Aquaculture

Farmed Salmon Mucus Barrier Welfare

The mucus barrier on salmon skin provides immunity and protection, with welfare implications when it is damaged by lice, treatment, or handling.

Key Facts

Atlantic salmon skin mucus contains antibodies, antimicrobial peptides, and lectins
Sea lice feeding on mucus causes skin lesions exposing underlying tissue
Chemical lice treatments can cause mucus loss and skin irritation if incorrectly applied
Handling and crowding stress reduces mucus production and immune function
Mucus integrity is a welfare indicator reflecting the cumulative stress burden on fish

Welfare Considerations

Mucus barrier integrity is a welfare indicator reflecting the cumulative stress and health status of individual salmon. Damaged mucus exposes fish to infection and indicates welfare compromise from lice infestation, treatment, or handling. Maintaining mucus integrity through minimising stress events and appropriate lice management is a holistic welfare approach.

What You Can Do

Support certified salmon farms with integrated lice management minimising treatment
Choose salmon from farms with transparent welfare monitoring including skin health
Advocate for mucus integrity assessment as a welfare performance indicator