European sea bass is one of the most commercially important farmed fish species in the Mediterranean, but welfare challenges including crowding stress, handling injuries, and painful slaughter methods require urgent attention.
Farmed sea bass experience chronic stress from high stocking densities that prevent normal territorial behaviour and force constant proximity to conspecifics. Crowding stress suppresses immune function, increasing disease susceptibility and requiring more medication use. Handling during grading, transport, and harvesting causes acute stress responses measurable in cortisol and behaviour. CO2 stunning — the predominant slaughter method — causes a prolonged aversive period before insensibility rather than instant stunning. Research into fish welfare in sea bass aquaculture has advanced substantially, with clear evidence of sentience and stress capacity. Adoption of more humane slaughter methods and reduced stocking densities represents achievable improvements with current technology.