Atlantic cod are increasingly farmed in land-based and sea-cage systems, with welfare challenges around crowding, cannibalism, light regimes, and slaughter methods.
Crowded cod experience elevated cortisol, immune suppression, and increased susceptibility to disease including vibriosis and Aeromonas infections. Fin damage from aggression is widespread in intensive systems. Light manipulation to control spawning timing disrupts natural circadian rhythms. Pre-slaughter crowding and conventional stunning methods (electrical and percussive) may not achieve immediate insensibility in all individuals. Improved tank design with hiding structures and lower stocking densities reduce aggression.