Welfare considerations for farmed Arctic char — a cold-water salmonid with specific thermal and social needs.
Arctic char welfare in aquaculture is fundamentally dependent on temperature management. As a cold-water species, char experience significant stress when temperatures rise above their thermal optimum. Chronic exposure to elevated temperatures suppresses immunity, reduces appetite, impairs growth, and increases disease susceptibility. Climate change is making temperature management increasingly challenging at lower-latitude farms.
Social behaviour is a critical welfare consideration in char farming. Arctic char form dominance hierarchies and show size-based aggression that can lead to fin damage, injury, and uneven resource access. High stocking densities reduce the ability to maintain normal social spacing and exacerbate competitive interactions. Welfare-oriented stocking densities and regular size grading to maintain group homogeneity improve social welfare outcomes.
Water quality management — particularly oxygen levels, which decrease as temperatures rise — is critical. Char require high oxygen levels and are sensitive to ammonia accumulation. Regular water quality monitoring and appropriate system management are essential welfare prerequisites.