Welfare considerations for farmed yellowtail (Seriola species) in Japanese and emerging aquaculture systems, covering their schooling behavior, disease management, and slaughter practices.
Yellowtail aquaculture welfare is an area of significant concern that has received less international attention than salmon welfare, despite the large volumes produced and the substantial welfare issues present. As pelagic schooling fish adapted for vast open-ocean movement, yellowtail experience profound confinement in even the largest commercial net-pen operations — their natural behavioral repertoire includes synchronized schooling over kilometers, which cannot occur in any captive setting. High stocking densities create chronic competition for space and feeding position, with dominant individuals excluding subordinates from optimal feeding access. Disease management in intensive yellowtail production requires frequent handling for treatment and sorting — each handling event causes acute stress. Most critically, slaughter practices for yellowtail are predominantly non-stunning: live bleeding without prior unconsciousness is the common method, causing prolonged cardiovascular and neurological distress before death. The traditional Japanese ikejime technique provides immediate destruction of the brain followed by spinal severance, eliminating conscious suffering at slaughter and additionally improving flesh quality — a compelling alignment of welfare and commercial interests.