European sea bass (Dicentrarchus labrax) is one of the most commercially important Mediterranean farmed fish, facing welfare challenges from density, handling, and slaughter.
Sea bass welfare science has advanced considerably, with clear evidence these fish experience stress, fear, and pain-like states. In intensive aquaculture, chronic crowding activates sustained stress responses that impair immunity and growth. Handling during grading and transfer procedures triggers acute stress responses with measurable physiological markers. Slaughter by asphyxiation — leaving fish to die slowly in air — is particularly problematic: sea bass remain conscious and stressed for many minutes. Emerging research on percussive stunning and CO2 exposure indicates that current commercial practice is among the poorest methods available for reducing suffering at slaughter.