European sea bass is one of the most important farmed fish in the Mediterranean region. Intensive sea cage production raises significant welfare concerns around crowding, handling, and slaughter methods.
Sea bass welfare in Mediterranean aquaculture is shaped by both husbandry conditions and slaughter practices. At high cage densities, predatory species like sea bass show increased aggression, fin damage, and competition for feed that results in uneven growth distribution. Crowding also suppresses immune function, increasing disease susceptibility and antibiotic use. Handling during routine operations — net gathering, grading, transfer — causes acute stress and physical injury if not carefully managed. Slaughter welfare is highly variable: ice slurry immersion without prior stunning keeps fish conscious for several minutes while they experience thermal shock. CO2 narcosis, while sometimes used as an alternative, is aversive at effective concentrations. Percussive or electrical stunning before slaughter provides humane insensibilisation but requires capital investment that many Mediterranean producers have resisted. Certification schemes and EU welfare regulations are beginning to address slaughter, but implementation is uneven.