Fish slaughter methods in aquaculture vary enormously in welfare outcomes. Electrical stunning and percussive stunning are available but adoption lags behind what welfare science supports.
Fish slaughter welfare represents one of the most tractable welfare improvements available in aquaculture - the technology for humane slaughter exists and is commercially deployed at scale in leading markets. The contrast between best-practice stunning that renders fish insensible in under a second, and the baseline practice of 15-60 minutes of conscious asphyxiation in ice slurry, represents an enormous and easily measurable welfare gap. Norway's mandatory stunning requirement demonstrates regulatory action is feasible. Consumer certification schemes that require effective stunning create market incentives for adoption. The barrier is primarily economic and cultural rather than technical.