Advances in fish stunning technology including electrical, percussive, and carbon dioxide systems are providing more humane slaughter options for farmed fish at commercial scale.
Fish stunning technology has advanced significantly in recent years, moving from theoretical possibility to commercial application for at least some farmed species. For salmon and large trout, properly calibrated electrical stunning provides immediate insensibility that represents a genuine welfare advance over CO2 immersion or asphyxiation. The challenge is extending these advances to smaller species, different species, and the full scale of global aquaculture production. Automated systems that can process large numbers of fish humanely are commercially available and economically viable at scale. The barrier to widespread adoption is primarily regulatory — absent requirements for humane slaughter, producers have little economic incentive to invest in better technology.