Atlantic salmon in aquaculture pens lack the environmental complexity of wild rivers, and enrichment research is exploring whether providing structures and flow can improve welfare.
The welfare of farmed salmon is increasingly recognised as a significant issue given the species being produced — animals that in the wild undertake remarkable migratory journeys through structurally complex environments. Commercial pens provide a static, featureless environment that requires salmon to swim in circles with minimal stimulation. Research into enrichment options including submersible structures, varied lighting, and adjustable current flow suggests that even modest complexity improvements can reduce aggression, improve swimming behaviour, and reduce stress indicators. These findings are beginning to influence commercial practice in leading salmon farming nations.