Aquaculture

Farmed Salmon Hatchery Deformity Welfare

Hatchery management critically determines deformity rates in farmed salmon, with prevention during sensitive developmental windows most effective.

Key Facts

Spinal deformities occur during the alevin stage when vertebral development is most sensitive
Elevated temperatures and inadequate vitamin nutrition during this stage increase deformity rates
Deformity rates have been reduced from over 20 percent to under 5 percent through hatchery improvements
Radiographic screening at smolt stage allows deformity prevalence monitoring without harvest
Fish with severe deformities should be culled humanely rather than entered into production

Welfare Considerations

Salmon with spinal and jaw deformities suffer from chronic postural discomfort and feeding impairment throughout their lives. Prevention through hatchery management during the alevin stage eliminates this lifelong welfare cost before it occurs.

What You Can Do

Support certification schemes that require deformity monitoring and reporting at hatchery stage
Advocate for mandatory deformity rate reporting in salmon hatchery licensing applications
Choose salmon from farms with vertically integrated welfare standards from egg to harvest