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by the FAO Fisheries Department

A recent scientific article in Nature¹ indicated that China’s marine capture fishery production for 1995-1999 has been overstated in Chinese statistics submitted to and published by FAO. The paper states that a consequence of this is that global marine capture fishery production - excluding Peruvian anchoveta - has probably been declining since 1988 rather than remaining fairly constant as indicated by the statistics. According to the authors from the University of British Columbia (UBC), this would have led to understating the degradation of world fisheries and wrong policy and investment decisions. The issue has been subsequently taken up in a number of newspapers and web media including The Economist². While usefully drawing attention of the wider public on the importance of reliable statistics for fisheries management and monitoring, the articles also reflected a number of misconceptions about: (1) FAO’s understanding of Chinese statistics; (2) FAO’s role in global fisheries statistics; and (3) the possible consequences of an over-estimate of China’s fisheries production on global fisheries management advice, policy and contribution to food security. Clarifications are provided below.

It is not the first time that scientists report the "finding" that China's fishery statistics overestimate production. In fact, several Chinese scientists have previously referred to the problem. FAO has been concerned about China’s agriculture and fisheries statistics for several years and has been working with China to rectify these. Following the first national agricultural census in China, undertaken with the collaboration of FAO in 1997, statistics for meat production were revised downward by about 25%. On land cultivation differences between census and regular time series are as wide as 37%. Data on cereal stocks in China maintained by FAO have also been revised.

About six years ago, apparent discrepancies between per caput food fish supply data derived from fish production and trade statistics on the one hand and consumption figures derived from household surveys on the other started to grow. FAO drew this issue to the attention of the responsible Chinese authority, the Bureau of Fisheries (BOF) of the Ministry of Agriculture. Since then several meetings, missions and three national seminars (e.g. FAO, 2001) have been jointly organized. The last one, in April 2001, recognized the problem and proposed follow-up activities to investigate various aspects of the problem as a possible basis for remedial action. FAO has initiated a number of follow-up activities in conjunction with several Chinese institutions, including the establishment of a pilot sample survey data collection scheme for one county in 2002. Further, an assessment will be made of the quantity of unprocessed fish landings which are used for direct feed in aquaculture. The quantities are believed to be very large and, at present, are wrongly assumed to go for human consumption. The problem is therefore known and action is being taken on it.

The analysis undertaken by UBC, using the FAO statistical database, is a comparison of the production-per-unit-area off the Chinese coast, based on official statistics, with that of other countries with similar ecosystem characteristics. At a smaller scale, an analogous procedure was used by FAO many years ago to address a similar problem in an African country. Both analyses required many assumptions and intensive manipulation of uncertain data but are regarded by FAO as a valid additional indication of a likely problem. Maps showing possible statistical anomalies derived from an earlier UBC analysis for the Northwest Pacific were indeed presented by FAO at a workshop in Beijing in April 2001 as an indication of a problem. In the words of FAO staff (Caddy et al., 1998), "the FAO data set can best be used as an indicator of trends and a generator of research hypotheses to be tested by more exact analyses in individual, smaller and homogeneous fishing areas, where it is suggested that production per area estimates be further developed".

Most press news related to the UBC article stated wrongly that FAO can only accept data from the countries without any possibility of checking or improving them. While this would conveniently limit the liability of FAO about any error in the data it publishes, it does not reflect reality. FAO is involved to a varying degree in (a) promoting the collection and use of statistics; (b) producing statistical manuals and software; (c) training statistical officers; (d) developing/upgrading national statistical systems (as was recently the case with many African and Mediterranean countries); (e) facilitating global cooperation and establishing norms in fishery statistics (through the inter-agency Coordinating Working Party on Fishery Statistics); (f) collecting various statistics from countries, regional fishery bodies, international shipping registers, fishing industry (e.g. marketing and trade data); (g) undertaking first-level check on the data received, for internal consistency, species identification or anomalous trends; (h) inquiring with concerned countries about anomalies; (i) publishing statistics on the various aspects of fisheries in yearbooks and on the web and receiving extensive feedback form users. As a result, statistics supplied by national authorities are routinely corrected when mistakes are obvious, when better data are available from regional fishery bodies or when countries agree with FAO estimates. FAO interacts with countries to explore problems and try to resolve them, though the process can be sensitive and slow. When countries are not responsive to FAO inquiries, FAO estimates are applied unilaterally. Occasionally, when countries offer little supportive explanation of suspect statistics, reported statistics are set aside and FAO estimates published. This action too can be sensitive and provocative, but does sometimes spur corrective action. As pointed out elsewhere in this article, China is working with FAO to try to address these issues.

National reports are the main but not the only source of data used by FAO to maintain its fishery statistics database. In cases where data are missing or are considered unreliable, FAO includes estimates based on the best available information from any source, such as regional fishery organizations, project documents, industry magazines, or statistical interpolations. For fleet statistics, FAO cross-checks data submitted by countries with data from other sources, such as international shipping registers. Information of technological progress (affecting fishing capacity) is obtained through groups of experts. International trade statistics are obtained from countries and supplemented through a comprehensive network of regional inter-governmental institutions created by FAO (the GLOBEFISH system).

In the 1990s, FAO completely revised the fishery production statistics time series available, computerizing them back to 1950, filling in missing data, disaggregating data by fishing areas, taking account of political changes (e.g. emergence of new countries), adjusting species identification (as taxonomy evolves), and improving the discrimination between aquaculture and capture fisheries production. The resulting data sets, as used in the UBC study and numerous other analyses, have been made widely available on the web (FishStat +).

Global reviews of the state of stocks elaborated and published by FAO are not based on catch statistics as primary source of information because there are often more direct indicators of the state of resources than the catch. Primary information used is obtained directly from the working groups of the FAO and non-FAO regional fishery organizations (RFOs) and other formal arrangements, scientific literature (scientific journals, theses, etc.), supplemented by information from industry magazines, and fishery-independent information such as trade data. Where RFOs do not exist, such as in the Northwest Pacific, there are bilateral assessment processes (e.g. among China, Japan and Republic of Korea) which can be built upon. Where data do not exist, on discards for instance, estimates are made on a one-off basis (e.g. Alverson et al., 1994), using consultant experts or through dedicated expert consultations. In the areas in which FAO has not yet had the means to work effectively e.g. production from illegal fishing, there is no information at all at global level. However, all such data are only available for certain areas or certain years. The great advantage of FAO’s catch statistics is that they are global in coverage, have complete time series since 1950 and are regularly updated, and so they are used to provide overview trends in fisheries by region (e.g. FAO, 1994) and to provide resource status indicators when other data are lacking (e.g. FAO, 1997).

During the last decade, financial support for the development and maintenance of national fishery statistical systems has decreased sharply in real terms, while statistical requirements have been increasing dramatically for by-catch and discards, fishing capacity, illegal fishing, vessels authorized to fish in the high seas, economic data (costs, revenues, prices, subsidies), employment, management systems, inventories of stocks and fisheries, aquaculture, etc.

Despite FAO’s efforts, the fishery data available are not fully reliable. The outcome is far from perfect in terms of coverage, timeliness, and quality. Data are submitted to FAO often with one or two years of delay. The proportion of catch identified at the level of individual species has tended to decrease with time, and the percentage of "unidentified fish" in the declarations has increased as fisheries diversified and large stocks were depleted. Stock assessment working groups provide a good means for screening catch data, but the frequency of stock assessment in many developing regions has dropped for want of human and financial resources. The general availability of data has not really improved during the last two decades. Statistics from artisanal and subsistence fisheries are still a concern and many key statistics are missing, e.g. economic and social data, discards, fishing capacity. The result is that the general trends are probably reliably reflected by the available statistics as shown by the good relations observed with global development trends or climatic changes (Klyashtorin, 2001) but the annual figures and the assessments involve a certain degree of uncertainty and small changes from year to year are probably not statistically significant.

The FAO Fisheries Department believes that working with the countries is the only way to improve fishery statistics, primarily to meet national needs with regard to food security and fisheries management, but also those of regional fishery bodies and FAO. Without reliable statistics, effective fisheries management and policy-making are impossible, with serious negative implications at the national and regional levels. Unfortunately, the rehabilitation of major national data collection schemes to provide reliable statistics is necessarily a slow process.

It has been argued in the press that the statistical discrepancy has led to wrong signals being sent to governments and industry, wrong policy and investment decisions, and indeed complacency. It will be demonstrated below that this is a result of misunderstanding.

3.1 State of global stocks

It has been argued that the potential error in statistics may have affected the "vision" of the state of stocks. FAO stresses that in order to elaborate its judgement on the global state of stocks, as published for instance in FAO (1997), it uses mainly the results of direct assessments complemented by analysis of catch data. Such assessments are collected from regional fishery body working groups, national centres of excellence, scientific publications, grey literature reports, etc., supplemented by ancillary information. This has led to the publication of time series (Fig. 1 and Fig. 2) as well as cross-sections (Fig. 3) on the state of stocks.

Figure 1: Evolution of the state of world resources 1950-94, based exclusively on statistical trends (from Grainger and Garcia, 1996)

Figure 2: Evolution of the state of stocks, 1974-1999, based mainly on stock assessment results (from Garcia and De Leiva Moreno, 2001)

Figure 3: State of stocks in 1999 (From Garcia and De Leiva Moreno, 2001)

Following a complete overhaul of the FAO fishery production database, two series of analysis were made (Grainger and Garcia, 1996; Garcia and Newton, 1997). The first one (Grainger and Garcia, 1996) was exploratory and surprisingly showed a remarkable coherence between the data and the well-known history of fisheries and yielded, inter alia, a dramatic and unique picture of the progression of overfishing since 1950 (Fig. 1). The second led to the development by FAO of a unique bio-economic model of world fisheries (Garcia and Newton, 1997) which, for the first time, demonstrated: (a) the global overfishing since the 1980s of the most valuable species; (b) the fact that by the mid-1990s the world potential was reached; and (c) that a large amount of subsidies were probably used to maintain the world fishing fleet which operated with an overcapacity of 30-50%. This should demonstrate that, despite any potential error in Chinese production figures, the overall negative trend in global stocks and the poor economic performance of world fisheries has been made sufficiently apparent, described and brought to the attention of FAO members as well as the public at large. As a matter of fact, these conclusions have been very widely quoted by scientists, reproduced in the media and used by all leading NGOs.

Regarding more specifically the Northwest Pacific Region, possible errors in Chinese statistics would only affect the assessment of stocks exploited by China and its neighbours. FAO studied the changes in trend in this area, as well as in the other fishing areas, also from the point of view of the production per shelf area (Caddy et al., 1998) and trophic level (Caddy and Garibaldi, 2000). Caddy et al (1998) documented regional declining trends in production and provided some explanations for them. FAO also published a report by a Chinese scientist (Chen, 1999) which evidenced that many marine resources of China have become seriously over-exploited.

In the Nature article, the authors not only corrected the world catch for the Chinese "error" but also eliminated from it the large anchoveta catch, the reality of which is otherwise not questioned, allegedly because its known fluctuations would "hide" the decline. This arbitrarily aggravates the decrease in production possibly resulting from a Chinese bias in the world database and the resulting "decrease" is presented as a novelty. In reality the problem posed by large stocks of fluctuating pelagic and semi-pelagic species had already been raised by FAO in 1994 (Garcia and Newton, 1997). Subtracting from the total production the catch of the five main oscillating species (anchoveta, Chilean horse mackerel, Japanese and American pilchards and Alaska pollock), most of which are utilized for reduction to feeds, FAO demonstrated that the large, high-value species landings decreased since the early 1980s and that all these species were globally overfished by that time with an overcapacity of 30%. The "news" offered in Nature therefore simply confirms an important information already available for many years from FAO.

It is clear from these analyses that, despite likely errors in the data sets, the main global trends have not been masked, and the most important conclusions have emerged. These findings, together with similar ones emerging at regional and national level, have been the foundation for the governance and institutional changes observed since 1990.

3.2 Food security

It has been argued also that the potential error would throw off the FAO global trends of fish-food supply per caput and contribution of fisheries to food security. Food security depends on supply (production plus imports less exports), availability (trade) and accessibility (buying power). It relates to the total food available (meat and grain included). Because consumers can easily shift between sources of protein and between types of fish depending on these parameters, "fish", whether wild or cultured, is usually taken by FAO as one single commodity. Considering "fish" separately from meat and other food items complicates interpretation. Examining only one source of food fish, whether from inland, marine or aquaculture production, reduces even further the meaning of the information in the food security context. Nonetheless, and until the issue is definitively resolved, the contribution of marine capture fisheries to food security may be looked at in terms of absolute or relative (per caput) terms, with or without the Chinese data included. In absolute terms, the global trends indicate a slight but continued increase when China statistics are included versus a stabilisation since the mid-eighties when they are excluded (Fig.4). In line with the latter, the FAO statement has been that that world supplies from ocean capture fisheries have been "stable". However, in per caput terms, the trend shows a stable supply per caput since the mid-seventies when China statistics are included versus a decline of 2.5 kg per person per year since the mid eighties (from 11.8 kg in 1986 to 9.3 kg in 1999) when they are excluded (the proportion used for human consumption remaining steady at about 72% during the period). The latter indicates that the growth of capture fisheries production of food fish for the world excluding China has not been able to compensate for population growth (+ 23% during the period) and, as reported by FAO (FAO, 2000), this statement holds true even for total food fish production including aquaculture which is playing a growing role in addressing food security requirements and will be essential in meeting future demand. FAO has warned, for example, that "in some countries (e.g. Ghana, Liberia, Malawi) the average diet contained less fish protein in the 1990s than it did in the 1970s" (FAO, 2000). Contrary to allegations in some media reports, FAO has not been "complacent". Despite difficulties with the data, the Organization has correctly stated that food fish production, despite its apparent stability, had not been keeping pace with population growth and has warned that fish protein supply per caput had already declined in some areas.

The uncertainty regarding present and future aquaculture production, environmental impacts, climate change, population growth and quantity and distribution of economic wealth have potentially more impact on future food security at the global level during the next two or three decades than the possible error in Chinese reports. However, if such a bias could be confirmed and corrected, the contribution of the oceans to food security, globally, would have indeed decreased. It should be stressed, however, that contrary to allegations, any over-reporting of China’s fisheries production would have implications for the present protein consumption and future supply projections for China only as China’s food fish exports and imports are small compared to production (although it does import large quantities of fishmeal used for animal feeds and aquaculture and exports are large in absolute terms and growing).

The substantial proportion of the world catch being used for fishmeal (30%, of which, contrary to some press reports, less than one third goes into aquaculture feeds), the unknown but probably substantial quantities used as fresh feed in aquaculture (particularly in China) and the large amount of discards (about 20 million tonnes per year) are also potential reserves of food fish for human consumption, despite the present uncertainty on the rate at which their present destination could be effectively changed. The limiting factor in future might be more the buying power (and poverty) than fish supply.

It may be disconcerting that, despite the growing environmental impacts of aquaculture and overfishing, and taking account of all voluntary or involuntary errors in statistics, the overall contribution of fisheries and aquaculture to food security does not appear significantly threatened in the medium term. The two messages on the state of resources and the state of food security, should, however, not be confused. The poor state of resources should be of serious concern today and should indeed have been corrected during the last two decades. The overall contribution of fisheries and aquaculture to food supplies is not yet a concern. The future availability to the poorest stratum of the world population is a concern because of the increase of external trade and prices. The future quality of seafood is of concern because of growing pollution and inappropriate culture techniques. All these concerns, for the moment and for the near future, are not global and are relevant only at disaggregated (national or sub-national) level, for some production systems, in some areas, and for some strata of the population. FAO has, for instance, warned in SOFIA 2000 (FAO, 2000) that the fish supply per caput in Africa has been declining and will decline even further in the future if African countries cannot better manage their resources and/or increase aquaculture production.

There is no doubt, however, that a global decline in marine catches would have sent an even stronger message to the countries, the public and NGOs than the one already repeatedly sent by the Organization since the early 1990s. The amount, direction, and specifics of the Chinese bias, if any, need to be ascertained. In the meantime, as already done in SOFIA 2000, most relevant FAO analyses will be presented as a precautionary measure separately for China and the rest of the world.

3.3 Impact on policy and planning

In general, fishery resources monitoring and management are undertaken on a national or regional basis (e.g. in the framework of regional fishery bodies). If the statistical errors are real, the direct practical implications for sustainability or food security are mainly for China's fishery resources and, to a lesser extent, for shared resources in the Northwest Pacific region.

Global statistics have been used in FAO’s Committee on Fisheries (COFI) and other global fora. Despite the shortcomings with the data, they have accompanied national efforts for institutional change in FAO, in the Commission for Sustainable Development (CSD) and in the UN General Assembly. The UN Fish Stocks Agreement, the FAO Compliance Agreement, the FAO Code of Conduct and its four International Plans of Action are the result of such action at global level. All of this was based on the recognition of the fisheries problems at the highest levels of government and industry and certainly do not reflect "complacency" on the part of FAO. Operational decisions regarding, for example, private-sector investments, attribution of subsidies, decentralisation of decision-making, and fishing access agreements for distant water fleets, are all taken at national level, based on local considerations and have nothing to do with any global picture given by FAO.

It has been argued, however, that the image given by FAO statistics may "condition" the decision-makers. Hoping that this would be at least partially true, let us then remember that, as fisheries evolved, the FAO messages have been (with the main relevant year in brackets):

• The total potential of marine stocks is about 100 million tonnes, out of which, for practical reasons, about 80 million tonnes only may be caught (1971).
• The new Law of the Sea has not led to the expected improvement in fisheries management and state of stocks and fisheries (1984).
• The proportion of overfished stocks increased about tenfold since 1950 (1994).
• The proportion of overfished stocks increased about threefold since 1974 (2001).
• Global overcapacity was very significant, and subsidies possibly substantially contribute to it (1994).
• Total catch is a misleading indicator of the fisheries state, hiding the progressive degradation of the species composition and extension of overfishing (1994).
• A significant part of the annual harvest is discarded (1994).
• The total world catch has reached its maximum since the early 1990s and fluctuates around 80-85 million tonnes, with a zero annual rate of increase (1994).
• Reducing fishing capacity and harmful subsidies is the priority (2000).
• Monitoring of fisheries and resources needs improvement (2001).
• Ecosystem-based management should be introduced (2001).

These messages represent but a small sample of the global FAO message on fisheries. Based on it, at least partly, member countries brought into force the 1982 Convention on the Law of the Sea (1994) and the UN Fish Stocks Agreement (2001); adopted the FAO Compliance Agreement(1993) and the FAO Code of Conduct for Responsible Fisheries (1995); aligned their national laws with these instruments; adopted and started implementing the precautionary approach; accepted the concept of ecosystem-based fisheries management; adopted four international plans of action (on management of fishing capacity, shark fisheries management, reducing by-catch of seabirds in longline fisheries, illegal/unreported/unregulated fishing) and will consider the possibility of adopting one on improvement of information on status and trends of capture fisheries.

Objective and reliable information on status and trends in fisheries is important because it underpins efforts to promote sustainable fisheries and support the implementation of the Code of Conduct. In particular, status and trends reports are critical for effective policy development, fisheries management, and the monitoring of fish stocks and fisheries, in both biological and economic terms. International concern has been expressed about the way in which status and trends information, of which fishery statistics are a very important part, is being assembled and disseminated. FAO has responded to this challenge and has put in train several activities to address shortcomings with current practice. To this end FAO, inter alia, will convene in 2002 a Technical Consultation on Improving Information on Status and Trends of Capture Fisheries and will continue to work with developing countries to strengthen their capacities in this area. An International Plan of Action (IPOA) on improving information on the status and trends of fisheries could also be developed.

It can be argued that all of these achievements are still to lead to general improvement of the situation and the challenge confronting all is to strengthen political will and commitment, build capacity, mobilise resources and achieve equity. Nevertheless, in spite of these challenges, what has already been achieved in the fisheries sector is considered by most observers as one of the most significant outcomes of UNCED. There is therefore no basis to pretend that an overestimate of Chinese statistics has led FAO Members make mistaken policy decisions. Whether the outcomes of those decisions will match expectations remains to be seen.

Most of the articles that followed the publication of the UBC study in Nature maintained that, by reporting to the world mistaken catch statistics supplied by China, one of the most important fishing nations of the world, FAO had (1) distorted the global image of fisheries; (2) distorted the expectations about the contribution of fisheries to food security, and (3) led to wrong policy and investment guidance and decisions.

The information given above, which is only a small part of that available on the FAO website and other publications, demonstrates that such assertions made in global media were ill-founded. FAO’s message has never been that "the exhaustion of local fishing grounds has been balanced by opening new grounds farther afield" and that "stocks are stable". On the contrary, it has been that of the spreading of over-intensive fishing from the northern to the southern hemisphere and a consistent warning to its members about the consequences for the overall sustainability of the global fishery system. It is not true that the "urgency of the situation" has been masked by distorted statistics. Such urgency transpires from FAO’s analyses and has been accepted by FAO Members as is demonstrated by a number of recently concluded international fishery instruments. One of the key elements leading to such large-scale international normative action was indeed the message of urgency coming out of the FAO statistics. While it is really a minor point in this context, it is not true that "most farmed fish are fed a diet consisting mainly of fish". Herbivorous fish and molluscs account for about 90% of the world aquaculture production

A few citations from the recent overview presented by FAO at the Reykjavik Conference in October 2001 (Garcia and De Leiva Moreno, 2001) illustrate the point. FAO stated that after 50 years of particularly rapid geographical expansion and technical advances, and a several-fold increase in annual harvest, marine fisheries are at a crossroads and that the sustainability of the present fishery system is being questioned as most fishery resources are either overexploited or fully or heavily exploited. It did not emphasise any growth in capture fisheries production. On the contrary, it indicated that reported catch reached about 80 million tonnes in the mid-1980s, oscillating since then around 85 million tonnes, with an annual rate of increase decreasing to almost zero in the 1990s, indicating that, on average, the world oceans have reached their maximal production under the present fishing regime. It further indicated that the global proportion of overfished stocks has kept increasing for the last 25 years, even though the phenomenon may be slowing down. The information confirms the estimates made by FAO in the early 1970s that the global potential for marine fisheries is about 100 million tonnes, of which only 80 million tonnes were probably achievable for practical reasons. It was further stated that the quality of data on the state of the resources and the industry needs to be significantly improved for better monitoring and assessment of management performance and that the information available points unequivocally to an increase of the proportion of overfished stocks and a spreading of overfishing across the entire world ocean.

Regarding food security forecasts, FAO considers food fish from all sources, including aquaculture, because of the reality of fish supplies and markets. FAO stated that "As total marine capture production stagnates, the per caput supply from marine capture fisheries is likely to decrease substantially unless more effective management of capture fisheries and further development of aquaculture can increase production." FAO has stressed the fact that the availability per caput of food from capture fisheries could decrease in the future.

FAO recognizes without any difficulty that (1) fishery statistics and the process of collecting them need substantial improvement (also for aquaculture); (2) distortions introduced voluntarily or not by important producers can distort global figures and may impact on public opinion; (3) global figures have, however, limited operational use for national or local decision-making; and (4) there are substantial uncertainties regarding the future contribution of fisheries to food security. It holds true, however, that long-term progress in data quality can only be achieved through collaboration with national and regional scientific and statistical institutions.

FAO also believes in transparency and is proud to have developed fully-accessible information systems allowing analysts from any side to access and reprocess the data, drawing their own conclusions, complementing FAO’s own analytical capacity.

FAO, unlike popular media, must take a balanced approach to "news" making available statistics, analyses, and issuing warnings in a form and language corresponding to its status and function as inter-governmental organization. It assumes, sometimes too optimistically, that these will be read with objectivity by all sides.

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Caddy, J.F. and L. Garibaldi (2000). Apparent changes in the trophic composition of world marine harvests: the perspective from the FAO capture database. Ocean and Coastal Management, 43(8-9): 615-655

Chen, W. (1999). Marine resources, their status of exploitation and management in the People’s Republic of China. FAO Fish.Circ., (950):60 p.

FAO (1994). World review of highly migratory species and straddling stocks. FAO Fish.Tech.Pap., (337):74 p.

FAO (1997). Review of the state of world fishery resources: Marine fisheries. FAO Fisheries Circular, (920):173 p.

FAO (2000). The state of world fisheries and aquaculture 2000. Rome, FAO, 142 p.

FAO (2001). Proceedings of the National Seminar on the System of Food and Agriculture Statistics in China, Beijing, 23-24 September 1999. Volumes I and II. Field Document No. 2/CHN/3 of Project GCP/RAS/171/JPN, Improvement of Agricultural Statistics in Asia and Pacific Countries. Rome, FAO

Garcia S.M. and I. De Leiva Moreno (2001). Global overview of marine fisheries. Paper presented at the FAO-Iceland Conference on Responsible Fisheries in the Marine Ecosystem, Reykjavik, 1-4 October 2001

Garcia S.M. and C. Newton (1997). Current situation, trends and prospects in worldcapture fisheries. In E.L. Pikitch, D.D. Huppert and M.P. Sissenwine (eds.) Global trends: Fisheries management. American Fisheries Society Symposium, 20. Bethesda, Maryland (USA), pp. 3-27

Grainger R. J.R. and S.M. Garcia (1996). Chronicles of marine fishery landings (1950-1994). Trend analysis and fisheries potential. FAO Fish.Tech.Pap., (359):51 p.

Klyashtorin, L.B. (2001). Climate change and long-term fluctuations of commercial catches: the possibility of forecasting. FAO Fish.Tech.Pap., (410):86 p.