Stocking density management in gilthead seabream farms is critical to welfare, with chronic crowding causing stress, injury, and immune suppression.
Chronic crowding in seabream sea cages causes persistent cortisol elevation, reduced immune competence, and increased disease susceptibility. Fin damage from aggressive interactions at high density causes wounds that become infection routes. Individual fish within a population show variable stress susceptibility, creating welfare disparities within cohorts. Welfare-conscious seabream farming manages density to maintain individual fish below chronic stress thresholds, accepting reduced biomass per unit as a welfare investment. Certification schemes specifying maximum stocking density are the key policy lever.