Farmed Salmon: Disease Management and Fish Welfare

Disease outbreaks in salmon farming cause mass mortality events and extensive suffering, requiring integrated prevention strategies that consider welfare alongside production outcomes.

Key Facts

Infectious Salmon Anaemia (ISA) can kill entire farm cohorts and leads to emergency slaughter
Amoebic gill disease (AGD) causes respiratory compromise and requires treatment with freshwater baths
Bacterial diseases including furunculosis and vibriosis cause significant mortality in poorly managed farms
Vaccination programmes substantially reduce bacterial disease but cannot prevent all pathogens
Fallowing - resting sea sites between production cycles - reduces pathogen loads

Welfare Considerations

Disease events in salmon farming cause suffering through acute illness, chronic debilitation and emergency slaughter under poor conditions. Prevention through robust biosecurity, vaccination, fallowing and reduced stocking density is the welfare-optimal approach. Treatment decisions must weigh the welfare of diseased fish against treatment stress. Emergency depopulation of severely affected cohorts may be the most welfare-protective decision when disease cannot be controlled.

What You Can Do

Support aquaculture certification schemes with robust disease management standards
Learn about the ecology of salmon diseases and their drivers
Advocate for fallowing requirements to be maintained in aquaculture regulation
Choose salmon with certification schemes that include disease management welfare provisions