ABSTRACT
To make landbased salmon farming economically feasible, production must be highly intensive. It is therefore necessary to oxygenate the water, and as a consequence of vital importance to have sufficient knowledge about the oxygen demand of the fish and the factors affecting this demand.
The oxygen consumption of post-smolt Atlantic salmon was monitored in growth trials at three landbased farms ranging from pilot scale to a large commercial scale (25, 500 and 1000 m3 tanks).
Measured data were compared to predicted data from existing oxygen consumption models, using temperature and fish size as determining factors. Deviations from the model predictions are discussed, as are other possible affecting factors such as fish density, water supply, water current velocity, seasonal light fluctuation, feeding regime, specific growth rate (measured rate and deviations from expected), and scale of operation.
Water current velocity was found to be the most important factor affecting the oxygen consumption. Special emphasis is placed on the role of diurnal fluctuations of specific oxygen consumption. The relationships found may serve as a basis for dimensioning future landbased salmon farms and oxygenation systems.
