Oarfish are the world's longest bony fish, rarely seen alive, and their welfare in any context — from strandings to bycatch — deserves consideration.
Stranded oarfish present acute welfare concerns. Their deep-water physiology makes them physiologically compromised at the surface, and beach strandings are typically terminal events. Attempts to return stranded oarfish to the sea are rarely successful. The primary welfare concern beyond strandings is bycatch in deep-set longline and trawl fisheries. Little is known about their pain experience or stress response due to the rarity of encounters. Any attempts to capture or restrain oarfish for observation cause significant physiological stress given their deep-sea adaptations.