This mismatch between jurisdiction and the habitat of fish stocks creates difficulties in the management of stocks. Without cooperation between states, within whose jurisdiction the stocks fall, states may individually adopt management measures that collectively do not result in optimal and sustainable utilization of those stocks. The UN Convention on the Law of the Sea (UNCLOS) requires that coastal states co-operate in the management of such stocks (Art.63 (1)) but establishes no rules for doing so.
Outside the 200 nautical miles exclusive economic or fisheries zone, the absence of clear jurisdiction over fishing threatens the effective management of stocks whose range straddles the outer limit of the zone, as well as those that migrate widely on the high seas. The regime governing straddling stocks (14.3% of total marine catch in 1994) and highly migratory species (5.4% in 1994) affect about 20% of the global marine catch. Coupled with the stocks that fall within the jurisdictions of two or more states, both inland and marine, the effectiveness of cooperative arrangements between states that have an interest in such fisheries has a significant impact on sustainable use of aquatic resources.
There are many instances where cooperative arrangements have not been made at all for the management of transboundary stocks, sometimes as a result of one party having less interest than the other party in establishing such arrangements. If one party does not wish to co-operate in a management arrangement of joint stocks, the only redress is for an appeal to be made to the international commitments made by that state, and to the manifest advantages to be gained by co-operation.
In instances where states cooperate but do not reach proper agreement over the shares of a stock, the consequence may be that, collectively, they consistently harvest more than what is supported by the best scientific advice available. Unresolved issues between states, whether they relate to shares of the catch or some other disagreement, often stem from the absence or inadequacy of mechanisms for resolving disputes.
In establishing management authorities for shared fisheries resources, particular attention needs to be given to the decision making process and to binding dispute-settlement mechanisms, so that when disputes do arise, there is an already agreed method for resolving them.
The importance of ecosystem-wide management of fisheries resources is well established. The fact that jurisdictions often divide aquatic ecosystems creates a particular challenge for effective fisheries management. There are a number of examples of successful cooperative arrangements between states that demonstrate that such arrangements can work well.
The Code of Conduct for Responsible Fisheries identifies, as a general principle, that "States and users of living aquatic resources should conserve aquatic ecosystems" (Article 6.1). It is also emphasized in the Code that "to be effective, fisheries management should be concerned with the whole stock unit over its entire area of distribution" (Article 7.3.1). The 1999 Rome Declaration on the Implementation of the Code of Conduct for Responsible Fisheries reaffirmed that the 126 participating states "accord the high priority to achieving sustainability within the framework of the ecosystem approach" (para. 12(c)).
The Agreement to Promote Compliance with International Conservation and Management Measures by Fishing Vessels on the High Seas, usually referred to as the Compliance Agreement, provides a dispute settlement procedure (Article IX) which could be more specifically incorporated into bilateral or multilateral agreements. In addition, the 1982 Law of the Sea Convention ( Part XV) and the 1995 Fish Stocks Agreement (Part VIII) both provide procedures for the settlement of disputes.
The growth in the number of regional fisheries management organizations and the success of some of them, particularly in instances where binding dispute settlement mechanisms have been agreed, points to the possibility of the successful joint management of shared fish stocks becoming the norm.