Deep sea fishing operations targeting species including orange roughy, toothfish, and deep sea sharks involve welfare concerns both for target species and for the diverse array of bycatch brought up from hundreds of meters depth.
Deep sea fishing welfare involves multiple compounding harms. Target species may have experienced decades of life before capture. Barotrauma from rapid decompression causes internal injuries including swim bladder expansion, gas bubble formation in tissues, and exophthalmia (eye protrusion) - painful conditions that may persist in released animals that survive the haul. Bycatch mortality includes cold-water coral communities that may be hundreds to thousands of years old. Welfare-positive deep sea fisheries management reduces bycatch through gear modification, area closures, and species-specific catch limits. Consumer demand for certified sustainable deep sea species creates market pressure for better practices.