Sea cage design significantly influences Atlantic salmon welfare through effects on water quality, stocking density, and the ability to perform natural swimming behaviour.
Salmon in poorly designed cages with inadequate water circulation experience chronic hypoxia at depth. High stocking densities cause aggression, fin damage, and chronic stress that suppress immunity. Cage design that promotes good water flow, appropriate depth, and access to optimal oxygen levels directly improves salmon welfare. Light regime management for production also affects welfare through disruption of natural circadian rhythms. Welfare-conscious cage design is an important component of improving salmon welfare at scale.