In-depth welfare assessment of farmed European sea bass — a premium species with complex welfare needs.
European sea bass welfare in aquaculture is affected by the intensive nature of Mediterranean cage and tank culture. High stocking densities in sea cages restrict natural swimming patterns and increase competition for resources. Aggressive interactions cause fin damage, scale loss, and eye injuries that serve as measurable welfare indicators. The presence of fin damage and eye injuries in cage populations indicates chronic social stress and competition.
Handling during routine husbandry — grading, vaccination, treatment — causes acute stress responses. Sea bass are particularly sensitive, showing pronounced cortisol elevation and immune suppression following capture and handling. Anaesthesia protocols for procedures reduce but do not eliminate stress responses. The recovery environment post-handling is critical to welfare outcomes.
Sea lice infestations (primarily Sparicotyle chrysophrii in sea bass) cause chronic irritation, skin damage, and welfare impairment. Treatment with hydrogen peroxide bath treatments causes acute stress and requires careful welfare management to avoid secondary mortality.