Some tuna RFMOs have adopted regulations that aim to halt the practice of shark finning, in which sharks are landed onboard and their high value fins removed. Sharks will be caught regardless of whether they are target or non-target species, and the commercial incentives for shark finning encourage over-exploitation of shark species. Sharks that are landed and finned will die and their carcasses are discarded at sea. Furthermore, it is very difficult to identify sharks by species unless fins are attached to carcasses, which has implications for data collection and thus bycatch management.
Shark finning restrictions include regulatory requirements such as the use of fin-to-carcass-weight ratios, 'full retention', i.e., prohibition of removal of shark fins at sea, or similarly, that all sharks be landed with their fins naturally attached (fully or partially). Regulations may prohibit fishing vessels from retaining on board, transshipping, landing, or trading any fins harvested in contravention of a regulation.