Salmon Farm Mortality: Scale, Causes and Reform

Mortality rates on salmon farms are among the most serious welfare indicators in aquaculture, with millions of fish dying before slaughter each year from sea lice, disease and handling stress.

Key Facts

Average salmon farm mortality rates in Norway are 14-20% — meaning 1 in 5-7 fish die before reaching slaughter weight
In 2022 over 60 million farmed salmon died in Norwegian farms before slaughter — more than the entire wild catch
Sea lice treatments are the leading cause of acute handling-related mortality events on farms
Jellyfish blooms, harmful algae and oxygen depletion cause mass mortality events affecting tens of millions of fish
The Salmon Welfare Index developed by Norway tracks mortality alongside other welfare indicators on individual farms

Welfare Considerations

The scale of mortality in salmon aquaculture is staggering and underappreciated by consumers. When 15-20% of all farmed salmon die before slaughter, each death represents a welfare failure — whether from sea lice damage, handling stress during treatments, disease, or environmental catastrophe. The fish that die are not simply inputs lost from a production system; they are sentient animals that experienced the conditions that killed them. Reducing mortality rates is simultaneously the most economically important and most welfare-important improvement available to salmon aquaculture, and the two objectives completely align.

What You Can Do

Choose salmon from farms or countries with independently verified low mortality rates
Ask retailers about mortality rate data from their salmon supply chains — this is a meaningful welfare metric
Support the Salmon Welfare Index approach to transparent, farm-level welfare reporting
Advocate for mandatory mortality reporting and publication for all salmon farms in your jurisdiction
Follow the Aquatic Life Institute for updates on salmon welfare standards that include mortality thresholds