Global fish catches are falling three times faster than official UN figures suggest, according to a landmark new study, with overfishing to blame. 
 
 Seafood is the critical source of protein for more than 2.5 billion people, but over-exploitation is cutting the catch by more than 1m tonnes a year. 
 
 The official catch data, provided by nations to the UN’s Food and Agriculture Organisation (FAO), rarely includes small-scale, sport or illegal fishing and does not count fish discarded at sea. To provide a better estimate, more than 400 researchers around the world spent a decade finding other data to fill in the gaps. 
 
 The results, published in the journal Nature Communications, show the annual catches between 1950 and 2010 were much bigger than thought, but that the decline after the peak year of 1996 was much faster than official figures. 
 
 The FAO data indicated a catch of 86m tonnes in 1996, then a decline of 0.4m tonnes per year. In contrast, the new research estimates the peak catch was 130m tonnes, but declined at 1.2m tonnes per year afterwards. 
 
 “Our results differ very strongly from those of the FAO,” said Prof Daniel Pauly, at the University of British Columbia in Canada and who led the work. “Our results indicate that the decline is very strong and is not due to countries fishing less. It is due to countries having fished too much and having exhausted one fishery after another.” 
 
 Estimating subsistence, small-scale and illegal fishing is difficult, but Pauly said his team was confident in its results which - unlike the FAO data - includes estimates of the uncertainty. “This research is not based on a few studies here and there and then extrapolation,” he said. “It is based on the results of 200 studies we have conducted for about a decade by a network of 400 people in all countries of the world.” 
 
 The researchers used many different approaches to fill in the missing data, from hotel invoices for locally bought fish in the Bahamas to information on local fish consumption. 
 
 “This work has been carefully conducted by painstaking research into the hidden underbelly of global fishing, country by country, region by region” said Prof Boris Worm, at Dalhousie University in Canada and not involved in the new research. “This was a Herculean task that no one else has ever attempted. While the results necessarily remain uncertain, they undoubtedly represent our most complete picture yet of the global state of fish catches.” 
 
 Worm said the world’s fisheries were being over-exploited but that some stocks were being sustainably managed: “Where such measures have been taken, we find that both fish and fishermen are more likely to persist into the future.” 
 
 Global fish catches rose from the 1950s to 1996 as fishing fleets expanded and discovered new fish stocks to exploit. But after 1996, few undiscovered fisheries were left and catches started to decline. “It was never really sustainable,” said Pauly. The decline since 1996 has largely been in fish caught by industrial fleets and to a lesser extent a cut in the number of unwanted fish discarded at sea. 
 
 “The fact that we catch far more than we thought is, if you like, a more positive thing,” he said. “Because if we rebuild stocks, we can rebuild to more than we thought before.” 
 
 There has been success in some places where fishing has been restricted for a few years, for example in the Norwegian herring and cod fisheries. On resumption, catches were bigger than ever. 
 
 But Pauly said: “I expect a continued decline because I don’t expect countries to realise the need to rebuild stocks. I don’t see African countries, for example, rebuilding their stocks, or being allowed to by the foreign fleets that are working there, because the pressure to continue to fish is very strong. We know how to fix this problem but whether we do it or not depends on conditions that are difficult.” 
 
 A 2015 study showed nearly 500 Chinese fishing vessels operating off west Africa, with scores of cases of illegal fishing, according to Greenpeace. Large European vessels also operate in the region. In April 2015, the EU threatened Thailand with a trade ban over illegal fishing, while in September, Greenpeace said it had identified significant pirate fishing for tuna in the Pacific. 
 
 Prof Callum Roberts, at the University of York in the UK and not part of Pauly’s team, said: “This is a superb piece of research. Greater knowledge of what we have done and are still doing will help us to change for the better.” 
 
 “We can see more clearly now, for example, the immense value of fish to poor people in developing countries,” he said. “We can see how industrial fisheries from developing countries are robbing these people of livelihoods and food. We can also see, that in efforts to stem declines, we have been using more and more bycatch that was once thrown away.” ||||| Fish are placed in a bucket at Central Europe's biggest fish pond complex in the Great Hungarian Plain at Hortobagy, 200km (124 miles) east from Budapest, November 30, 2010. 
 
 VANCOUVER | 
 
 VANCOUVER (Reuters) - The world's fishing industry is fast running out of new ocean fishing grounds to exploit as it depletes existing areas through unsustainable harvesting practices, according to a study published Thursday. 
 
 Expansion into unexploited fishing grounds allowed global catches to increase for decades, and disguised the fact that older areas were being depleted, according researchers at the University of British Columbia and National Geographic. 
 
 "We knew the expansion was going on, but this is the first time we have quantified it," said Daniel Pauly, a scientist at the Vancouver-based university who co-authored the report published in the online journal PLoS ONE. (here) 
 
 About 19 million tons of fish were landed in 1950, and that increased to a peak of 90 million tons a year in the late 1980s, according to the researchers, who looked at data from 1950 to 2005. 
 
 The researchers tracked the expansion of fishing activity using computer models that examine both the total number of fish caught and the impact that catching different types of fish has had on the ocean's productivity. 
 
 By the late 1990s, the world's fishing fleets had largely run out of new fishing grounds to exploit, the researchers said. 
 
 Consumers have a romantic view of fishers being local business people, but most fishing is done by large companies, according to Pauly, who said these companies can ignore the decline of older stocks by simply moving to new areas. 
 
 The data shows more must done to ensure existing fish stocks are protected, said the researchers, who have done other studies outlining problems with the world's fish supplies. 
 
 "The sooner we come to grips with it ... the sooner we can stop the downward spiral by creating stricter fishing regulations and more marine reserves," co-author Enric Sala said in a statement. 
 
 The researchers said that in 1950 most heavy fishing was done in the North Atlantic and the Western Pacific, but by the mid 1990s, a third of the world's oceans and two-thirds of the continental shelves were exploited. 
 
 That expansion has left only unproductive fishing areas on the high seas and the ice-covered waters of the Arctic and Antarctic for boats to move into. 
 
 Some other researchers have complained that recent studies warning the oceans are being depleted of larger fish are making the situation appear worse than it really is. 
 
 Pauly said those critics have ignored the role that the move of the fleet into new fishing grounds has on fish-catch data, which is documented in the current study. 
 
 (Reporting Allan Dowd, editing by Peter Galloway) ||||| Commonly cited statistics have understated the size of the global seafood catch by about 30%, a new tally finds. The estimate, drawn in part from a painstaking effort to gather statistics on poorly documented subsistence, recreational, and illegal fisheries, suggests that the world catch has also declined more steeply since the 1990s than official figures indicate. 
 
 Overall, fishers caught an estimated 109 million metric tons (mt) of fish in 2010, researchers report today in Nature Communications. That’s well above the 77 million mt that nations reported to the Food and Agriculture Organization (FAO) of the United Nations, which keeps global catch statistics. 
 
 The reconstructed 2010 catch was 15% below peak landings of 130 million mt in 1996, estimate the researchers, who are based at the University of British Columbia (UBC), Vancouver in Canada. In contrast, FAO figures for the same 14-year period showed an 11% decline, from 86 million mt to 77 million mt. 
 
 The researchers also suggest that incomplete statistics have led FAO to make questionable pronouncements: Not long ago, they note, one of the agency’s reports described global catch levels as “practically stable.” The new figures challenge that idea, the researchers say. 
 
 FAO officials, however, are pushing back against the validity of the new numbers. “Comparing reconstructed catches with FAO statistics would be like comparing apples and oranges,” wrote Marc Taconet, chief of FAO’s Fishery Statistics and Information Branch in Rome, in an email. He added that based on “several sources of biases in the [study’s] method and the wide uncertainty ranges, we express reservations that the paper’s conclusions of declining catch trends can be strongly opposed to FAO’s reports of stable capture production trends in recent years.” 
 
 Many fisheries scientists have long been skeptical of the completeness of FAO’s statistics. The agency relies on national governments to estimate all of their catch except discards, and many nations don’t have the interest or capacity to tally landings from artisanal, subsistence, and recreational fisheries. And some nations have over- or underreported catches for political reasons, or ignored illegal landings, further complicating efforts to understand how fish stocks—a key source of protein—are faring. 
 
 To try to fill those gaps, researchers with the Sea Around Us project at UBC tapped into a worldwide network of colleagues. Over more than a decade, they attempted to reconstruct historic catches by scouring a range of sources, including academic papers, government websites, and reports gathering dust in local libraries and government archives. 
 
 The biggest surprise, says lead author Daniel Pauly of UBC, was the size of the artisanal and subsistence catches, primarily in the developing world: They amounted to 25% of the total. Overall, these catches slightly increased during the study period as more people participated, the researchers found. 
 
 These fisheries are also putting worrying pressure on many fish stocks, the study concluded. In small island countries sprinkled across the Pacific and the Caribbean, for instance, Pauly says, “the situation is much worse than anyone knew: the catches of local reef fish were crashing all over the place and the government officials didn’t know or care.” Pauly hopes the study “will get governments to focus more on their local fisheries.” 
 
 Shrinking industrial landings, however, were responsible for most of the recent global catch decline, the researchers concluded. Industrial landings, which make up about 75% of the global total, dropped by about 2% a year between the 1990s and 2010, they estimate. 
 
 Some eye-popping findings emerged from the examination of the industrial catch, the researchers say. West African nations, for instance, historically appear to have reported to FAO just 40% of the catches made by local vessels in near-shore waters, found UBC’s Dyhia Belhabib. And foreign vessels that lacked licenses to fish in those waters accounted for just over one-half of the offshore catch, she found. 
 
 Such findings highlight the need for nations, and FAO, to improve record keeping, the authors say. Better numbers, they add, will be essential to developing policies to protect a key food source. “Fish stocks are like bank accounts,” says co-author Dirk Zeller, senior scientist and executive director of Sea Around Us. “You need to know how much there is, and at what interest rate your money’s growing, so you can decide how much you want to take out.” 
 
 One step FAO could take, the authors say, is asking nations to report both documented and estimated catches. “Most countries use extensive estimation, approximation and raising procedures, especially in developing countries,” Zeller says. “Hence essentially all countries could estimate uncertainties around their reported data if they chose.” 
 
 “We concur with the paper’s call upon countries’ responsibilities for improving reporting and for mobilizing funding resources,” FAO’s Taconet said, adding that the agency “always welcomes research efforts. … This type of research is crucial for stimulating international discussion on unreported catches.” 
 
 What the reconstruction team has done “is monumental!” wrote Trevor Branch, a fisheries scientist at the University of Washington, Seattle, in an email. Although he doubts all of the numbers are accurate, he expects the data will improve over time as more specialists contribute to the database. ||||| Using estimates of the primary production required (PPR) to support fisheries catches (a measure of the footprint of fishing), we analyzed the geographical expansion of the global marine fisheries from 1950 to 2005. We used multiple threshold levels of PPR as percentage of local primary production to define ‘fisheries exploitation’ and applied them to the global dataset of spatially-explicit marine fisheries catches. This approach enabled us to assign exploitation status across a 0.5° latitude/longitude ocean grid system and trace the change in their status over the 56-year time period. This result highlights the global scale expansion in marine fisheries, from the coastal waters off North Atlantic and West Pacific to the waters in the Southern Hemisphere and into the high seas. The southward expansion of fisheries occurred at a rate of almost one degree latitude per year, with the greatest period of expansion occurring in the 1980s and early 1990s. By the mid 1990s, a third of the world's ocean, and two-thirds of continental shelves, were exploited at a level where PPR of fisheries exceed 10% of PP, leaving only unproductive waters of high seas, and relatively inaccessible waters in the Arctic and Antarctic as the last remaining ‘frontiers.’ The growth in marine fisheries catches for more than half a century was only made possible through exploitation of new fishing grounds. Their rapidly diminishing number indicates a global limit to growth and highlights the urgent need for a transition to sustainable fishing through reduction of PPR. 
 
 Funding: This research was funded by the Pew Charitable Trusts (via fundings to the Sea Around Us project), National Geographic Society and the Waitt Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. 
 
 Copyright: © 2010 Swartz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 
 
 However, the global impact of fishing on the ecosystem, which includes species across the food chain from herbivores to top predators, cannot be fully assessed by the study of single-species catches. A more appropriate way of quantifying the expansion of and limits to fisheries is using the primary production required (PPR) to sustain catches – a metric of the ecological footprint of fishing. As defined by Pauly and Christensen [15] , PPR allows direct comparison of the primary production required to generate a catch of a given (group of) species in a given time period (here: 1 year), and hence it allows for (indirect) comparisons between the catches of very different species of fish and invertebrates. Further, when the PPR of a given catch taken at a given locale is expressed as a fraction or percent of the primary production observed at that locale, we can use arbitrary thresholds of this fraction to define this locale as ‘exploited’, i.e., drawn into the scope of fisheries. Here we used different levels of “% PPR” (i.e., percentage of the primary production of the cells of a map of the global ocean) to quantify the expansion of fisheries since 1950 and extract the dominant patterns of this expansion. 
 
 This decrease occurred, essentially, because the rate at which new fish stocks (for example of deep sea fish; [11] ) were accessed, from the late 1980s on, failed to compensate for the rate at which ‘traditional’ stocks were depleted. Moreover, the number of new stocks has been decreasing linearly over time [12] . This can be shown, e.g., using catch-status plots for different Large Marine Ecosystems [13] , which account for the state of thousands of single-species stocks [14] . 
 
 The aftermath of the First and Second World War saw both a recovery of these stocks, and an increase in the sophistication of industrial vessels; which were equipped with diesel engine and increasingly sophisticated eco-locating equipment, and with refrigeration, enabling longer and longer trips. In 1950, the Food & Agriculture Organization of the United Nations [7] began issuing annual compendia of global fisheries statistics [8] which documented that global catches increased throughout the 1960s and 1970s, though the rate at which this increase proceeded slowly declined. In the late 1980s, global catches ceased to increase and peaked at 90 million t when account is taken of systematic over reporting of catches by China [9] . The slow decrease of about half million t per year which then ensued has not been reversed since [7] , and is not likely to ever be [10] . 
 
 There is a wide realization that fisheries, similar to agriculture on land [1] , has a tremendous impact on marine ecosystems and on the biodiversity embedded therein [2] , [3] . This applies particularly to modern industrial fisheries, here defined as fisheries using craft powered by fossil fuel, which began in about 1880, when the first British steam trawlers were deployed. These quickly depleted the coastal population of flatfish and other bottom fish they were targeting, and they had to move offshore, gradually expanding into the entire northeastern Atlantic [4] , [5] . A similar development was mirrored off New England, and along the coast of Japan, where local fish populations, already much reduced by operation conducted off sail-powered vessels (e.g., [6] ), were strongly depleted. 
 
 Results and Discussion 
 
 Most of the ecological footprint of fishing concentrated on the waters off the industrialized countries of North America and Europe, and off Japan in 1950, and have expanded to cover most of the world's productive waters by 2005. Figure 1 presents the spatial patterns of the proportion of the local primary production required to sustain the catch, for 1950 and 2005. These figures clearly demonstrate the expansion of fisheries, particularly of areas where the proportion of primary production exploited equal or exceed 30% (in red). The expansion is accompanied by the nearly five-fold increase in catch, from 19 million tonnes in 1950 (equivalent to 9 billion tonnes [wet weight] of primary production) to 87 million tonnes in 2005 (equivalent to 45 billion tonnes [wet weight] of primary production). In 2005, the footprint of one tonne of catch was, on average, 556 tonnes of PP (wet weight). 
 
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 larger image ( ) TIFF original image ( ) Download: Figure 1. Primary production required (PPR) to sustain global marine fisheries landings expressed as percentage of local primary production (PP). Estimates of PPR, PP and PPR/PP computed per 0.5° latitude/longitude ocean cells. PPR estimates based on the Sea Around Us catch database (www.seaaroundus.org) and PP estimates derived from SeaWiFS's global ocean colour satellite data. The maps represent total annual landings for 1950 (top) and 2005 (bottom). Note that PP estimates are static and derived from the synoptic observation for 1998. doi:10.1371/journal.pone.0015143.g001 
 
 Some patterns in Figure 1 should be noted. First, the exploitation levels off the coast of East Africa in 2005 are likely to be underestimated due to underrepresentation of unreported catches in the region [16], [17]. Moreover, waters off the Pacific Island countries are known fishing grounds for tuna fisheries and reported to have a relatively high level of illegal and unreported catch [18]. 
 
 The rate of expansion can be illustrated by estimating the size of fishing grounds that become ‘newly exploited’ in each year. The 1980s to the mid 1990s were the period of greatest expansion (Figure 2), which corresponds to the period during which world catches began to stagnate, peaked and declined [9]. Similarly, Figure 3, which shows the cumulative area of the ocean that was exploited by fisheries based on multiple exploitation thresholds (10, 20 and 30%), highlights this accelerated expansion of the 1980s and the early 1990s. Comparison between the world ocean (left) and the continental shelves (coastal waters down to 200 m depth; right) shows that the accelerated expansion during this period was driven primarily through expansion into the open ocean. It should be noted that for both continental shelves and the world ocean, the pace of expansion slows down, because most commercially viable regions have been expanded into, leaving areas furthest away from fishing ports such as in the South Atlantic and the shelves off Antarctica. 
 
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 larger image ( ) TIFF original image ( ) Download: Figure 3. Time series of areas exploited by marine fisheries (1950–2005) expressed a percentage of the total ocean area. ‘Area exploited’ defined as regions where primary production required (PPR) to sustain reported fisheries landings exceeds the threshold percentage of local primary production (PP). Results based on three exploitation thresholds (10%, 20% and 30%), and for all marine areas (left) and continental shelf areas (i.e., up to 200 m in depth, right) are presented. doi:10.1371/journal.pone.0015143.g003 
 
 Figure 4 summarizes the direction of this expansion by presenting the time series of the proportion of the world ocean that has come to be exploited across latitudinal gradients. The figure shows that, even in the 1950s, the majority of the ocean surface in the North was already exploited and that, over time, an increasing proportion of the ocean in the South has become exploited. The waters near the poles are either covered in ice or away from fishing ports, rendering them unattractive, for now, to commercial exploitation. 
 
 Finally, Figure 5 quantifies the rate of this southward expansion by presenting the distributions of the areas of new exploitation for each decade. This expansion in marine fisheries was increasingly reliant on new fishing grounds in the South, with the means of these new fishing grounds shifting southward, on average, by about 0.8 degree per year. The northward deviations of the means from the regression line in the 2000s suggest that the expansion has run its course. This possibility is further confirmed the reduction in the size of newly exploited areas (i.e., areas under the curve) from 1990s to 2000s. 
 
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 larger image ( ) TIFF original image ( ) Download: Figure 5. Newly exploited area (103 km2) for each latitude class, averaged over each decade. Newly exploited area defined as ocean cells where primary production required to sustain fisheries catch exceeds the threshold percentage of primary production. Results based on three exploitation thresholds (10%, 20% and 30%) are presented. Black dots at the base of each histogram represent the mean latitude of the distribution. The dots for each exploitation threshold are fitted with a linear regression; jointly, they suggest the southward expansion of 0.7 to 0.9 degree per year. doi:10.1371/journal.pone.0015143.g005 
 
 The expansion of the fisheries presented here can be viewed as an ecological footprint of the world fisheries. Ecological footprints are measured as the ratio between the productivity of the ecosystem and human consumption [19]. The standardization of fisheries catches into PPR enables footprints of various fisheries to be compared against the primary productivity of marine ecosystems. 
 
 The complexity and variability of fisheries and the marine ecosystems within which they are embedded therein make it difficult to define an across-the-board exploitation threshold of sustainability. An analysis of PPR across various Exclusive Economic Zones (EEZs) and Large Marine Ecosystems (LMEs) showed that fisheries exploitation can range from 1% in the Australian EEZ up to 80% in Icelandic EEZ, with varying impacts on the ecosystem ([20], and see contributions in [13]). The larger values are extraordinarily high compared with the 23.8% of potential net primary productivity humans appropriate on land [21]. 
 
 Using PPR to calculate the loss of secondary production due to fishing, Coll et al. [22] showed that total catch per capita from Large Marine Ecosystems is at least twice the value estimated to ensure fishing at moderate sustainable levels. Chassot et al. [23] estimated that the primary production appropriated by current global fisheries is 17–112% higher than that appropriated by sustainable fisheries. In this study we also suggest that relatively low thresholds (between 10% and 30%) of PPR are sufficient to induce, and thus also track, expansion of fisheries. 
 
 These thresholds are more significant than they may seem, because the ecological impact of fishing depends on how much of the local primary production is available to sustain seafood production. For instance, only 41% of coastal phytoplankton is consumed by herbivores and moves up the food chain [24]. Therefore, the values of % PPR presented in this study are only a fraction of the actual proportion of primary production that is available for seafood production. In cases where fisheries capture more than 30% of local primary production (Figure 1), they may be capturing most of the PP available to fisheries. Further work is required to determine how much PP we are ‘overcapturing’. In other words, we need to estimate the proportion of primary production can be sustainably removed each year without compromising ecosystem integrity. 
 
 For our analysis, we assumed primary production to be constant over the study period, due to incomplete temporal coverage in the SeaWiFS dataset. While the level of primary production may have declined over the past 50 years concomitant with an observed reduction in the global chlorophyll concentration [25], the spatial patterns are thought to have been consistent at global scale [26]. The spatial patterns of expansion observed in our study should thus be independent of changes in global primary productivity, as evident by the similarities in the expansion patterns observed using three exploitation thresholds. However, our estimates of %PPR are likely conservative, and the footprint of fishing larger than reported here. 
 
 Nevertheless, the comparison with increase in agricultural production is startling. Tilman [1] observed that doubling of world agricultural production over the 35-year period, from 1961 to 1995, was accompanied by an increase of only 10% of the surface under cultivation. Over the same period, marine fisheries, which underwent a comparable 2.4-fold increase in catch (34 million tonnes to 83 million tonnes in catch weight or 17 billion tonnes to 44 billion tonnes in PPR, wet weight), required a nearly 4-fold increase in exploited area (when a 10% exploitation level is used as threshold). 
 
 Our results demonstrate that the growth in the world's marine fisheries over the past 56 years was driven through a sequential exploitation of new fishing grounds. Fisheries now cover a majority of the world's ocean, with areas of low productivity and distant waters as the final remaining ‘frontiers’. The decline of newly exploited areas since the late 1990s, which corresponds to a decline in global landings [7], implies that the era of great expansion has come to an end. With a limited room for expansion, and excessive appropriation of primary production in many regions, the only way toward sustainability of global fisheries goes through reduction of PPR.
– Global overfishing might be much worse than previously thought, Discovery reports. A new study finds that UN figures have vastly understated the problem and that yearly fish hauls are declining three times faster than realized. According to the study, the UN—using numbers from the Food and Agriculture Organization—stated that global fishing peaked in 1996 at 86 million metric tons, but the researchers say it was actually closer to 130 million metric tons. Since then, the study claims the total amount of fish caught has declined by 1.2 million metric tons per year—not 0.4 million metric tons as the UN had said, the Guardian reports. “Our results indicate that the decline is very strong and is not due to countries fishing less," study author Daniel Pauly says. "It is due to countries having fished too much and having exhausted one fishery after another.” The study, which was published Tuesday in Nature Communications, is based on a decade of work by 400 researchers around the world. The numbers used by the UN come from the self-reporting of more than 200 countries and territories, and governments might not always be inclined to give accurate fishing counts, notes the Guardian. Researchers undertook a "Herculean task" to get more accurate counts for the years from 1950 to 2010, says one professor not involved with the study. “The world is withdrawing from a joint bank account of fish without knowing what has been withdrawn or the remaining balance,” Pauly tells Discovery. And while the Food and Agriculture Organization disputes the study's new numbers, it does agree with its conclusion that countries need to improve their reporting, according to Science. (One particularly devastating technique: bombing fish out of the water.)