The high seas are open to all states, whether coastal or land-locked. Freedom of the high seas, and particularly governance of high seas fishing, is exercised under the conditions laid down by the basic provisions contained in Part VII: High Seas of the 1982 UN Convention on the Law of the Sea (UNCLOS) and in the 1995 Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10 December 1982 Relating to the Conservation and Management of Straddling Fish Stocks And Highly Migratory Fish Stocks (also known as the UN Fish Stocks Agreement). UNCLOS provides, inter alia, for freedom of fishing in the high seas, subject to a number of conditions. It specifies the duties of flag states (Article 94), the duty to cooperate against piracy (Article 100), the rights of hot pursuit (Article 111), the right to fish in the high seas (Article 116), the duty of collaboration and negotiations for living resources management including through regional fishery bodies (Article 118), and the conservation of the living resources based on the best scientific evidence available and taking account of interdependence between stocks (Article 119).
The UN Fish Stocks Agreement aims "to ensure the long-term conservation and sustainable use of straddling fish stocks and highly migratory fish stocks through effective implementation of the relevant provisions of the Convention." It calls, inter alia, for more effective enforcement by flag states, port states and coastal states of the conservation and management measures adopted for such stocks. It refers to sustainability, best scientific evidence, dependent and associated species, pollution, waste, fishing by lost gear ("ghost fishing"), artisanal fisheries people's interests, fisheries research and monitoring, control and surveillance (MCS). It strengthens the UN Convention in many areas, including the application of the precautionary approach (Article 6), compatibility between management measures taken in EEZs and the high seas (Article 7), cooperation for conservation and management (Article 8), subregional and regional fisheries management organizations and arrangements (Article 9 to 13), research (Article 14), and enclosed and semi-enclosed seas (Article 15), and areas of high seas surrounded entirely by an area under the national jurisdiction of a single state, as with the Peanut hole (Article 16). It specifies the duties of the flag state (Article 18 and 19) and port state (Article 23), and peaceful settlement of disputes (Article 27-30).
High seas resources are usually managed through regional fishery organizations in charge of organising the international cooperation around the following tasks: collection of fishery statistics; assessment of the state of resources; analyses of management options and provision of scientific advice for management; management decisions; and monitoring. The implementation and enforcement of the measures usually remains a flag State prerogative. The main difficulties encountered by these bodies include: the cost and quality of the information needed for management; the difficulty to agree on biological objectives (and reference points); the quasi-impossibility to objectively deal with economic and social issues; the inadequacy and inefficiency of their enforcement powers; the difficulty to agree on specific resource allocation; the lack of relation between national quotas and fleet size; the lack of focus or interest on environmental impacts of fishing (including bycatch and discards); the low level of collaboration with international conventions in charge of the environment; the difficulty to implement the precautionary approach; and the growing importance of NGOs and public opinion with the related demand for higher transparency and participation.
The FAO Code of Conduct on Responsible Fisheries integrates all of the requirements of the two instruments above, bridging them also with more general requirements from the UN Convention on Environment and Development (UNCED).