The transition of salmon smolts from freshwater hatcheries to sea cages is a critical and stressful period. Welfare during this phase significantly affects subsequent survival and health.
Smolt welfare during sea transfer is a concentrated welfare event that sets the trajectory for the entire production cycle. Smolts transferred under poor conditions - overcrowding, oxygen depletion, rough handling - enter their sea environment already stressed and physiologically compromised. Their immune systems are suppressed at exactly the moment they face maximum sea lice challenge. Investment in transport welfare - appropriately sized live haul trucks, oxygenation systems, minimised journey times and careful timing within the smoltification window - is both a welfare improvement and a production investment, since healthy smolt entry directly improves survival through the sea phase.