As aquaculture becomes increasingly central to global protein supply, the welfare challenges of farming fish and invertebrates at massive scale require systematic solutions that the industry is only beginning to address.
The scale of aquaculture means that even marginal improvements in fish welfare practices have enormous aggregate impact — millions or billions of fish are affected by individual farm decisions. Yet the industry operates with minimal welfare oversight compared to terrestrial livestock, reflecting historical assumptions about fish sentience that science has increasingly challenged. Fish pain research now provides substantial evidence that fish experience aversive states that are welfare-relevant, though the exact nature of their subjective experience remains debated. Key welfare challenges in aquaculture at scale include crowding stress, disease management without adequate veterinary oversight, slaughter methods of uncertain humaneness, and the inability to monitor individual animals in large populations. Industry-wide welfare improvement requires both scientific investment in welfare indicators and regulatory frameworks that create accountability for welfare outcomes.