Japanese yellowtail (hamachi) is one of the most important marine aquaculture species in Japan, with welfare challenges around stocking density, disease management, and pre-slaughter handling.
Japanese yellowtail welfare in sea cage systems is challenged by the mismatch between the species natural high-energy swimming behaviour and the constraints of cage confinement. Crowding during routine husbandry and pre-harvest reduces water oxygen levels, causing acute respiratory stress. Pre-slaughter confinement and net-crowding causes severe physiological stress with demonstrable welfare impacts on flesh quality. Ikejime (brain spiking) is a traditional Japanese slaughter method that causes rapid death and is the most welfare-positive approach available for this species at commercial scale.