NMFS issues this final rule to implement fishery conservation and management measures for the U.S. purse seine fishery in the eastern Pacific Ocean (EPO) to reduce bycatch of juvenile tuna, non-target fish species, and non-fish species. These measures were recommended by the Inter-American Tropical Tuna Commission (IATTC) and approved by the U.S. Department of State (DOS), in accordance with the Tuna Conventions Act of 1950. In addition, this rule establishes reporting requirements for U.S. vessels fishing for tuna in the EPO in order to gather information that NMFS can provide to the IATTC for a regional vessel register. The vessel register will promote consistent compliance across all IATTC member nations by ensuring constant attention to fleets active in the area and aiding in identification of vessels engaged in illegal, unreported or undocumented fishing in the EPO.