Sea urchins are increasingly farmed for their prized roe, raising novel questions about invertebrate sentience and welfare in aquaculture systems.
The question of whether sea urchins can suffer is genuinely uncertain. Their decentralised nervous system differs fundamentally from vertebrate architectures, and their defensive responses to noxious stimuli could be reflexive rather than involving subjective experience. The precautionary principle suggests that where sentience is uncertain, we should minimise potential suffering — including in handling, slaughter and environmental conditions. As aquaculture expands into new invertebrate species, developing welfare frameworks that acknowledge uncertainty while providing practical guidance is essential to ensure that scale-up does not cause harm we later recognise as serious.