NMFS amends the regulations governing the Atlantic tuna fisheries to set Atlantic bluefin tuna (ABT) fishing category quotas for the 1997 fishing year. The regulatory amendments are necessary to implement the 1996 recommendation of the International Commission for the Conservation of Atlantic Tunas (ICCAT) regarding fishing quotas for bluefin tuna, as required by the Atlantic Tunas Convention Act (ATCA), and to achieve domestic management objectives.