Salmon Aquaculture Disease Management and Fish Welfare

Disease outbreaks in salmon farms cause mass mortality and individual suffering, making health management central to aquaculture welfare improvement.

Key Facts

Infectious Salmon Anaemia, Pancreas Disease, and Amoebic Gill Disease cause major welfare and production losses
Sea lice infestations cause skin lesions, stress, and reduced feeding in affected Atlantic salmon
Cleaner fish including wrasse and lumpfish are used to control sea lice but face their own welfare challenges
Freshwater treatments and laser technology are increasingly used as non-chemical sea lice control options
Mortality rates in salmon farms can reach 15-20% over a production cycle from all causes combined
Recirculating Aquaculture Systems dramatically reduce pathogen exposure but require high capital investment
Water quality parameters including oxygen, temperature, and ammonia directly determine individual fish welfare
Crowding stress during treatment procedures increases disease susceptibility and injury risk

Welfare Considerations

Salmon disease management sits at the intersection of productivity and welfare in ways that are sometimes aligned and sometimes in tension. Disease reduces both welfare and economic returns, creating genuine incentive for farmers to invest in health. However, the treatments used to control disease can themselves cause welfare harm: crowding fish for bath treatments causes acute stress, mechanical lice removal causes tissue damage, and cleaner fish used as biological control agents face poor welfare outcomes in many operations. The welfare of individual fish during disease outbreaks involves both the direct effects of infection and the indirect effects of treatment, handling, and management stress. Integrated approaches that prevent disease through good biosecurity, water quality management, and reduced crowding offer the best welfare outcomes alongside production benefits.

What You Can Do

Support certification schemes that require disease monitoring and welfare-focused health management for aquaculture
Ask retailers about their salmon sourcing requirements for disease management and treatment welfare
Advocate for mandatory welfare standards for cleaner fish used in sea lice control
Support research into non-invasive disease monitoring and treatment methods for farmed fish
Reduce salmon consumption or choose land-based RAS salmon where available for better welfare outcomes