Disease in Farmed Fish: Welfare, Economics, and Prevention

Disease is the leading welfare and economic challenge in aquaculture, causing mass mortality and chronic suffering across salmon, trout, tilapia, and other farmed fish species.

Key Facts

Infectious Pancreatic Necrosis (IPN) causes mass mortality in Atlantic salmon farms
Bacterial kidney disease causes chronic progressive disease and significant welfare harm in salmonids
Tilapia lake virus (TiLV) has spread to five continents since its identification in 2016
Biosecurity measures including closed containment and selective breeding for disease resistance reduce disease pressure
Vaccines have replaced antibiotics for several major salmon diseases in Norway — a major welfare improvement

Welfare Considerations

Disease in aquaculture causes widespread suffering. Fish with bacterial infections experience chronic pain and progressive physiological deterioration. Parasitic diseases including sea lice and whirling disease cause tissue damage and behavioral impairment. Mass mortality events — in which thousands or millions of fish die within days — involve acute suffering at scale. Disease prevention through biosecurity, vaccination, and genetic improvement is both economically valuable and welfare-improving. The welfare and economic cases for disease prevention are aligned, making it an area where commercial and welfare interests converge.

What You Can Do

Choose aquaculture products from operations with documented disease management and biosecurity standards
Support research into fish vaccines as an antibiotic-free disease management approach
Advocate for mandatory disease reporting requirements in aquaculture licensing
Reduce consumption of farmed fish species with particularly poor disease management records
Engage with aquaculture certification schemes that include disease welfare criteria in their standards