The welfare challenges of transporting live fish - from smolt transfers to market fish - and best practice for minimizing stress and mortality.
Fish are transported alive at multiple points in their production cycle - from hatchery to grow-out, between grow-out sites, and to processing. Each transport event involves netting, crowding, oxygen depletion, and physical handling that are highly aversive. Fish transport stress triggers a cascade of physiological responses including cortisol release, oxygen consumption increase, and immune suppression that can persist for days. Best practice transport includes pre-transport fasting, appropriate density, continuous oxygenation, and minimal handling - but these practices are not universally applied.