The humaneness of fish slaughter varies enormously across species and production systems. Pre-slaughter stunning renders fish unconscious before killing, preventing the pain and stress of conscious slaughter. Standards and adoption remain inconsistent.
The welfare stakes of fish slaughter are significant — if fish experience pain and distress (as growing evidence suggests), then killing millions of fish using methods that allow prolonged consciousness represents an enormous welfare problem. The precautionary principle suggests that pre-slaughter stunning should be standard practice even while scientific certainty about fish sentience develops. The practical and economic barriers to pre-slaughter stunning have diminished as effective technologies become more widely available and affordable. Consumer preference for certified products is one of the primary levers driving adoption of better slaughter practices.