Coho Salmon Aquaculture Welfare | Animal Welfare Hub

Coho salmon aquaculture is expanding in Chile and North America. Welfare challenges overlap with Atlantic salmon but include species-specific behavioral needs and sensitivity to crowding stress.

Key Facts

Coho salmon (Oncorhynchus kisutch) production is concentrated in Chile, with growing operations in North America and Japan
Coho are naturally territorial and show high aggression in confined conditions, leading to fin damage and wound accumulation
They have a shorter production cycle than Atlantic salmon — typically 18-24 months to market weight
Coho demonstrate clear stress responses to handling, overcrowding, and poor water quality
Pre-slaughter stunning practices for coho salmon vary by producer — electrical and percussive methods are available
Wild coho salmon populations are severely depleted in much of their North American range, making aquaculture expansion controversial

Welfare Considerations

Coho salmon welfare in aquaculture shares fundamental challenges with other salmonid species. Their territorial nature in confined sea cages creates chronic aggression that causes fin erosion, scale loss, and wound accumulation — direct welfare indicators that are measurable and have been used to assess welfare status in research contexts. Stocking density management is the primary lever for reducing aggression-related welfare harm. Water temperature and oxygen management are critical — coho are cold-water specialists that experience stress and immune compromise when temperatures exceed optimal ranges. Sea lice, while less problematic in coho than Atlantic salmon in some regions, remain a welfare concern in sea cage systems. The pre-slaughter welfare of coho varies considerably by producer — some Chilean operations use electrical stunning while others rely on ice slurry or CO2 exposure. Given the welfare science consensus on fish pain capacity, standardizing pre-slaughter stunning across coho production represents a high-priority improvement opportunity with available technical solutions.

What You Can Do

Choose coho salmon products from ASC-certified producers with documented welfare standards including pre-slaughter stunning
Advocate for mandatory stunning requirements for salmonid species across all major producing countries
Support research into coho-specific density thresholds that balance welfare and production efficiency
Reduce overall farmed salmon consumption and prioritize welfare-certified alternatives when purchasing
Support wild coho salmon habitat restoration as a complement to responsible aquaculture development