View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by PubMed Central Feature Troubled Waters: The Future of Global Fisheries Virginia Gewin t is becoming increasingly apparent contributions to the dramatic declines depletion of the majority of the largest that the vast blue expanse of in global fi sheries. Delving into the ocean predators. While some have Iocean—the last frontier—is not past, Jeremy Jackson and colleagues valid criticisms of the assumptions and as inexhaustible as it once seemed. (2001) combined local historic records aggregation of historic data used to While we have yet to fully explore the assess the global situation, few disagree reaches of the sea, technology has with the overriding conclusion that granted humans the ability to harvest humans have drastically altered not its wealth. We can now fi sh anywhere, Atlantic cod in Canadian at any depth, for any species. Like the waters suffered a total Copyright: © 2004 Virginia Gewin. This is an open-ac- American frontier range’s bison and cess article distributed under the terms of the Cre- ative Commons Attribution License, which permits wolf populations brought to the brink population collapse and unrestricted use, distribution, and reproduction in of extinction swordfi sh and sharks any medium, provided the original work is properly are the ocean’s most pursued prizes. are now on Canada’s cited. The disadvantages associated with the endangered species list. Abbreviations: CSIRO, Commonwealth Scientifi c and depth and dimensions of this open Industrial Research Organisation; FAO, Food and range, however, have long obscured the Agriculture Organization; GBRMPA, Great Barrier Reef Marine Park Authority; IATTC, Inter-American real consequences of fi shing. Indeed, Tropical Tuna Commission; IUU, illegal, unreported, scientists have the formidable challenge with current estimates to detail the and unregulated; MPA, marine protected area; NMFS, of assessing the status of species whose ecological impacts of overfi shing, National Marine Fisheries Service home covers over 75% of the earth. Reg Watson and Daniel Pauly (2001) Virginia Gewin is a freelance writer based in Three recent highly publicized drew attention to distortions of global Portland, Oregon, United States of America. E-mail: [email protected] papers—a trifecta detailing troubled catches, and Ransom Myers and waters—call attention to overfi shing’s Boris Worm (2003) highlighted the DOI: 10.1371/journal.pbio.0020113 PLoS Biology | http://biology.plosjournals.org April 2004 | Volume 2 | Issue 4 | Page 0422 only fi sh biodiversity, but, increasingly, the ocean itself. Box 1. Fisheries Management in Developing Recent reports by the United Nation’s Food and Agriculture Countries Organization (FAO) which maintains While industrial-scale fi shing is a growing concern to fi sheries biologists, the management the world’s most complete global of subsistence fi shing in developing countries is equally complex. Indonesia alone has fi sheries database, appear to validate 1.3 million fi shers. Given the lack of alternative economic options for subsistence fi shers, the conclusions of these studies. The it is much more diffi cult to reduce fi shing because it meets immediate food and resource most recent FAO report states that needs. Local scientists, often lacking in resources, have a much more diffi cult time assessing 28% of global stocks are signifi cantly the effects and offering advice to governmental fi sheries regulators, who have limited depleted or overexploited, and 47% political infl uence. Kenyan researcher Tim McClanahan notes that a main problem is a lack are either fully exploited or meet the of coordination and respect between traditional and national programs of management. target maximum sustainable yield. Therefore, he focuses on the fi shing gear used. By reconciling the impact of certain fi shing Only 24% of global stocks are either gear with traditional knowledge, McClanahan has developed a basis for suggested restrictions under- or moderately exploited. As deemed acceptable to the local community. the sea is increasingly harvested, many ecologists wonder how the ecosystem will continue to function (Jackson et al. 2001). Although economic and WorldFish in Penang, Malaysia, notes with the Inter-American Tropical social considerations often supercede that the Asia-specifi c database called Tuna Commission (IATTC) (La Jolla, scientifi c assessments, science will TrawlBase (www.worldfi shcenter. California, United States). continuously be called upon to org/trawl/) confi rms that the region’s Couple these inadequacies with deliver management options that will commercial species have been depleted previously unknown bycatch rates (i.e., straddle the needs for conservation to 10%–30% of what they were 30–40 the fi sh caught in addition to the target and production, even in areas where years ago. catch) and illegal catches, and it is easy there is only subsistence fi shing (Box Obtaining accurate information to see that the task is formidable. The 1). As scientists debate the details of on highly migratory species is FAO estimates that roughly one-quarter global fi sheries assessment, they are challenging, to say the least. It is not of the marine commercial catch also including studies of the long- hard to imagine that data quality is the destined for human consumption— term ecosystem effects and options for biggest disadvantage to any scientifi c some 18–40 million metric tons of recovery efforts. Like was done on the assessment. Of the 50 managed stocks fi sh—is thrown back in the sea, a open range, shall we conserve or farm in the northeast Atlantic Ocean— harvested catch that is never utilized the sea—or both? including invertebrates, sport fi shes, or counted. It is estimated that the and major commercial fi nfi sh—data illegal, unreported, and unregulated Catches, Collapses, and are kept on only one-fi fth of the (IUU) fi sheries surpass allowed fi shing Controversies species. There are 250 fi sh species in quotas by 300%. IUU fi shers operate The FAO began keeping fi sheries the region, but only 55 species are in areas where fi shing is not permitted, records in 1950. Unfortunately, an of commercial interest and merit use banned technologies or outlawed enormous amount of data comes inquiry. “We know next to nothing net types, or underreport catches. “The directly from each country’s fi shing about noncommercially fi shed species,” IUU fi shery for Patagonian toothfi sh industry, which is often biased as expanded rapidly in the mid-1990s, a result of unreported discarding, likely on the order of 20–30 vessels,” illegal fi shing, and the misreporting Bottom trawling not only says Andrew Constable, an ecological of harvests. For example, mid-level modeler at the Australian Antarctic Chinese government offi cials seeking removes [targeted] fi sh Division (Kingston, Australia), who also promotions systematically enhanced from seafl oor habitats, but works with the Scientifi c Committee of China’s fi sheries numbers in recent the Commission for the Conservation years—which infl ated and skewed compromises the ability of of Antarctic Marine Living Resources international catch rates. (Hobart, Australia). “These rates of The FAO data show that catches, other fi sh to survive. IUU fi shing could reduce stocks to excluding a recent surge in anchoveta threshold levels in some areas in two to and China’s suspect numbers, reached fi ve years,” he adds. a peak of 80 million metric tons in notes Jeff Hutchings, a conservation Often overlooked is the inescapable the late 1980s and have since begun biologist at Dalhousie University fact that even sustainable harvest rates to decline. Regional studies validate (Halifax, Nova Scotia, Canada). And reduce fi sh populations quickly. “If these trends. “Most of the line fi sh that is where fi sheries have adequate the goal is a productive fi shery, we’re around the coast of South Africa access to current monitoring programs. automatically talking about up to a are depleted to 5%–15% of pristine “With the recent expansion of the 70% decline in population across the levels,” says George Branch, a marine Taiwanese and Chinese fl eets, we don’t board,” says Deriso. The FAO’s Chief of biologist from the University of Cape have the kind of sampling programs Marine Resource Services, Jorge Csirke, Town (Cape Town, South Africa). needed for those kinds of fi sheries,” states that “from a stock point of view, Meryl Williams, Director General of says Rick Deriso, a fi sheries scientist there is no way to preserve integrity PLoS Biology | http://biology.plosjournals.org April 2004 | Volume 2 | Issue 4 | Page 0423 of wild stocks and exploit them at the decades of abundant resources. “They basic biological data are missing makes same time.” Indeed, the United States’ brought the approach of single-species the job even harder. While knowledge National Marine Fisheries Service management to near-perfection,” of these components is still quite (NMFS) considers optimal harvest says Boris Worm, a marine ecologist spotty, tuna inventories, for example, rates to be between 40%–60% of virgin at the Institute for Marine Science in have started collecting gender data on levels. But once fi sh populations dip Kiel, Germany. A growing discontent catches. below the 10%–20% mark, declines are with the model, in addition to greater of serious concern. awareness of ecological interactions, Atlantic cod in Canadian waters however, prompted Worm and his “The big mistake is suffered a total population collapse Dalhousie University colleague Ransom and are now on Canada’s endangered Myers to question the sustainability of suggesting that you can species list (Figure 1). From 2 billion the single-species approach. Attempting breeding individuals in the 1960s, a comprehensive assessment, their manage fi sh stocks.… We Atlantic cod populations have declined widely cited recent paper (Myers and can only manage human by almost 90%, according to Hutchings.