Global commercial exploitation of Gelidium resources
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Transcript of Global commercial exploitation of Gelidium resources
Global commercial exploitation ofGelidium resources
Centro de Ciências do Mar do Algarve
Rui Santos and Ricardo Melo
Data Sources
• It is a difficult task to find statistical data on the seaweed harvest
• We want to thank to the people who helped us in this effort:
Angel Borja, Bernabé Santelices, Daisuke Fujita, I K Chung, Ignacio
Bárbara, José Juanes Jose Rico, Juanman Salinas, Put Ang, Robert
Anderson, Tchema Gorostiaga
• On-line publication of data by governmental institutions, trade associations, FAO statistics
• Harvest landings are presented in metric tonnes dry weight
Centro de Ciências do Mar do Algarve
Objectives
• To analyse all available time series on Gelidiumlandings and on agar production in each country of the world
• To assess the global state of the Gelidium resource exploitation
Centro de Ciências do Mar do Algarve
• Japan is the origin of the use of Gelidium for the extraction of agar.
• Sharp and constant decrease of landings at the present;
overexploitation of harvest beds (Fujita and Notoya, 2003)?
Gelidium amansiiG. elegans
0
5000
10000
15000
20000
25000
1912 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96
2000
Year
Land
ings
(t d
w) 4000
3000
2000
1000
5000 Source: Prof. Daisuke Fujita, Tokyo University of Marine Science and Technology, Japan
Japan
0
1000
2000
3000
4000
5000
6000
7000
1950195319561959196219651968197119741977198019831986198919921995199820012004
Year
Land
ings
(t d
w)
• Higher absolute values of landings (up to about 6500 t)
• Same pattern of constant decrease of landings at the present
Gelidium amansiiG. elegans
Japan(FAO data)
0
1000
2000
3000
4000
5000
6000
7000
194619491952195519581961196419671970197719801983198619891995199820022005
Year
Land
ings
(t d
w)
01002003004005006007008009001000
Aga
r pro
duct
ion
(t)GelidiumAgar
Spainhttp://www.asturiasverde.com/2006octubre/00310algas.htm
Gelidium corneum
• Harvest started during World War II, increased to higher values from 1960s/1990s• Harvest collapsed during 2000s• Agar production showed same pattern as landings to the 1990s; agar yield - 20%
0
2000
4000
6000
8000
10000
12000
14000
16000
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
Year
Wei
ght (
t dw
)
0
200
400
600
800
1000
1200
1400
Aga
r exp
ort (
t)
Gelidium landingsGelidium exportAgar
Morocco
• Annual landings relatively stable during the 1990s; increase during 2000s• Exports increased during the 2000s, mainly to Spain• Agar production showed the same pattern as landings; agar yield - 17%
Gelidium corneumPhoto (A. Santolaria)
0
500
1000
1500
2000
2500
3000
3500
4000
195019541958196219661970197419781982198619901994199820022006
Year
Land
ings
(t d
w)
0
100
200
300
400
500
600
700
800
900
Aga
r pro
duct
ion
(t)
GelidiumAgar
Portugal
Gelidium corneum
• Harvest started during World War II,increased to higher values in 1970s, decreased in the late 1970s and increased again to the 1990s• Harvest collapsed during 2000s; • Agar production showed same pattern as landings to the 1990s• Agar yield during 1970s: 33% (Pterocladiella from Azores isl.);1980s: 13 %
0
500
1000
1500
2000
2500
19651968197119741977198019831986198919921995199820012004
Year
Land
ings
(t d
w)
PortugalAzores islands
Pterocladiella capillacea
• Landings at highest levels during 1970s: export to mainland• Low levels through 1980s and 1990s• Collapse during 2000s
Mexico
0
500
1000
1500
2000
2500
3000
3500
1955
1958
1961
1964
1967
1970
1973
1976
1979
1982
1985
1988
1991
1994
1997
2000
Year
Land
ings
(t d
w)
0
20
40
60
80
100
120
140
160
180
Agar
expo
rt (t)
GelidiumAgar
Gelidium robustum
• Sustained levels around 500 t with one small peak in 1967 and a high peak in 1980-2000
• Agar export data do not show any relation with landings
http://www.cdc.noaa.gov/ENSO/enso.current.html
Source: Centro Regional de Investigación Pesquera - Ensenada B.C. México
Chile
Gelidium lingulatumG. chilenseG. rex
FAO FISHERIES TECHNICAL PAPER - 281
• Landings in the 1980s and early 1990s were around 450 t, increased in the 1990s to
highest values of around 1500 t then decreasing to sustained values of about 500 t
• The lack of relationship between Gelidium landings and agar export clearly indicates
that most of the agar exported from Chile is from Gracilaria species.
Source: B. Santelices; “Anuario Estadístico de Pesca, Servicio Nacional de Pesca (SERNAPESCA), Ministerio de Economia de Chile”
020040060080010001200140016001800
1980s
1991
1993
1995
1997
1999
2001
2003
2005
Year
Land
ings
(t d
w)
0
500
1000
1500
2000
2500
Aga
r exp
ort (
t)
GelidiumAgar
0
50
100
150
200
250
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
Year
Land
ings
(t d
w)
South Africa
Gelidium pristoidesG. abbottiorumG. pteridifolium G. capense
Source: Robert Anderson, Seaweed Unit of Marine and Coastal Management.
• Low, sustained landings around 150 t
• There are no local agar processing companies, agar exported to Japan and Korea
Global assessment of Gelidium resources
02000400060008000
100001200014000160001800020000
1980s 1990s 2000sDecades
Land
ings
(t d
w)
South AfricaChileMexicoIndonesiaPortugalJapanSouth KoreaMoroccoSpain
• Decrease from the 1980s to the 1990s, followed by a recovery during the 2000s• Sustained exploitation in South Africa, Chile, Mexico and South Korea• Exploitaion collapsed in Indonesia, Portugal, Japan, and particularly in Spain• Crashes were compensated by increased exploitation in Morocco
Conclusions
• Global Gelidium exploitation has been
sustained in the last 30 years at about 16000 t
• But is this yield sustainable?
– the resource was maintained during the last 10 years
by the increased landings in Morocco, which
represent 73% of world landings
Overexploitation of Morocco beds?• Up to 1000 boats harvesting (T. Givernaut pers. comm.)• Time series of CPUE may answer this question• Need harvest statistics, particularly data on harvest
effort
0
1
2
3
4
5
6
7
8
9
0 10000 20000 30000 40000 50000 60000 70000
Cumulative yield
CPU
E(K
g m
an-1
hou
r-1)
Santos R, Cristo C and Jesus D (2003). Stock assessment of the agarophyte Gelidium sesquipedale using harvest effort statistics. In Proceedings of the International Seaweed Symposium, Cape Town, 2001. Ed. by Anthony R. Chapman, Robert J. Anderson, Valerie J. Vreeland, and Ian R. Davison, Oxford University Press, New York: 145-150.
Thank you!
Centro de Ciências do Mar do Algarve