Fish cognitive complexity is increasingly recognised by scientists. Providing cognitive enrichment in aquaculture — stimulation that engages problem-solving and learning — is an emerging welfare frontier.
The welfare case for cognitive enrichment in farmed fish rests on the same foundation as enrichment for mammals and birds: animals with complex nervous systems experience suffering when confined to barren, monotonous environments. Fish show learning, memory, preference, and aversion behaviours that demonstrate the capacity for experiences beyond simple reflexes. Recirculating aquaculture systems, while offering advantages in water management and disease control, often provide minimal environmental variation. Introducing variable current patterns, shelter objects, and feeding challenges that require simple problem-solving has been shown to reduce stress hormones, aggression, and abnormal swimming patterns. The field is young, but the evidence base is sufficient to justify investment in fish enrichment as a mainstream welfare priority for the aquaculture industry.