Ocean sunfish, the world's heaviest bony fish, are caught as bycatch in Mediterranean and Atlantic fisheries, with welfare concerns about their handling and high discard mortality.
Ocean sunfish hauled aboard fishing vessels suffer traumatic injuries from the handling process including damage to their delicate skin, fins, and internal organs from the weight and pressure of landing. Animals returned to sea after significant handling have high discard mortality from injuries. Sunfish that survive initial capture and return may die from delayed injuries over days to weeks. The inability of fishing crews to handle such large, fragile fish safely makes bycatch interactions almost inevitably harmful for individual fish. Regulatory changes to reduce sunfish bycatch are preferable to improving handling given the near impossibility of safe return.