Some problems of the management of shared stocks

The paper discusses the problems facing countries when managing stocks of fish that move between their EEZs and the EEZs of adjacent countries, or onto the high seas. The action needed depends on the pattern of movement of the stocks. The different patterns of movement are discussed; they vary from small local dispersions in which only a small proportion of the stock cross boundaries between national EEZs to long migrations in which virtually all the stock may move from one EEZ to another. Collaboration between countries in research on shared stocks is always beneficial, and should not raise any serious problem. Collaboration in choosing and implementing management measures can be more difficult. The problems raised, and the nature of collaboration required to achieve effective management are discussed in relation to the different patterns of movement.