Aquaculture

Aquaculture: Sea Lice Treatment Welfare Salmon

Sea lice treatments in salmon farming include chemical and non-chemical approaches, each with distinct welfare implications for treated fish.

Key Facts

Sea lice are ectoparasites causing significant welfare harm to farmed salmon
Chemical treatments include azamethiphos, hydrogen peroxide and deltamethrin bath treatments
Non-chemical treatments include warm water (Thermolicer) and freshwater (Hydrolicer) machines
Mechanical treatment involves fish being pumped and tumbled which causes injury
Treatment welfare must balance lice harm against treatment harm

Welfare Considerations

Both sea lice infestation and treatment cause welfare harm to salmon. Chemical bath treatments cause acute stress from crowding and chemical exposure. Mechanical treatments cause physical injury. No current treatment is welfare-neutral. The optimal welfare choice balances lice burden reduction against treatment impact.

What You Can Do

Support research into gentler sea lice treatment methods
Choose certified salmon from operations with integrated lice management
Advocate for welfare assessment of treatment methods in aquaculture regulations
Support development of biological controls as lower-welfare-impact alternatives