Farmed Salmon Wellbeing Indicators: Eye Damage, Wounds, and Behaviour

Specific welfare indicators in farmed Atlantic salmon allow systematic assessment of individual and population welfare. Understanding these indicators informs better farm management.

Key Facts

Eye damage and cataracts are common in farmed salmon and associated with poor nutrition and stress
Wound prevalence from scale loss and fin damage indicates crowding stress and aggressive interactions
Operculum score — condition of the gill cover — is a validated welfare indicator
Swimming speed and schooling behaviour provide real-time welfare status information
Mortality rate and culled fish percentage are basic but important welfare outcome measures

Welfare Considerations

Welfare assessment in farmed Atlantic salmon uses specific animal-based indicators to provide objective, comparable welfare data. Eye damage including cataracts indicates nutritional deficiency and chronic stress. Wound scores from scale loss, fin damage, and skin lesions reflect crowding stress and aggressive interactions. Operculum damage indicates gill health. These indicators can be assessed through periodic sampling of individuals from cages, providing data that tracks welfare over time and enables comparison between farms and management approaches. Regular welfare assessment using validated indicators — rather than relying solely on production data like mortality rates — enables proactive management to address emerging welfare problems before they become severe.

What You Can Do

Support aquaculture certification that requires regular welfare assessment using validated indicators
Choose farmed salmon from operations that publish welfare assessment data
Advocate for mandatory welfare outcome reporting requirements in aquaculture regulation
Learn about salmon welfare indicators to better evaluate aquaculture welfare claims