Shrimp are typically killed by immersion in ice slurry - evidence of nociception raises welfare concerns, and more humane methods are under investigation.
Shrimp slaughter welfare sits at the frontier of what we consider to matter morally. The evidence that shrimp have nociceptors and protective pain responses has grown sufficiently to warrant welfare consideration under the precautionary principle. The practical challenge is that existing slaughter infrastructure is designed for speed and volume, not welfare. Research into more humane slaughter methods - rapid chilling, electrical stunning, or chemical methods - is advancing. Consumer and regulatory pressure for welfare improvements at slaughter is an important driver of this research.