Sea lice infestations are the most significant welfare and economic challenge in Atlantic salmon farming, causing painful lesions and driving the use of treatments with their own welfare costs.
Sea lice represent a welfare challenge with no currently ideal solution. The lice themselves cause genuine suffering through tissue damage and physiological stress; the treatments used to remove them cause additional acute suffering through handling, temperature shock, or mechanical injury; and repeated treatment cycles create cumulative welfare costs across the production cycle. The welfare and economic case for prevention through better site management, reduced stocking densities, and monitoring technology is clear, but the industry has been slow to adopt preventive approaches systematically. Welfare-conscious consumers and certification bodies are increasingly factoring sea lice management practices into sourcing decisions, creating market incentives for higher-welfare integrated management.