Current Situation
Deep-sea fish species—including orange roughy, toothfish, grenadiers, and deep-water sharks—face welfare impacts from industrial bottom trawling and longlining. Orange roughy, which live over 100 years and are caught commercially, experience barotrauma (pressure-related injury) when brought to the surface from depths of 800-1,800 meters. These slow-reproducing fish are caught in deep-sea trawls that simultaneously destroy ancient cold-water coral ecosystems. Cephalopods in the deep sea include giant squid (Architeuthis dux), colossal squid (Mesonychoteuthis hamiltoni), and vampire squid (Vampyroteuthis infernalis). Giant squid are hunted by sperm whales in deep water, visible by sucker scars on whale bodies. These animals almost certainly have sophisticated nervous systems and plausibly experience pain, though they have never been observed alive in their natural deep-sea habitat. Deep-sea mining for polymetallic nodules (containing nickel, cobalt, manganese, and copper) is proposed for the Clarion-Clipperton Zone of the Pacific and other areas. Nodule fields, which take millions of years to form, support diverse fauna including sea cucumbers, brittle stars, polychaete worms, and sponges. Mining operations would destroy these communities entirely. The International Seabed Authority is developing mining regulations, but animal welfare of deep-sea invertebrate communities is rarely addressed in environmental impact assessments. Hydrothermal vent communities support unique fauna adapted to extreme heat, pressure, and chemical conditions. Tube worms, vent crabs, and vent shrimp live in one of Earth's most extreme environments. Welfare of vent organisms is virtually unstudied but relevant given growing scientific and commercial interest in these ecosystems.
Key Welfare Issues
Animal welfare in extreme and remote environments reflects the intersection of natural ecology, human activities, and scientific uncertainty. Evidence-based approaches require both empirical research and careful consideration of what welfare means for species with very different nervous systems and ecological contexts.
Pathways Forward
Progress requires investment in welfare science for understudied taxa, protection of remote and extreme habitats, climate change mitigation, and international cooperation through frameworks like the Antarctic Treaty and Arctic Council.
Further Reading
Resources from the World Organisation for Animal Health, Wild Animal Initiative, and polar research institutions provide evidence-based guidance.