optimal harvest rates are subject to considerable error. In such circumstances, a conservative approach to setting allowable harvests would reduce the risk of biological overharvesting, and thus jeopardy to future harvests. Conservative fishery managers, however, frequently encounter intense pressure from elements of the harvesting community who may expect to gain more from an immediate increase in allowable harvest than from an uncertain investment in the size of the breeding stock.
The economic objective of fishery managementto increase economic rent by reducing harvesting costs relative to the value of the harvestperhaps has been more difficult to achieve than the biological objectives. Fishery managers have found that, when regulations limit effort along one dimension (e.g., days open to fishing), competition reappears along other dimensions (e.g., more boats or larger, faster boats).
Although it is a challenging task to achieve efficient management of a fishery that is confined to a single jurisdiction, further complications emerge when the targeted fish population migrates across international boundaries or straddles the boundary between a national jurisdiction and the international commons of the open ocean. In the case of a coastal fish population that migrates across international boundaries, harvesting in each jurisdiction affects the availability of fish in the other jurisdiction. If these nations harvest the shared stock competitively, they will tend to squander its potential value. Recognizing that possibility, they may attempt to work out a cooperative division of the harvest, but maintaining cooperation is particularly difficult when there are large natural variations in the size, location, or migratory patterns of the fish population.
Uncertainty regarding the magnitude and sources of variations in fish stocks is often a stumbling block to cooperative harvest management. For example, when the availability of fish declines, it may not be immediately apparent if the cause was excessive harvesting by the neighboring nation or a natural fluctuation in abundance. In addition, the parties may have different information or beliefs about how the stock is changing and they may have a strategic interest in concealing that information from one another, or in promoting a particular interest-laden interpretation of the biological facts.
In such circumstances, it is possible that improved information on the links between climatic variations and fish populations could reduce uncertainty and allow the parties to forge a common view as to their best joint harvesting policy. If so, the likelihood of breakdowns in cooperation and associated economic losses might diminish. The extent to which improved seasonal-to-interannual climate forecasts can contribute to improved fishery management is likely to depend on the nature of the management institutions and on the clarity of the links between climate and changes in the fish population.