Farm Animals

Farmed Salmon Sea Lice Welfare

Sea lice infestations are the most significant welfare challenge in farmed salmon; prevention and treatment approaches vary greatly in welfare impact.

Key Facts

Sea lice cause skin lesions, stress, and secondary infection in farmed salmon
Global sea lice costs to the salmon industry exceed $1 billion annually
Cleaner fish including wrasse and lumpfish control lice but have their own welfare needs
Hydrogen peroxide and warm water treatments cause acute stress
Snorkel cages and submerged lighting reduce lice attachment by limiting surface exposure

Welfare Considerations

Sea lice cause progressive tissue damage that exposes underlying flesh, causes immune suppression, and predisposes to secondary disease. Heavily infested fish experience chronic pain and stress that severely impairs welfare. Treatment approaches vary enormously in welfare impact - from physical preventive systems with low welfare cost to chemical treatments causing acute distress. Progressive farms prioritise prevention over treatment.

What You Can Do

Choose salmon from farms with low sea lice counts and preventive management
Ask retailers about sea lice management practices in their salmon supply chains
Support certification schemes including sea lice welfare thresholds
Advocate for industry-wide sea lice reporting and welfare standards
Support research into non-chemical sea lice prevention technologies