Aquaculture

Farmed Salmon Disease Management: ISA, Amoeba and Welfare

Infectious diseases including ISA and amoebic gill disease cause significant suffering in farmed salmon and drive widespread medication use. Understanding disease welfare impacts matters.

Key Facts

Infectious salmon anaemia (ISA) causes haemorrhagic disease and high mortality
Amoebic gill disease (AGD) impairs gas exchange causing respiratory distress
Disease events drive emergency treatments with welfare costs for treated fish
Norway experienced multiple ISA outbreaks requiring mass culls in the 2000s
Fallowing and improved biosecurity have reduced ISA incidence significantly
Early disease detection through gill scoring and monitoring reduces disease duration

Welfare Considerations

Disease-affected salmon suffer from physiological distress, impaired breathing, reduced feeding, and chronic immune activation. Mass mortality events kill fish through severe physiological failure. Emergency treatments including freshwater bathing for AGD cause handling stress that compounds with the disease burden. Prevention through biosecurity, fallowing, and monitoring is both the economically and welfare-optimal strategy.

What You Can Do

Choose salmon from farms with documented disease management and low treatment rates
Support research into disease-resistant salmon genetics without compromising welfare
Advocate for mandatory disease monitoring and reporting in all aquaculture licensing