of Atlantic salmon (Salmo salar) were reared at four different densities (21, 43, 65 and 86 kg fish m− 3) for 100 days in fresh water under conditions where equal specific flow rate was maintained in all density groups (0.3 L kg fish min− 1). Water quality parameters such as oxygen level, pH and CO2 were monitored and kept within recommended values. When ready smolted the fish were transferred to seawater for a further 15 weeks. The findings suggest no negative effects on Atlantic salmon when reared at densities up to 86 kg m− 3 as long as water flow rate, water quality parameters and food rations are within the recommended standards. Maintaining sufficient food supply is important at high densities to avoid negative social interactions.