Gilthead sea bream (Sparus aurata) is one of the most important farmed fish species in the Mediterranean, with annual production exceeding 250,000 tonnes. Despite its commercial significance, welfare science for this species lags behind salmonid research.
Sea bream in Mediterranean net cages face chronic crowding stress, with stocking densities often exceeding welfare thresholds. Cataract formation, a preventable nutritional welfare problem, compromises vision and feeding ability in affected fish. Aggressive interactions at high densities cause fin and scale damage. Pre-slaughter crowding in holding nets causes acute stress and physical injury; welfare-improving alternatives include reduced-crowding transfer and carbon dioxide or percussive stunning before slaughter. The absence of fish welfare regulations in Turkish and Greek aquaculture — the largest producers — means market pressure is the primary lever for welfare improvement.