Freshwater fish including carp, tilapia, and catfish constitute the majority of global aquaculture production. Their welfare needs are increasingly recognized as aquatic animal welfare science advances.
Freshwater fish welfare is often overshadowed by attention to higher-value marine species like salmon and sea bass, yet the sheer volume of freshwater fish production — over 50 million tonnes — means that welfare improvements in this sector affect more individual animals than any comparable intervention. Carp, the dominant species, show social learning, problem solving, and pain responses that support welfare consideration. Traditional pond polyculture systems — where multiple species are co-cultured at lower densities — allow more natural behavior than intensive monoculture. However, harvest welfare in pond systems is often poor, involving crowding, prolonged air exposure, and slaughter without stunning. Water quality management in intensive recirculating systems requires careful attention to ammonia, oxygen, and pH to prevent chronic stress. The Fish Welfare Initiative has begun developing welfare assessments specific to freshwater species. Consumer awareness of freshwater fish welfare lags significantly behind awareness of salmon and trout welfare.