Atlantic cod aquaculture has been developed as wild cod stocks collapsed, but the species' specific welfare needs — including light sensitivity, social behaviour, and stress responses — create significant challenges in farming.
Farmed cod welfare is compromised by conditions that the species evolved not to tolerate. The prevalence of cataracts — reaching 90% in some farms — indicates widespread nutritional or environmental inadequacy; cataractous cod have reduced ability to find food and show altered behaviour. Continuous artificial lighting used to manipulate photoperiod disrupts circadian rhythms with unknown but potentially significant welfare impacts. Cannibalism-driven size sorting requires repeated handling that causes acute stress. Gas bubble disease from supersaturated water causes bubbles to form in tissues, causing pain, buoyancy problems, and death in severe cases. As cod farming scales up, the welfare science needed to establish appropriate conditions for this specific species is still being developed, creating a risk that industry practice outpaces welfare knowledge.