Aquaculture Welfare

Salmon Welfare: Skeletal Deformities in Farmed Fish

Skeletal deformities including spinal curvature and jaw malformation are prevalent in some farmed salmon populations, causing chronic welfare problems and raising production concerns.

Key Facts

Skeletal deformities including vertebral compression and lordosis affect up to 20% of some farmed salmon cohorts
Nutritional deficiencies including vitamin C and phosphorus deficiency contribute to deformity development
High water temperatures during early development increase deformity rates
Deformed fish have impaired swimming ability, reduced competitiveness at feeding and higher mortality
Genetic selection and improved egg nutrition are reducing but not eliminating deformity rates

Welfare Considerations

Skeletal deformities cause chronic mechanical pain and impair normal swimming, feeding and social behaviour. Fish with severe deformities cannot compete effectively for feed and gradually deteriorate. Welfare-conscious aquaculture monitors deformity rates as a welfare indicator and invests in nutritional and genetic improvements to reduce prevalence. Deformed individuals should be humanely removed when identified.

What You Can Do

Support aquaculture welfare certification that includes deformity prevalence monitoring
Learn about the nutritional and environmental causes of salmon skeletal deformities
Advocate for welfare outcome metrics to be included in aquaculture standards
Choose salmon from operations with demonstrated low deformity rates