Salmon welfare in aquaculture is assessed through behavioral indicators including swimming patterns, surface activity, and escape behavior that reflect underlying health and stress.
Salmon welfare assessment has advanced significantly from purely health-based measures to include behavioral and mental state indicators. Fish showing abnormal swimming patterns, surface breaking, or reduced shoaling cohesion signal welfare deficits that precede detectable disease. The Norwegian operational welfare indicator framework provides a model that other countries are adopting - requiring farms to monitor and respond to behavioral welfare signals in addition to mortality and disease metrics. This shift toward proactive behavioral monitoring reduces suffering duration.