Proposed deep-sea mining of mineral nodules would destroy some of the least understood ecosystems on Earth, raising profound welfare concerns for poorly known species.
Deep-sea mining poses welfare challenges at multiple levels. Known sentient species including fish, cephalopods and crustaceans inhabit proposed mining zones and would face habitat destruction and sediment suffocation. Many organisms in these ecosystems are entirely unstudied, raising questions about potential sentience in unknown taxa. The irreversibility of destruction in ecosystems with million-year recovery timescales makes the precautionary principle especially important. Welfare concerns for marine animals should be part of environmental impact assessments alongside biodiversity metrics.