Sets forth provisions regarding: (1) civil and criminal penalties; (2) search, inspection, shipment detention, arrest, and subpoena authorities; and (3) prohibited actions.

Amends the High Seas Driftnet Fishing Moratorium Protection Act to direct the Secretary to identify nations or certain entities that are engaged or have been engaged during the preceding three years in illegal or unregulated fishing, or that have violated related conservation and management measures.

Prohibits certain activities under specified fishing and marine Acts, including: (1) refusing, resisting, or interfering with searches, investigations, inspections, or observers; (2) importing, exporting, transporting, selling, or purchasing fish or fish products in violation of a treaty or any binding conservation measure to which the United States is a party; or (3) falsifying records, accounts, labels, or product identification.

Authorizes the Secretary to: (1) identify vessels and vessel owners engaged in illegal or unregulated fishing; and (2) take appropriate action against such vessels and vessel owners in accordance with U.S. and international law. Applies any action restricting port privileges to all U.S. and territorial ports.

Directs the Secretary to establish an International Fisheries Enforcement Program in the Office of Law Enforcement of the National Marine Fisheries Service to investigate illegal or unregulated fishing activity and enforce the provisions of this Act.

Authorizes the Secretary to establish an international cooperation and assistance program to provide assistance for international capacity building efforts.

Authorizes information disclosure to the U.N. Food and Agriculture Organization, international fishery management organizations, or arrangements made under an international fishery agreement, if those organizations or arrangements have unauthorized information disclosure safeguards.

Amends the High Seas Fishing Compliance Act to revise high seas fishing permit provisions.

Antigua Convention Implementing Act of 2011 - Amends the Tuna Conventions Act of 1950 to revise provisions regarding: (1) the Inter-American Tropical Tuna Commission; (2) the General Advisory Committee; (3) the Scientific Advisory Subcommittee; (4) prohibited acts; and (5) enforcement.

Repeals the Eastern Pacific Tuna Licensing Act of 1984.

International Fisheries Stewardship and Enforcement Act - Title I: Administration and Enforcement of Certain Fishery and Related Statutes - (Sec. 101) Directs the Secretary of Commerce (the Secretary) and the Secretary of the department in which the Coast Guard is operating to enforce specified laws concerning fisheries and fish products, including the High Seas Driftnet Fishing Moratorium Protection Act, the Pacific Salmon Treaty Act of 1985, the Dolphin Protection Consumer Information Act, the Atlantic Tunas Convention Act of 1975, the Northern Pacific Halibut Act of 1982, and any other similar law designated by the Secretary.

Provides for enforcement as though specified prohibited acts and enforcement provisions of the Magnuson-Stevens Fishery Conservation and Management Act had been incorporated into each of those Acts. Sets civil and criminal penalties (including criminal forfeiture) for violations and sets forth search, inspection, shipment detention, arrest, and subpoena authorities.

Makes certain acts unlawful, including regarding: (1) refusing, resisting, or interfering with searches, investigations, inspections, or observers; (2) importing, exporting, transporting, selling, or purchasing fish or fish products in violation of a treaty or any binding conservation measure to which the United States is a party; or (3) falsifying records, accounts, labels, or product identification.

(Sec. 102) Amends the High Seas Driftnet Fishing Moratorium Protection Act to direct the Secretary to identify nations or certain entities that are engaged or have been engaged during the preceding three years in illegal or unregulated fishing, or that have violated related conservation and management measures. (Current law requires an identification of nations so engaged during the preceding two years.) Applies such Act to any other entity that is competent to enter into an international fishery management agreement.

Requires the Secretary's biennial report to Congress on international compliance to identify a nation if fishing vessels of that nation are engaged, or have been engaged during the preceding three years in fishing activities or practices in certain waters beyond the national jurisdiction or exclusive U.S. economic zone that result in certain bycatch of protected living marine resource. (Current law requires an identification of nations so engaged during the preceding calendar year.)

Makes it unlawful for any person to make or submit any false record, account, or label for, or any false identification of, any fish or fish product which has been, or is intended to be imported, exported, transported, sold, offered for sale, purchased, or received in interstate or foreign commerce under the: (1) Tuna Conventions Act of 1950, (2) Northern Pacific Anadromous Stocks Act of 1992, (3) Pacific Salmon Treaty Act of 1985, (4) South Pacific Tuna Act of 1988, (5) Antarctic Marine Living Resources Convention Act of 1984, (6) Atlantic Tunas Convention Act of 1975, (7) Northwest Atlantic Fisheries Convention Act of 1995, (8) Western and Central Pacific Fisheries Convention Implementation Act, and (9) Northern Pacific Halibut Act of 1982. Declares that enforcement of specified titles or provisions of the preceding Acts and the Dolphin Protection Consumer Information Act be under this Act.

(Sec. 103) Amends the High Seas Driftnet Fishing Moratorium Protection Act to authorize the Secretary to: (1) develop, maintain, and make public a list of vessels and vessel owners engaged in illegal, unreported, or unregulated fishing (IUU), including vessels or vessel owners identified by an international fishery management organization; and (2) take appropriate action against listed vessels and vessel owners in accordance with U.S. and international law, including principles, rights, and obligations under international fishery management and trade agreements. Requires that action taken includes restricting the use of or access to ports or port services apply to all ports of the United States and its territories.

Applies provisions of the High Seas Driftnet Fishing Moratorium Protection Act related to withholding or revoking clearance or denying entry to certain large-scale driftnet fishing vessels, prohibiting the importation of fish and fish products and sport fishing equipment from certain nations, and determining whether such prohibitions are insufficient to cause nations to terminate large-scale driftnet fishing beyond their exclusive economic zone (EEZ) or to address IUU fishing or bycatching to certain nations with a negative certification and prohibits such provisions from applying to any identified nation with a positive certification, subject to exceptions.

Amends the High Seas Driftnet Fisheries Enforcement Act to direct the Secretary of the Treasury, in accordance with international law, to withhold or revoke clearance (provided by the Secretary of Homeland Security) and to deny entry of documented large-scale driftnet fishing vessels, or certain fishing vessels engaged in such IUU fishing or bycatching or of a nation receiving a negative certification to any U.S. place and to U.S. navigable waters.

(Sec. 104) Allows claims arising from the actions of any authorized officer taken pursuant to any scheme for at-sea boarding and inspection authorized under any international agreement to which the United States is a party to be pursued under the tort claims procedure specified in the federal judicial code, or other appropriate legal authorities.

Title II: Law Enforcement and International Operations - (Sec. 201) Requires, subject to appropriations, establishment of an interagency International Fisheries Enforcement Program in the Office of Law Enforcement of the National Marine Fisheries Service to detect and investigate IUU and to enforce this Act. Requires, on request, that the intelligence community collect information on IUU outside the United States about individuals who are not United States persons. Authorizes sharing fisheries-related data with federal, state, or foreign governments, the Food and Agriculture Organization of the United Nations (U.N.), or the secretariat or equivalent of an international fisheries management organization or arrangement made pursuant to an international fishery agreement. Authorizes appropriations.

(Sec. 202) Authorizes establishment of an international cooperation and assistance program, including grants, to support international capacity building. Includes in authorized activities providing to other nations: (1) funding and technical expertise to assist them in addressing illegal, unreported, or unregulated fishing activities; (2) funding and technical expertise to assist them in reducing the loss and environmental impacts of derelict fishing gear, reducing the bycatch of living marine resources, and promoting international marine resource conservation; and (3) funding, technical expertise, and training to aid them in building capacity for enhanced fisheries management, fisheries monitoring, catch and trade tracking activities, enforcement, and international marine resource conservation. Authorizes appropriations.

Title III: Miscellaneous Amendments - (Sec. 302) Amends the High Seas Driftnet Fishing Moratorium Protection Act to direct the Secretary to seek and foster the sharing of accurate, relevant, and timely information to: (1) improve scientific understanding, improve fisheries management, and improve compliance with conservation and management measures in international waters; (2) promote the conservation of protected living marine resources; and (3) combat IUU.

Authorizes information disclosure to the U.N.'s Food and Agriculture Organization, international fishery management organizations, or arrangements made under an international fishery agreement, if those organizations or arrangements have policies and procedures to safeguard the information from unintended or unauthorized disclosure.

(Sec. 303) Amends the High Seas Fishing Compliance Act to rewrite the provision that makes a high seas fishing permit valid for five years and to instead provide that a permit is voided if either one or more permits required for a vessel to fish expire, are revoked, or suspended, or the vessel is no longer eligible for U.S. documentation.

(Sec. 304) Amends the Pacific Salmon Treaty Act of 1985 to fix the compensation of the members of the Committee on Scientific Cooperation who are not state or federal employees.

(Sec. 305) Amends the Marine Mammal Protection Act to authorize appropriations to conduct a study of the effect of intentional encirclement (including chase) on dolphins and dolphin stocks incidentally taken in the course of purse seine fishing for yellowfin tuna in the eastern tropical Pacific Ocean.

Amends the Pacific Salmon Treaty Act of 1985 to authorize appropriations to the states of Alaska, Washington, Oregon, Idaho, and California for salmon habitat restoration, salmon stock enhancement, sustainable salmon fisheries, and salmon research, including the construction of salmon research and related facilities.

Amends the South Pacific Tuna Act of 1988 to authorize appropriations to carry out the Act and the Treaty on Fisheries Between the Governments of Certain Pacific Island States and the Government of the United States of America and its annexes, schedules, and implementing agreements.

Title IV: Implementation of the Antigua Convention - Antigua Convention Implementing Act of 2011 - (Sec. 404) Amends the Tuna Conventions Act of 1950 to modify or establish requirements regarding: (1) the number, appointment, and qualifications of commissioners of the Inter-American Tropical Tuna Commission; (2) the appointment, number, and compensation of the General Advisory Committee; and (3) the appointment and number of the Scientific Advisory Subcommittee.

(Sec. 406) Authorizes the Secretary: (1) to promulgate regulations to carry out U.S. international obligations under the Convention and the Tuna Conventions Act of 1950, including recommendations and decisions adopted by the Commission; (2) where the Secretary has discretion in the implementation of one or more measures adopted by the Commission and to the extent practicable within the Convention's implementation schedule, to promulgate such regulations in accordance with the procedures established by the Magnuson-Stevens Fishery Conservation and Management Act; and (3) to promulgate regulations applicable to all vessels and persons subject to the jurisdiction of the United States, including U.S. flag vessels wherever they may be operating, on whatever date the Secretary prescribes. (Among other things, current law that would be replaced by this amendment: (1) authorizes the Secretary of State to approve or disapprove of bylaws and rules adopted by each commission and submitted for U.S. approval; and (2) requires that regulations recommended by the Inter-American Tropical Tuna Commission or the International Commission for the Scientific Investigation of Tuna, if approved by the Secretaries of State and Commerce, be promulgated and applicable to all vessels and persons subject to U.S. jurisdiction.)

(Sec. 407) Revises the list of prohibited acts under the Tuna Conventions Act of 1950.

(Sec. 408) Requires that the Tuna Conventions Act of 1950 be enforced under this Act.

(Sec. 410) Repeals the Eastern Pacific Tuna Licensing Act of 1984.