Coho salmon farmed in Chile and the Pacific Northwest face welfare challenges from sea lice, crowding, and disease in net pen aquaculture systems.
Coho salmon welfare in intensive net pen culture mirrors many of the challenges seen in Atlantic salmon production. Sea lice infestations cause welfare harm through skin lesions, gill damage, and energetic costs of dealing with parasites. Crowding stress is acute during handling operations including vaccine injection, grading, and lice treatment procedures. IHN and VHS viral diseases can cause high mortality with associated welfare impacts. Coho welfare assessment requires species-specific consideration as they have different behaviour and physiology to Atlantic salmon. Chile's rapid expansion of coho production has outpaced development of welfare standards, creating a regulatory gap that welfare advocates are working to address.