Providing environmental complexity for farmed Atlantic salmon is an emerging welfare strategy with promising evidence for reducing stress and improving fish welfare indicators.
Salmon evolved in complex river environments with current, shelter, variable light, and foraging challenges. Sea cage culture typically provides highly uniform environments that prevent natural habitat use. Enrichment approaches that add environmental complexity show measurable welfare benefits including reduced cortisol, less fin damage, and improved growth. The challenge is developing enrichment approaches that are practical at commercial scale in sea cage conditions.