Closed-containment systems on land
Land-based closed-containment systems (RAS) are increasingly using water recirculation technologies that treat and recycle as much as 99.9% of the water.
Such facilities have only minimal direct hydraulic connection with the environment, and RAS can capture over 98% of the fish waste solids. RAS allows for much greater control of the rearing environment than cages in sea, and makes avoidance of sea lice, and nutrient reclamation possible.
In Norway, landbased smolt production in RAS has expanded considerably, and there is considerable interest in post-smolt production in RAS.