Aquaculture

Farmed Salmon Lice Treatment Welfare: Thermolicer and Hydrolicer

Mechanical lice treatment using warm water (thermolicer) and freshwater (hydrolicer) causes acute welfare impacts in treated salmon.

Key Facts

Thermolicer exposes salmon to 34-degree water briefly to kill lice - causes thermal shock
Post-treatment mortality from mechanical lice removal can reach 1-5% of treated fish
Hydrolicer uses freshwater immersion causing osmotic stress in marine-adapted salmon
Combining mechanical treatment with biological control reduces treatment frequency needed

Welfare Considerations

Each mechanical lice treatment causes acute stress and mortality. Reducing treatment frequency through biological control and water quality management is both economically and welfare beneficial. Treatment mortality is an underreported welfare cost in salmon farming.

What You Can Do

Support certification standards requiring minimisation of mechanical lice treatments
Advocate for mandatory treatment mortality reporting in salmon aquaculture
Choose salmon from farms with published lice management and treatment welfare data