The United Nations Convention on the Law of the Sea (UNCLOS), adopted on 10 December 1982 (United Nations, 1982) and which entered into force on 16 November 1994, established overarching rules governing all uses of the world's oceans and seas and their resources. Of particular relevance to fisheries are their Part V (articles 55 to 75) on the Exclusive Economic Zone (EEZ), and Part VII on the High Seas (articles 86 to 120).
UNCLOS recognizes the sovereign rights of the coastal States for the purpose of exploring and exploiting, conserving and managing fishery resources in their EEZs, calling upon the coastal States to adopt conservation and management measures to promote the optimum utilization of fishery resources in their EEZs. With respect to exploited stocks or stocks of associated species occurring both within the EEZ and in the area beyond and adjacent to the zone, UNCLOS calls upon the coastal States and States fishing in the high seas to seek agreement upon the measures necessary for the conservation of those stocks in the adjacent high seas area. UNCLOS also calls upon the coastal States and other States fishing highly migratory species to cooperate in ensuring conservation and promoting the optimum utilization of those resources in their whole area of distribution. With respect to the high seas, UNCLOS also recognizes the free access and the freedom of fishing to all States, calling upon all States and particularly upon States fishing to cooperate in the conservation and management of fishery resources occurring in the high seas.
Fishing in what is now the high seas was not perceived as a major problem requiring priority attention during the negotiating process of UNCLOS. Therefore, with respect to the highly migratory and other fishery resources occurring partly or entirely in the high seas, UNCLOS limited itself to providing general principles for their conservation, optimum utilization and management, calling upon all States to cooperate towards the further development and implementation of these general principles. However, as UNCLOS was being adopted and as more coastal States claimed their rights and jurisdiction over fisheries in their EEZ, large distant-water fishing fleets were displaced from some of their traditional coastal fishing grounds and the pressure to fish in the high seas grew rapidly and without much control. Inadequate management and overfishing soon became problems in the high seas, and thus the increased need to control and reduce fishing fleets operating on the high seas as there were indications that excessive fishing was jeopardizing the sustainability of high seas fishery resources, as was highlighted by FAO (1992) in reporting to the Twentieth Session of its Committee on Fisheries (FAO, 1993).
Growing concerns of the international community regarding the state of fishery resources being exploited beyond the areas under national jurisdiction was influential in prompting a decision by the United Nations to convene an international Conference on Straddling Fish Stocks and Highly Migratory Fish Stocks. An important contribution to the convening of this conference was the Declaration of Cancun, adopted at the International Conference on Responsible Fishing convened by the Government of Mexico in collaboration with FAO in May 1992 (FAO, 1995). The Declaration of Cancun stated that "States should cooperate on bilateral, regional and multilateral levels to establish, reinforce and implement effective means and mechanisms to ensure responsible fishing on the high seas, in accordance with the relevant provisions of the United Nations Convention on the Law of the Sea". The Declaration of Cancun was brought to the attention of the United Nations Conference on Environment and Development (UNCED), held in Rio de Janeiro, 3 - 14 June 1992, were it was agreed that a United Nations Conference on Straddling Fish Stocks and Highly Migratory Fish Stocks would be convened with the general mandate of promoting effective implementation of the provisions of the United Nations Convention on the Law of the Sea on straddling fish stocks and highly migratory fish stocks. UNCED also recommended that the Conference should identify and assess existing problems related to the conservation and management of such fish stocks, consider means of improving fisheries cooperation among States, and formulate appropriate recommendations. The mandate to convene an international Conference on Straddling Fish Stocks and Highly Migratory Fish Stocks was endorsed by the UN General Assembly in its resolution 47/192 of 22 December 1992.
The first session of the United Nations Conference on Straddling Fish Stocks and Highly Migratory Fish Stocks was held in New York, 19 - 23 April 1993, and during its sixth session on 4 August 1995 the Conference adopted without a vote the 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 1995 United Nations Fish Stock Agreement, or just as the Fish Stock Agreement [United Nations, 1995]), thus discharging the mandate given by General Assembly resolution 47/192.
The United Nations Fish Stock Agreement (FSA) entered into force on 11 December 2001 with expectations that it would become a blueprint for the management of high seas fisheries. Specifically, it addressed management of stocks of highly migratory species and of straddling fish stocks. Fisheries for other fishery resources found as high seas fish stocks, that were not explicitly addressed in the FSA, have emerged in recent years. In order to assist in the overall assessment of fish stocks and fisheries in the high seas following the entering into force of the FSA, this document describes highly migratory fish stocks, straddling fish stocks, and stocks of other high seas fishery resources and the fisheries for them, including information on their state of exploitation. It also considers the effects of fisheries for these resources on associated species and ecosystems. Lastly, it highlights issues that need to be addressed in implementing the FSA and to improve its performance in the future. An earlier and much shorter version of this document was contributed for the preparation of the United Nations General Assembly document A/Conf.210/2006/1, issued for the May 2006 Review Conference of the FSA.
About 200 species have been identified as being fished on the high seas either as highly migratory species, straddling fish stocks or stocks of other high seas fishery resources. Although there is insufficient scientific information to determine the actual number of stocks involved in these fisheries, around 230 species (or species group) statistical area combinations are reported on as stocks in this report. The number of species and stocks are similar since many species occur in multiple stocks, but many stocks are made up of groups of more than one species.
As described in other sections of this document the total reported catch in 2004 of highly migratory species is 5.1 million tonnes, and this is dominated by catches of tuna and tuna-like species (4.8 million tonnes). The total catch of oceanic epipelagic and deep-water species, that are the most likely to form straddling fish stocks and stocks of other high seas fishery resources was 5.6 million tonnes in 2004. It is noted, however, that an unknown but certainly large proportion of this catch occurs within EEZs and part of it comes from stocks that are entirely within EEZs (therefore, from non-straddling and non-high seas stocks). Furthermore, some neritic and more coastal species usually entirely within the EEZs may also form straddling stocks and other stocks occurring entirely in the high seas in those few areas where the continental shelf and slope, or the effect of coastal enrichment processes extend beyond the EEZs. Available data in global databases is insufficient to distinguish catches from straddling stocks from those on other stocks occurring in the high seas, or from those on entirely EEZ stocks.