Deep-sea cephalopods including giant squid and dumbo octopus are among the least understood animals on Earth, yet face growing threats from deep-sea fishing and raise profound welfare questions.
Deepwater cephalopod welfare exists at the very frontier of welfare science. The combination of high neural complexity, demonstrated learning and problem-solving abilities, and probable pain processing in shallow-water relatives creates a strong precautionary case for concern. Deep-sea species face unique welfare challenges: capture typically involves fatal decompression barotrauma, and virtually no research has examined their stress responses or welfare needs. The expansion of deep-sea mining and fishing into previously undisturbed habitats will affect these animals in ways that are almost entirely uncharacterised. The precautionary principle strongly supports moratorium on deep-sea trawling in high-biodiversity zones.