Coho Salmon Welfare in Pacific Aquaculture
Coho salmon farmed in Chile, Canada, and the US face welfare challenges including sea lice, crowding, and inhumane slaughter that deserve urgent attention.
Key Facts
- Coho salmon is farmed primarily in Chile, Canada, and the US in marine net-pen systems
- Sea lice infestation causes chronic welfare harm through skin damage and pain-like behavior
- Coho are more aggressive than Atlantic salmon, increasing intraspecific injury risk at high densities
- Pre-harvest crowding for harvest operations causes acute stress and physiological compromise
- Electric stunning before slaughter is increasingly adopted but remains inconsistent across operations
Welfare Considerations
Coho salmon welfare deserves specific attention alongside Atlantic salmon given its growing production scale and specific welfare vulnerabilities. Coho are more territorial and aggressive than Atlantic salmon, meaning that crowding-related aggression causes higher rates of fin damage and scale loss at equivalent stocking densities. Sea lice management through chemical treatments involves handling stress that itself constitutes a welfare harm. The welfare of coho during harvest — crowding, aerial exposure during brailing, and slaughter — remains inconsistent, with stunning adoption rates lower than for Atlantic salmon in some markets. Welfare improvements including species-specific stocking density limits, reduced handling frequency for sea lice management, and mandatory stunning before slaughter would significantly improve coho welfare outcomes.
What You Can Do
- Choose coho salmon from certified operations that require stunning before slaughter
- Support species-specific welfare standards for coho salmon in aquaculture certification programs
- Advocate for sea lice treatment methods that minimize handling stress for coho
- Engage retailers and food service companies to ask about coho salmon welfare standards
- Support research into coho-specific behavioral welfare indicators and optimal stocking densities