ill-defined property rights, overcapitalization and excess fishing capacity, inadequate statistics and scientific information, lack of attention to whole ecosystems or to nonfished ecosystem components, lack of predictability owing to environmental and other fluctuations, and mismatches between the time and space scales of fisheries (including fishers) and management institutions. The factors are not mutually independent; several of them derive from the existence of others. It is impossible with present knowledge to assign relative weights to the contributions of those factors to the overall problem and perhaps it always will be. However, the factors do provide a framework for recommendations to improve the sustainability of marine fisheries. Therefore, the committee has focused on recommendations that are likely to improve the sustainability of marine fisheries, whatever the causes of the current difficulties. It has also tried to emphasize recommendations that lead to identifiable actions.
The committee recommends the adoption of an ecosystem-based approach for fishery management to reduce overall fishing mortality. Its goal should be to rebuild and sustain populations, species, biological communities, and marine ecosystems at high levels of economic and biological productivity and biological diversity, so as not to jeopardize a wide range of goods and services from marine ecosystems, while providing food, revenue, and recreation for humans. An ecosystem-based approach that addresses overall fishing mortality will reinforce other approaches to substantially reduce overall fishing intensity. It will help produce the will to manage conservatively, which is required to rebuild depleted populations, reduce bycatch and discards, and reduce known and as-yet-unknown ecosystem effects. Although this approach will cause some economic and social pain at first, it need not result in reduced yields in the long term because rebuilding depleted fish populations should offset a reduction in fishing intensity and increase the future sustainable yields.
Adopting a successful ecosystem-based approach to managing fisheries is not easy, especially at a global or even continental scale. That is why the committee's recommendations include incremental changes in various aspects of fishery management. The elements of this approach, many of which have been applied in single-species management, are outlined below. They include assignment of fishing rights or privileges to provide conservation incentives and reduce overcapacity, adoption of risk-averse precautionary approaches in the face of uncertainty, establishment of marine protected areas, and research. These significant steps that must be taken to make ecosystem approaches to fishery management successful are not entirely new concepts, although they are not easy to implement. As such measures are being implemented, more innovative management tools and techniques, such as marine protected areas, ''virtual communities," and ecosystem modeling for fishery management, can be tested and implemented.