Yellowtail are highly active pelagic fish farmed primarily in Japan for sashimi markets. Their welfare requirements — extensive swimming space and high-quality water — are difficult to meet in intensive cage systems.
Yellowtail welfare in aquaculture is significantly constrained by their biology as high-energy pelagic predators. These fish are built for continuous swimming and high oxygen consumption — conditions that cage systems fundamentally cannot replicate. Chronic exercise restriction in fish evolved for extensive daily movement likely causes significant welfare cost. Stress in yellowtail is associated with elevated parasite burden, reduced growth, and increased aggression — all of which are measurable welfare and production indicators. Welfare improvements focus on optimising water quality including dissolved oxygen, minimising handling frequency, providing adequate cage volume per fish, and using low-stress harvest and transport techniques. The species' welfare requirements argue for significant space per animal, creating an inherent tension with intensive production economics.