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Systematic Distortions in World Fisheries Catch Trends

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Abstract and Figures

Over 75% of the world marine fisheries catch (over 80 million tonnes per year) is sold on international markets, in contrast to other food commodities (such as rice). At present, only one institution, the Food and Agriculture Organization of the United Nations (FAO) maintains global fisheries statistics. As an intergovernmental organization, however, FAO must generally rely on the statistics provided by member countries, even if it is doubtful that these correspond to reality. Here we show that misreporting by countries with large fisheries, combined with the large and widely fluctuating catch of species such as the Peruvian anchoveta, can cause globally spurious trends. Such trends influence unwise investment decisions by firms in the fishing sector and by banks, and prevent the effective management of international fisheries.
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18. Peteanu, L. A., Shoenlein, R. W.,Wang, Q., Mathies, R. A. & Shank, C. V.The ®rst step in vision occurs
in femtoseconds: complete blue and red spectral studies. Proc. Natl Acad. Sci. USA 90, 11762 ±11766
(1993).
19. Shoenlein, R. W., Peteanu, L. A., Wang, Q., Mathies, R. A. & Shank, C. V. Femtosecond dynamics of
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(1993).
20. Mathies, R. A., Brito Cruz, C. H., Pollard, W. T.& Shank, C. V. Direct observation of the femtosecond
excited-state cis-trans isomerization in bacteriorhodopsin. Science 240, 777± 779 (1988).
21. Atkinson, G. H., Brack, T. L., Blanchard, D. & Rumbles, G. Picosecond time-resolved resonance
Raman spectroscopy of the initial trans to cis isomerization in the bacteriorhodopsin photocycle.
Chem. Phys. 131, 1±15 (1989).
22. van den Berg, R., Jang, D. J., Bitting, H. C. & El-Sayed, M. A. Subpicosecondresonance Raman spectra
of the early intermediates in the photocycle of bacteriorhodopsin. Biophys. J. 58, 135± 141 (1990).
23. Doig, S. J., Reid, P. J. & Mathies, R. A. Picosecond time-resolved resonance Raman spectroscopy of
bacteriorhodopsin J, K, and KL intermediates. J. Phys. Chem. 95, 6372±6379 (1991).
24. Diller, R. et al. Femtosecond time-resolved infrared laser study of the J-K transition of bacterio-
rhodopsin. Chem. Phys. Lett. 241, 109± 115 (1995).
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to 12-fs resonant impulsive Raman spectroscopy of bacteriorhodopsin. J. Phys. Chem. 96, 6147± 6158
(1992).
26. Bardeen, C. J., Wang, Q. & Shank, C. V. Femtosecond chirped pulse excitation of vibrational wave
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dopsin. J. Chem. Phys. 79, 603±613 (1983).
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associated with ultrafast geometrical relaxation in polydiacetylene induced by sub-5-fs pulses. Chem.
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Acknowledgements
We thank J. Watson and M. Murao for careful reading of the manuscript. This work was
partially supported by the Research for the Future program run by the Japan Society for
Promotion of Science (T.K.), the Special Coordination Funds (``Molecular Sensors for
Aero-Thermodynamic Research''; H.O.) and Scienti®c Research (H.O.) of the Ministry of
Education, Culture, Sports, Science and Technology.
Correspondence and requests for materials should be addressed to T.K.
(e-mail: kobayashi@phys.s.u-tokyo.ac.jp).
letters to nature
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Systematic distortions in world
®sheries catch trends
Reg Watson*& Daniel Pauly*
*Fisheries Centre, 2204 Main Mall, University of British Columbia, Vancouver,
British Columbia V6T 1Z4, Canada
..............................................................................................................................................
Over 75% of the world marine ®sheries catch (over 80 million
tonnes per year) is sold on international markets, in contrast to
other food commodities (such as rice)1,2. At present, only one
institution, the Food and Agriculture Organization of the United
Nations (FAO) maintains global ®sheries statistics. As an inter-
governmental organization, however, FAO must generally rely on
the statistics provided by member countries, even if it is doubtful
that these correspond to reality. Here we show that misreporting
by countries with large ®sheries, combined with the large and
widely ¯uctuating catch of species such as the Peruvian anchoveta,
can cause globally spurious trends. Such trends in¯uence unwise
investment decisions by ®rms in the ®shing sector and by
banks, and prevent the effective management of international
®sheries.
World ®sheries catches have greatly increased since 1950, when
the FAO of the United Nations began reporting global ®gures3. The
reported catch increases were greatest in the 1960s, when the
traditional ®shing grounds of the North Atlantic and North Paci®c
became fully exploited, and new ®sheries opened at lower latitudes
and in the Southern Hemisphere. Global catches increased more
slowly after the 1972 collapse of the Peruvian anchoveta ®shery4, the
®rst ®shery collapse that had repercussions on global supply and
prices of ®shmeal (Fig. 1a). Even taking into account the variability
of the anchoveta, global catches were therefore widely expected to
plateau in the 1990s at values of around 80 million tonnes, especially
as this ®gure, combined with estimated discards of 16 ±40 million
tonnes5, matched the global potential estimates published since the
1960s (ref. 6). Yet the global catches reported by the FAO generally
increased through the 1990s, driven largely by catch reports from
China.
These reports appear suspicious for the following three reasons:
(1) The major ®sh populations along the Chinese coast for which
assessments were available had been classi®ed as overexploited
decades ago, and ®shing effort has since continued to climb7,8; (2)
Estimates of catch per unit of effort based on of®cial catch and effor t
statistics were constant in the Yellow, East China and South China
seas from 1980 to 1995 (ref. 9), that is, during a period of
continually increasing ®shing effort and reported catches, and in
contrast to declining abundance estimates based on survey data7; (3)
Re-expressing the of®cially reported catches from Chinese waters on
0
45
50
55
60
65
70
75
80
85
90
1970 1975 1980 1985 1990 1995
Global catch (× 106 tonnes)
Uncorrected
Corrected
Corrected, no anchoveta
El Nino
event
a
˜
2000
0
2
4
6
8
10
12
14
16
18
1970 1975 1980 1985 1990 1995
Chinese catch (× 106 tonnes)
Overall marine
EEZ uncorrected
EEZ corrected
b
Constant catch
mandated
2000
El Nino
events
˜
Figure 1 Time series of global and Chinese marine ®sheries catches (1950 to present).
a, Global reported catch, with and without the highly variable Peruvian anchoveta.
Uncorrected ®gures are from FAO (ref. 3); corrected values were obtained by replacing
FAO ®gures by estimates from b. The response to the 1982± 83 El Nin
Äo/Southern
Oscillation (ENSO) is not visible as anchoveta biomass levels, and hence catches were still
very low from the effect of the previous ENSO in 1972 (ref. 4). b, Reported Chinese
catches (from China's exclusive economic zone (EEZ) and distant water ®sheries)
increased exponentially from the mid-1980s to 1998, when the `zero-growth policy' was
introduced. The corrected values for the Chinese EEZ were estimated from the general
linear model described in the Methods section.
© 2001 Macmillan Magazines Ltd
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a per-area basis leads to catches far higher than would be expected
by comparison with similar areas (in terms of latitude, depth,
primary production) in other parts of the world.
We investigated the third reason in some detail by generating
world ®sheries catch maps on the basis of FAO ®sheries catch
statistics for every year since 1950 (see Fig. 2a for a 1998 example).
A statistical model was used to describe relationships between
oceanographic and other factors, and the mapped catch. Most
high-catch areas of the world were correctly predicted by the
model. These areas typically had very high primary productivity
rates driven by coastal upwellings, like those off Peru, supporting a
large reduction ®shery for the planktivorous anchoveta Engraulis
ringens4. The exception was the waters along the Chinese coast.
Here, the high catches could not be explained by the model using
oceanographic or other factors. Yet the catch statistics provided to
FAO by China have continued to increase from the mid-1980s
until 1998 when, under domestic and international criticism, the
government proclaimed a `zero-growth policy' explicitly stating
that reported catches would remain frozen at their 1998 value
(Fig. 1b)10.
Mapping the difference between expected (that is, modelled)
catches and those mapped from reported statistics showed large
areas along the Chinese coast that had differences greater than
5 tonnes km
-2
year
-1
. Overall, the statistical model for 1999 pre-
dicted a catch of 5.5 million tonnes, against an of®cial report of
10.1 million tonnes (see Fig. 1b for earlier years). Although
China was not the only FAO member country reporting relatively
high catches, their large absolute value strongly affects the global
total.
For a number of obvious reasons, ®shers usually tend to under-
report their catches, and consequently, most countries can be
presumed to under-report their catches to FAO. Thus we wondered
why China should differ from most other countries in this way. We
believe that explanation lies in China's socialist economy, in which
the state entities that monitor the economy are also given the task of
increasing its output11. Until recently, Chinese of®cials, at all levels,
have tended to be promoted on the basis of production increases
from their areas or production units11. This practice, which origi-
nated with the founding of the People's Republic of China in 1949,
became more widespread since the onset of agricultural reforms
Catch
difference
(tonnes km–2 year–1)
10+
5–10
1–5
< 1
b
a
Catch
(tonnes km–2 year–1)
20+
10–20
5–10
1–5
< 1
Figure 2 Maps used to correct Chinese marine ®sheries catch in Fig. 1b. a, Map of
global catches reported by FAO for 1998, generated by the rule-based algorithm
described in the Methods section. We note the anomalously high values along the
Chinese coast, comparable in intensity (not area covered) to the extremely productive
Peruvian upwelling system. b, Map of differences in southeast and northeast Asia
between the catches reported in aand those predicted by the model described in the
Methods section.
© 2001 Macmillan Magazines Ltd
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that freed the agricultural sector from state directives in the late
1970s (refs 10, 11).
The Chinese central government appears to be well aware of this
problem, and its 1998 `zero-growth policy' was partly intended to
prevent over-reporting. Thus, the of®cial ®sheries catches for 1999±
2000 are precisely the same as in 1998 (Fig. 1b), and will be for the
next few years. Such measures, although well motivated, do not
inspire con®dence in of®cial statistics, past or present.
The substitution of the more realistic estimated series of Chinese
catches into the FAO ®sheries statistics led to global catch estimates
which, although ¯uctuating, have tended to decline by 0.36 million
tonnes year
-1
since 1988 (rather than increase by 0.33 million
tonnes year
-1
, as suggested by the uncorrected data). The global
downward trend becomes clearer when the catches of a single
species, the Peruvian anchoveta, which is known to be affected by
El Nin
Äo/Southern Oscillation events, is subtracted (see Fig. 1a). In
this case, a signi®cant (P,0:01), and so far undocumented down-
ward trend of 0.66 million tonnes year
-1
becomes apparent for all
other species and ®sheries. This is consistent with other accounts of
worldwide declines of ®sheries12,13.
Ironically, it is likely that, at the lowest levels (individual ®shers),
catches are under-reported in China as elsewhere in the world. The
production targets caused these reports to be exaggerated. At some
times these two distortions may perhaps have cancelled each other
out, and an accurate report of catches may have been submitted to
FAO. Since the early 1990s, however, the exaggerations have appar-
ently far exceeded any initial under-reporting.
The greatest impact of in¯ated global catch statistics is the
complacency that it engenders. There seems little need for public
concern, or intervention by international agencies, if the world's
®sheries are keeping pace with people's needs. If, however, as the
adjusted ®gures demonstrate, the catches of world ®sheries are in
general decline, then there is a clear need to act. The oceans should
continue to provide for a substantial portion of the world's protein
needs. The present trends of over®shing, wide-scale disruption of
coastal habitats and the rapid expansion of non-sustainable
aquaculture enterprises14, however, threaten the world's food
security. M
Methods
Data processing involved a disaggregation of global ®sheries catch statistics ®rstly into
detailed taxonomic groups, and then into ®ne-scale spatial cells (a half-degree of latitude
by a half-degree of longitude), using a variety of databases and systematic rules15. The
spatially disaggregated catches provided the basis for a general linear model of ®sheries
catches (see below). The model predicted the likely catches in the spatial cells in the
Chinese exclusive economic zone (EEZ), thus providing an estimate of Chinese catches
(including Hong Kong and Macau, but excluding Taiwan).
Data sources
Fisheries catch statistics were provided by the FAO (FishStat3and `Atlas of Tuna and
Bill®sh Catches', http://www.fao.org/®/atlas/tunabill/english/home/htm). The spatial cells
were described by depth (US National Geophysical Data Center), primary productivity
(Joint Research Centre of the European Commission Space Applications InstituteÐ
Marine Environment Unit, http://www.gmes.jrc.it/download/kyoto_prot/glob.marine.pdf),
biogeochemical provinces16, the presence of ice (US National Snow and Ice Data Center,
http://www.nsidc.org), surface temperature (NOAA's Marine Atlas, http://www.nodc.noaa.
gov/OC5/data_woa.html), and an upwelling index calculated for each cell by multiplying
negative deviations in surface temperature (from the averagefor that latitude and ocean) by
the primary productivity in that cell. Fishing access rights were determined using maps of
the exclusive economic zones (EEZ) of coastal states17 and a database of ®shing access
agreements18.
Taxonomic disaggregation
The ®sheries statistics of several nations commonly include a large fraction of catches in
`miscellaneous' categories. Chinese catches so reported were disaggregated on the basis of
the breakdown provided by its two nearest maritime neighbours with detailed marine
®sheries statistics (Taiwan and South Korea)15. Assigning catches to lower taxa allowed the
use of biological information in the spatial disaggregation process.
Spatial disaggregation
A database of the global distribution of commercial ®sheries species was developed using
information from a variety of sources including the FAO,FishBase19 and experts on various
resource species or groups. Some distributions were speci®c; others provided depth or
latitudinal limits, or simple presence/absence data. The spatial disaggregation process
determined the intersection set of spatial cells within the broad statistical area for which
the statistics were provided to FAO,the global distri bution of the reported species, and the
cells to which the reporting nation had access through ®shing agreements15. The reported
catch tonnage was then proportioned within this set of cells.
Catch predictions
A general linear model was developed in the software package S-Plus20 . The model relates
log ®sheries catch (in tonnes km
-2
year
-1
) for each cell (the dependent variable) to depth,
primary productivity, ice cover, surface temperature, latitude, distance from shore,
upwelling index (the continuous predictor variables), 33 oceanic biogeochemical
provinces and one global coastal `biome'16 including most of the area covered by the
world's EEZs, including China's (the categorical predictor variables). Fishing effort was
not used in the prediction and catches were assumed to be generally close to their
maximum biologically sustainable limits. The additive and variance stabilizing transfor-
mation (AVAS) routine of S-Plus20 was used to identify transformations ensuring linearity
between the dependent and explanatory variables, and the model was then used to predict
the catch from each spatial cell. Those from Chinese waters were combined, then
compared with the catches obtained from the rule-based spatial disaggregation described
above.
Trend analyses
The estimates of recent trends of global catch were estimated by linear regression of catch
versus year, for the period from 1988 (highest catches, anchoveta excluded) to 1999 (last
year with FAO data), for uncorrected global marine catches, global marine catches
adjusted for Chinese over-reporting, and adjusted catches minus the catch of Peruvian
anchoveta.
Received 30 July; accepted 28 September 2001.
1. Food and Agriculture Organization. Fisheries TradeFlow (1995 ±1997) 330 (Fisheries Information,
Data and Statistics Unit, FAO Fisheries Circular No. 961, Rome, 2000).
2. IRRI. in Rice Almanac (ed. Maclean, J.) 2nd edn, 31±37 (International Rice Research Institute, Los
Ban
Äos, Philippines, 1997).
3. Food and Agriculture Organization. FISHSTAT Plus. Universal software for ®shery statistical time
series. Version 2.3. (Fisheries Department, Fishery Information, Data and Statistics Unit, Rome,
2000).
4. Muck, P. in The Peruvian Upwelling Ecosystem: Dynamics and Interactions (eds Pauly D., Muck, P.,
Mendo, J.& Tsukayama, I.) 386±403 (International Centre for Living Aquatic Resource Management,
Makati, Philippines, 1989).
5. Alverson, D.L., Freeberg, M., Pope, J. & Murawski, S. A Global Assessment of Fisheries By-catch and
Discards: A Summary Overview. 1±233 (FAO Fisheries Technical Paper 339, Rome, 1994).
6. Pauly, D. One hundred million tonnes of ®sh, and ®sheries research. Fish. Res. 25, 25±38
(1996).
7. Tang, Q. in Biomass Yields and Geography of Large Marine Ecosystems (eds Sherman, K. & Alexander,
L. M.) 7±35 (AAAS Selected Symp. 111, Westview, Boulder, 1989).
8. Huang, B. & Walters, C. J. Cohort analysis and population dynamics of large yellow croaker in the
China Sea. N. Am. J. Fish. Man. 3, 295± 305 (1983).
9. Chen,W. Marine Resources: Their Status of Exploitation and Management in the People's Republic of
China. 60 (FAO Fisheries Circular No. 950, Rome, 1999).
10. Pang, L. & Pauly, D. in The Marine Fisheries of China: Development and Reported Catches (authors
Watson, R., Pang, L. & Pauly, D.) 1±27 (Fisheries Centre Research Report 9(2), Univ. British
Colombia, Vancouver, 2001); also at http://®sheries.ubc.ca/Reports/china.pdf.
11. Kwong, L. The Political Economy of Corruption in China 1±75 (M. E. Sharpe, Armonk, New York,
1997).
12. Botsford, L. W., Castilla, J. C. & Peterson, C. H. The management of ®sheries and marine ecosystems.
Science 277, 509± 515 (1997).
13. Pauly, D., Christensen, V., Dalsgaard, J., Froese, R. & Torres, F. C. Jr Fishing down marine food webs.
Science 279, 860± 863 (1998).
14. Naylor, R. L. et al. Effect of aquaculture on world ®sh supplies. Nature 405, 1017± 1024 (2000).
15. Watson, R., Gelchu, A. & Pauly, D.in Fisheries Impacts on North Atlantic Ecosystems: Catch, Effort, and
National/Regional Data Sets. (eds Zeller, D., Watson, R. & Pauly, D.) (Fisheries Centre Research
Report, Univ. British Colombia, Vancouver, in the press).
16. Longhurst, A. Ecological Geography of the Sea 77 ±85 (Academic, San Diego, 1998).
17. Veridian Information Solutions 2000. Global Maritime Boundaries Database CD. (Veridian, Fairfax,
Virginia, 2000).
18. Food and Agriculture Organization. Fisheries Agreements Register (FARISIS). 1±4 (Committee on
Fisheries, 23rd session, Rome, 1999; COFI/pp/Inf.9E, 1998).
19. Froese, R. & Pauly, D. (eds) FishBase 2000. Concepts, design and data sources. ((International Centre
for Living Aquatic Resource Management, Los Ban
Äos, Philippines, 2000); 4CD-ROMs; updates on
http://www.®shbase.org.
20. S-Plus Guide to Statistics. Vol. 1 (Data Analysis Product Division, MathSoft, Seattle, 2000).
Acknowledgements
We thank V. Christensen for the upwelling index, and A. Gelchu for the species
distribution shape ®les used here. We also thank our colleagues in the `Sea Around Us'
Project. This work was supported by the Pew Charitable Trusts through the `Sea Around
Us' Project, Fisheries Centre, University of British Columbia. D.P. also acknowledges
support from the National Science and Engineering Council of Canada.
Correspondence and requests for materials should be addressed to R.W.
(e-mail: r.watson@®sheries.ubc.ca).
© 2001 Macmillan Magazines Ltd
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環團找碴 ±2錯誤一籮筐?
【聯合晚報記者劉開元/台北報導】 2010.03.03 06:05 am
台灣首部氣候變遷紀錄片「正負2C」推出後,引起廣大回響,但今天有環保團體和台大教
授來「找碴」,仔細檢視紀錄片內容後,發現有不少錯誤資訊,例如片中說「北極冰融,海平
面上升」,學者應是「南極冰融才會造成海平面上升」;並呼籲教育部不該把這部紀錄片送給
學校當教材,否則老師怎麼教?
由資深媒體人陳文茜監製的紀錄片「正負2C」,首映會號召工商大老、五院院長共同推
薦,部分人士並建議應將該片送給全台各學校放送。
環保團體今天對「正負2C」的批評相當辛辣。以台大大氣科學系教授徐光蓉為首的多名環
保人士仔細觀看過全片,發現該片除大量採用公共電視紀錄外,對氣候變遷問題避重就輕,內
容有不少錯誤,甚至認為「僅適合茶餘飯後閒聊之用」。徐光蓉表示,「正負2C」片名本
身就可能引起誤會。國際間多數國家同意增溫不應該超過攝氏2度,但沒有「負」的問題。
該片提到「台灣人口密度世界第二高」,徐光蓉直指是「錯誤的資訊」,查國際人口資料20
09年中人口密度排名在台灣前面的依序為: 摩納哥、澳門、新加坡、香港、巴林、馬爾他、孟
加拉、馬爾地夫、Channel Islands、巴貝多、巴勒斯坦等11地。她也對片中所指「台灣土地
侵蝕率每年2%」的數據存疑,依此推論,50年不到,台灣就會侵蝕殆盡,那台灣有400年歷
史,原住民更可追溯兩三千年,又是怎麼回事?
徐光蓉列舉該片出現「科學上的錯誤」包括,第五段549秒處「如果北極冰融,海平面上
升…」,應該是南極冰融非北極。依據大氣科學原理,北極冰融不會改變海平面高度,片中所
指冰融造成海平面上升,徐光蓉認為「違反阿基米德原理」。「該片若是教材,老師該怎麼
教?」
該片所述「台灣氣溫上升攝氏一度, 降雨增加100%」,徐光蓉認為過於武斷,她也抨擊該片
不當的誇耀「學術性」。該片學者顧問Stephen Schneider,擔任IPCC三個工作小組中第二
個小組(WGII,衝擊、適應與脆弱性)的主要撰寫人,並非工作小組召集人。2007年諾貝爾和
平獎由高爾與IPCC這單位共同獲得,由印度籍主席Rajendra Pachauri代表IPCC領獎。Sch
neider教授有其學術地位,但非該片製作所述的諾貝爾獎得主。
當教材?教部:須經嚴謹審查
【記者王彩鸝/台北報導】
教育部環保小組表示,任何影片如果要成為教學補充教材,都必須經過學者專家從嚴謹的角度
1/ 2環團找碴 ±2錯誤一籮筐? | 綜合 | 國內要聞 | 聯合新聞網
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來審查,確保內容正確無誤,才可當作教學使用。至於會不會收錄「正負2C」?環保小組
的態度傾向保留,強調「教育必須傳遞正確的知識」。
延伸閱讀》
網評/誰的「正負二度C?
網評/正負兩度C,一場群體的偽善!
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... та викиди [8][9][10]. Глобальне виробництво риби було обмеженим і прогнозувалося наприкінці 1960-х років, коли вилови становили лише близько половини від початкового рівня [11,12]. ...
... Таким чином, пік вилову досяг середини 1990-х років. Відтоді він впав до 9 % або нижче цього рівня [9,20], незважаючи на збільшення промислових зусиль за той самий період [21]. Дані про вилов та зусилля є середніми для більшої частини Африки, Азії та Латинської Америки. ...
... This paper contributes to several strands of the literature. First, it contributes to studies focusing on the compliance behavior of fishers (e.g., Cabral et al., 2018;Diekert et al., 2021;Drupp et al., 2019;FAO, 2018;Nøstbakken, 2008;Vollaard and Kastoryano, 2023;Watson and Pauly, 2001). The state of common-pool resources is of particular interest for a sustainable stock management. ...
... However, the open access to these resources and costly monitoring render it hard to assess the true level of compliance. Previous studies, for example, focus on fishers' truthtelling to regulators (Drupp et al., 2019) or the validity of catch records reported to international organizations (FAO, 2018;Watson and Pauly, 2001). What we know from these studies is that fishers, but also regulators, tend to misreport private information on their actual catches. ...
... Official fisheries landings data has often limited accuracy (Pauly and Froese, 2012) and false statistics may systematically distort world landing trends, whether over-reported (Watson and Pauly, 2001) or underreported (Pauly and Maclean, 2003). These data may also lead to an underestimation of the total commercial harvests because they do not include discarded, subsistence, recreational and non-reported catches. ...
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The present study aims to describe Greek overseas fisheries from the beginning of the sector in the mid-20th century up to today. The Greek overseas fisheries expanded, from the northern African countries to the Atlantic and Indian Ocean, peaking in the 1970s. However, starting in the 1990s, the sector exhibited a sharp decline in landings and active vessels, which was caused by several issues, such as the increased territorial restrictions, high operational costs, unorganized market structures, and insufficient fish processing facilities. The historical evolution of the Greek overseas fisheries high- lights the need for improved market integration and smart policy interventions.
... Globally, we are eating more aquatic foods than ever before with current statistics suggesting per capita consumption is at 20.2 kg/year, over double the consumption 50 years ago (FAO 2022). Consumption growth, facilitated and encouraged by fast growing populations, rising incomes, seafood commoditisation, and the promotion of marine products for their health properties (Belton et al. 2020;Rood and Schechter 2007;Thurstan and Roberts 2014), in conjunction with mismanagement of fisheries, has led to widespread declines and collapses of marine fish stocks (Mullon et al. 2005;Thurstan and Roberts 2014;Watson and Pauly 2001). In many countries, local capture fisheries are no longer able to satiate domestic markets (D'Odorico et al. 2014;Godfray et al. 2010;Taylor et al. 2007). ...
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Seafood markets have become increasingly internationalised over the course of the twentieth century, induced by expanding footprints of fishing fleets, improved communication and transport infrastructure, and trade agreements. We compiled archival UK seafood import data from UK Government, SEAFISH and FAO sources to track the expansion of the UK’s global reach for seafood products from 1900 to 2020. UK domestic fisheries landings declined from the 1970s following overexploitation and regulatory reforms, leading to a growing dependence on fish catches outside national waters and the international seafood trade-network. The volume of reported seafood imports increased by 6.4-fold from 1900 to 2020, overtaking domestic landings in 1985, with the species composition of these imports reflecting the palette of UK consumers, i.e., for the ‘big 5’ of cod, haddock, salmon, tuna and prawns, alongside agri/aquaculture industry demands for fishmeals/oils. The number of reported countries from which the UK imported seafood increased from five in 1900 to eighty-nine in 2020, covering all continents. The average distance seafood was imported increased by between 18 and 32%, from 2980 km (1900) to ~ 3520–3940 km (2020) (UK Government and SEAFISH data respectively), demonstrating the increasing geographic spread of UK demand. These results accentuate the need for stringent domestic fisheries management to recover local fish stocks, consumer diversification beyond the ‘big 5’, and for improved collaborative international fisheries governance to mitigate the potential for serial depletion of popular food fish. Graphical abstract
... The coastal waters of Balochistan, which stretch 734 km and represent 76.2% of the country's total coastline, are rich in marine biodiversity and natural resources [14]. However, despite this ecological wealth, marine fishery data for the region are unreliable due to challenges such as bycatch, illegal fishing, and the exclusion of small-scale fisheries [15,16]. The dominant fishing methods in Pakistan's marine sector include gillnets and trawls, primarily targeting demersal species like croakers, snappers, and groupers [17]. ...
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The sustainable exploitation of fishery resources in Pakistan was assessed using the catch-based Monte Carlo method (CMSY) and the length-based Bayesian biomass (LBB) method to evaluate the data-limited fishery of the Spangled Emperor, Lethrinus nebulosus. CMSY relies on catch data, resilience parameters, and quantitative stock status metrics, while LBB exclusively uses length–frequency (LF) data for stock assessments. This study utilized twenty-two years of catch–effort and LF data from 7230 fish along the Balochistan coastline in Pakistan. The study revealed that the relative biomass of the exploited stock, with a B/BMSY ratio of 0.557, indicates significant depletion. The relative exploitation rate (F/FMSY = 2.47) confirms that the stock is being severely overfished. The discrepancy between the optimal length at first capture (Lc_opt = 43.1 cm) and the length at first capture (Lc = 38.8 cm) further proves the overexploitation of L. nebulosus. The convergence of findings from both methodologies strengthens the reliability of stock status estimates. By integrating diverse data types and analytical frameworks, this study provides valuable insights into the sustainability of L. nebulosus populations. This dual approach not only underscores the importance of varied data sources but also informs management strategies for effective fisheries conservation, contributing to a deeper understanding of resource dynamics along the Balochistan coast of Pakistan.
... Since there is the possibility of China's misreporting (Watson and Pauly, 2001), for further analysis, I use the data with the exclusion of China's reported catches (including China does not change the results). ...
Preprint
I address the question of the fluctuations in fishery landings. Using the fishery statistics time-series collected by the Food and Agriculture Organization of the United Nations since the early 1950s, I here analyze fishing activities and find two scaling features of capture fisheries production: (i) the standard deviation of growth rate of the domestically landed catches decays as a power-law function of country landings with an exponent of value 0.15; (ii) the average number of fishers in a country scales to the 0.7 power of country landings. I show how these socio-ecological patterns may be related, yielding a scaling relation between these exponents. The predicted scaling relation implies that the width of the annual per capita growth-rate distribution scales to the 0.2 power of country landings, i.e. annual fluctuations in per capita landed catches increase with increased per capita catches in highly producing countries. Beside the scaling behavior, I report that fluctuations in the annual domestic landings have increased in the last 30 years, while the mean of the annual growth rate declined significantly after 1972.
Article
Modern stock assessment models used to provide management advice on sustainable catches rely on unbiased catch data. Distortion of this data, intentional or not, may increase the uncertainty in the stock perception, jeopardize the assessment of marine resources, and compromise their sustainable management with negative ecological and socio-economic effects. In this study, we apply an analysis of anomalous numbers based on the Newcomb–Benford law (NBL) to test for fisheries catch misreporting. We focus on the Swedish small pelagic fisheries targeting herring and sprat in the Baltic Sea, which are known to be highly problematic due to the pronounced mixing of the two species in their catches and the existence of potential incentives for misreporting. The analyses also include fishery-independent data from international scientific surveys, which are used as standards for the interpretation of the anomalies in the commercial catch data. We demonstrate that data from two Baltic fishery independent surveys conformed to the NBL, while Swedish commercial catch data recorded at sea (logbooks) and onshore (landing declarations) did not, indicating inaccurate reporting of commercial catches. While non-conformity to the NBL may not be considered as proof of misreporting, and to determine the intentionality of misreporting, if any, goes beyond the scope of the paper, we discuss the possible reasons for the observed deviations from the model and recommend the application of this method for quality control of fishery data. Further research (i.e. testing new tools both for detection and estimation of misreporting) should be carried on this fishery with the aim of improving the accuracy of the reported catches. Furthermore, we open the discussion to whether the management should rely on less accurate but more spatially resolved or more accurate but spatially unresolved commercial data. The application of the NBL presented in this study can be readily implemented to other stocks and fishery as a supporting tool to investigate potential misreporting and contribute to improve our understanding of self-reported fisheries data.
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Mangroves are a critical habitat that provide a suite of ecosystem services and support livelihoods. Here we undertook a global analysis to model the density and abundance of 37 commercially important juvenile fish and juvenile and resident invertebrates that are known to extensively use mangroves, by fitting expert-identified drivers of density to fish and invertebrate density data from published field studies. The numerical model predicted high densities throughout parts of Southeast and South Asia, the northern coast of South America, the Red Sea, and the Caribbean and Central America. Application of our model globally estimates that mangroves support an annual abundance of over 700 billion juvenile fish and invertebrates. While abundance at the early life-history stage does not directly equate to potential economic or biomass gains, this estimate indicates the critical role of mangroves globally in supporting fish and fisheries, and further builds the case for their conservation and restoration.
Article
The Black Sea salmon is one of the endemic species of the Black Sea. Its natural distribution area is the Black Sea and many rivers that feed the Black Sea and the Sea of Azov. While its non-migratory forms are found in small streams and river branches that flow into the Black Sea, its anadromous forms are found in large streams and rivers that flow into the Black Sea. In recent years, as a result of anthropological effects, the anadromous forms in particular are facing the danger of extinction in the streams where the species is distributed. The confusion regarding its naming, which is important in the hunting ban list, which is effective in the decrease of the natural population, continues today. However, the names Black Sea salmon, Salmo labrax, Black Sea salmon are still current. In Turkey, the synonyms Black Sea salmon, sea trout, sea trout and red spotted trout are widely used. The first known study on the production of the species under culture conditions was initiated in the 1920s in a hatchery established in the Abkhazia region for the purpose of fish breeding. In Turkey, the stock status of sea trout was investigated with the study initiated with FAO support in 1988, and preliminary studies were conducted for facility locations for culture production. Following this study, breeding stock was created with individuals collected from the natural environment starting in 1998, many culture characteristics were determined, they were cultured, used for fish breeding purposes and introduced to the private sector. Today, commercial aquaculture production continues only in Turkey among the countries neighboring the Black Sea. This study was prepared to better understand the Black Sea salmon, which is consumed with pleasure by the communities in its natural distribution area, to understand the changing ecosystem for the species and to contribute to the spread of its commercial production.
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Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts. On balance, global aquaculture production still adds to world fish supplies; however, if the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.
Article
Cohort analysis is used to reconstruct the population dynamics of the large yellow croaker (Pseudosciaena crocea (Richardson)) in the China Sea, using age-composition and catch data from 1957 to 1979. A precondition for cohort analysis is that natural mortality M and terminal catch- ability coefficient q be known. These are estimated from age-composition data for two relatively stable periods with widely different exploitation rates. Cohort analysis suggested the virginal stock size of large yellow croaker was about 730,000 t. The biomass remained at a high stable level (about 480,000 t) until the middle 1960’s; the stock then decreased rapidly because of increasing fishing effort. Recruitment apparently increased at first as the stock declined, but there are signs of decreased recruitment at the current low stock size. The present stock is about 200,000 t, the lowest on record. Different recovery and management strategies were evaluated by computer simulation. The maximum equilibrium yield is probably 95,000-100,000 t, associated with an equilibrium biomass of 390,000 t. considering environmental effects on recruitment, the yield is likely to fluctuate between 70,000 and 130,000 t. To maintain the maximum average yield, the fishing effort should be equivalent to approximately the present annual fishing capacity of 1,000 pairs of 60- horsepower, paired trawlers in the Zhowshon district. About 15 years will be needed for the stock to recover to optimum equilibrium biomass if the optimum long-term effort is maintained.
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Exceptionally clear and well-written chapters provide engaging discussions of the methods of accessing, generating, and analyzing social science data, using methods ranging from reflexive historical analysis to critical ethnography. Reflecting on their own research experiences, the contributors offer an inside, applied perspective on how research topics, evidence, and methods intertwine to produce knowledge in the social sciences.
Conference Paper
Picosecond resonance Raman spectroscopy has been used to obtain structural information on the primary photointermediates of bacteriorhodopsin. A synchronously pumped dye laser was amplified at 50 Hz to produce a probe pulse at 589 nm. A second, spectrally distinct, pump pulse at 550 nm was generated by amplification of a 10 nm portion of a continuum produced from the probe pulse. This apparatus was used to record spectra of the J, K, and KL intermediates. The J spectrum exhibits strong hydrogen out-of-plane (HOOP) intensity and the fingerprint region consists of a broad series of lines centered at 1180 cm-1. By 3 ps, K has formed and the relative HOOP intensity decreases while the fingerprint collapses to a single mode at 1190 cm-1, characteristic of a 13-cis chromophore. These results argue that J contains a highly twisted chromophore which relaxes upon conversion to K and that isomerization is complete within 3 ps. Between 3 ps and 3.7 ns there is a resurgence in HOOP intensity and the ethylenic frequency rises from 1518 to 1521 cm-1 indicating the conversion of K to KL.
Article
The resonance Raman (RR) spectra in the fingerprint region (1100–1300 cm−1) are reported for the initial, picosecond interval of the bacteriorhodopsin (BR) photocycle during which the J-625 and K-590 intermediates are formed. These are the first RR features assigned to J-625 while the RR bands assignable to K-590 alone are clarified with respect to previous studies. The assignment of RR features to J-625 and K-590 is based on the results of two-laser, picosecond time-resolved resonance Raman (PTR3) experiments designed to separate RR bands of K-590 from other species. The instrumental design underlying PTR3 experiments and the associated advantages for analyzing time-resolved data are described. The PTR3 data in the fingerprint region suggest that neither J-625 nor K-590 contain all-trans retinal and therefore, establish that the primary BR photocycle event involves a configurational change in the retinal chromophore. The RR fingerprint bands assignable to J-625 and K-590, however, differ from one another indicating that the two intermediates do not contain retinal in the same configurational or conformational form and that a second change in retinal structure occurs over the initial 10 ps of the photocycle. The identification of either intermediate in terms of an absolute configuration (e.g., 13-cis retinal) or conformation remains unresolved.
Article
Resonance Raman spectroscopy has been used to obtain structural and kinetic information on the primary photointermediates of bacteriorhodopsin with 3-ps time resolution. A synchronously pumped dye laser was amplified at 50 Hz to produce a probe pulse at 589 nm while a second, spectrally distinct, pump pulse at 550 nm was generated by amplification of a 10-nm portion of a continuum produced from the probe pulse. This apparatus was used to record Stokes Raman spectra of the photoproduct from 0 ps to 13 ns as well as anti-Stokes spectra from 0 to 10 ps. At 0 ps, the Stokes spectrum, assigned to J, has strong hydrogen out-of-plane (HOOP) intensity at 1,000 and 956 cm{sup {minus}1}, the fingerprint region consists of a broad band of lines from 1,155 to 1,200 cm{sup {minus}1}, and the ethylenic line is found at 1,518 cm{sup {minus}1}. By 3 ps the relative HOOP intensity drops to its lowest value and the fingerprint collapses to a single strong mode at 1,189 cm{sup {minus}1}, while the ethylenic remains at 1,518 cm{sup {minus}1}. The lifetime of the initially strong anti-Stokes scattering is {approximately}2.5 ps, indicating that the J {yields} K transition is due, in large part, to vibrational cooling of the chromophore. The authors conclude that the chromophore in J is highly twisted and thermally excited but that it cools and conformationally relaxes to a more planar 13-cis chromophore within 3 ps to form K. Between 3 and 40 ps there is a resurgence in Stokes HOOP intensity which remains large and nearly constant thereafter and the ethylenic frequency shifts from 1,518 to 1,521 cm{sup {minus}1} within 200 ps. These changes are assigned to the conversion of K to a more twisted and bluer-absorbing KL species between 20 and 100 ps which must be caused by an isomerization-induced protein conformational change.