Formal analyses of long-term global marine fisheries prospects have yet to be performed, claims a new paper in the journal Science, because "fisheries research focuses on local, species-specific management issues." This is despite the fact that the past decade "established that fisheries must be viewed as components of a global enterprise." However, the paper continues, the time has come "to look at the future of fisheries through (i) identification and extrapolation of fundamental trends and (ii) development and exploration (with or without computer simulation) of possible futures." The authors of the Science paper attempt to do just that.

Although extrapolation of some trends, for example bottom fisheries, is relatively straightforword - "With satellite positioning and seafloor-imaging systems, we will deplete deep slopes, canyons, sea mounts, and deep ocean ridges of local accumulations of bottom fishes" - predictions are "better embedded into scenarios - sets of coherent, plausible stories designed to address complex questions about an uncertain future." To this end, the paper examines four scenarios drawn up by the United Nations Environment Program, in which different priorities shape different management approaches:

• Markets First, where "market considerations shape environmental policy." This might have some benefits such as "the gradual elimination of the subsidies fueling over fishing," as well as "the suppression of IUU [illegal, unregulated, and unreported] fishing . which distorts economic rationality." It might also lead to a global fisheries industry "targeting profitable, mostly small, resilient invertebrates and keeping their predators (large fishes) depressed. Shrimp trawlers presently operate in this way, with tremendous ecological impacts on bottom habitats."

  Security First, where "conflicts and Inequality lead to strong socioeconomic boundaries between rich and poor." This scenario would see the continuation of 'fishing down marine food webs', including in the High Arctic, and the "subsidization of rich countries' fleets to their logical ends, including the collapse of traditional fish stocks." It would also" largely eliminate fish from the markets of countries still 'developing' in 2050 . [and] would also increase exports of polluting technologies to poorer countries, notably coastal aquaculture and/or fertilization of the open sea. This would have negative impacts on the remaining marine fisheries in the host countries, through harmful algal blooms, diseases, and invasive species."

  Policy First, under which "a range of actions is undertaken by governments to balance social equity and environmental concerns." Under this scenario, regulatory reforms, "coordinated between countries, combined with marine reserve networks, massive reduction of fishing effort, especially gears that destroy bottom habitat and generate large "bycatch", and abatement of coastal pollution, may bring fisheries back from the brink and reduce the danger of extinction for many species."

  Sustainability First would "require a value system change, favoring sustainability . would involve creating networks of marine reserves and careful monitoring and rebuilding a number of major stocks . [and would require] strong decreases in fishing effort, typically to 20 to 30% of current levels, and a redistribution of remaining effort across trophic levels, from large top predators to small prey species."

The paper concludes that the scenarios "describe what might happen, not what will come to pass." Its authors note, however, that many of the fisheries they studied, for example in the North Atlantic or Gulf of Thailand, "presently optimize nothing of benefit to society . [and it] is doubtful that they will be around in 2050."

December 2003.