Global commercial exploitation of Gelidium resources
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By Rui Santos (algae-U. Algarve) & Ricardo Melo (CO-FCUL) - Oral presentation to the 19th International Seaweed Symposium - 2007 - Kobe, Japan
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Global commercial exploitation of Gelidium resources
- 1. Global commercial exploitation of Gelidium resources Centro de Ciências do Mar do Algarve Rui Santos and Ricardo Melo
- 2. 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
- 3. Objectives • To analyse all available time series on Gelidium landings 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
- 4. • 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 amansii G. 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 Landings(tdw) 4000 3000 2000 1000 5000 Source: Prof. Daisuke Fujita, Tokyo University of Marine Science and Technology, Japan Japan
- 5. 0 1000 2000 3000 4000 5000 6000 7000 1950 1953 1956 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 Year Landings(tdw) • Higher absolute values of landings (up to about 6500 t) • Same pattern of constant decrease of landings at the present Gelidium amansii G. elegans Japan (FAO data)
- 6. 0 1000 2000 3000 4000 5000 6000 7000 1946 1949 19521955 19581961 19641967 1970 19771980 19831986 19891995 1998 2002 2005 Year Landings(tdw) 0 100 200 300 400 500 600 700 800 900 1000 Agarproduction(t) Gelidium Agar Spain http://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%
- 7. 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 Weight(tdw) 0 200 400 600 800 1000 1200 1400 Agarexport(t) Gelidium landings Gelidium export Agar 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 corneum Photo (A. Santolaria)
- 8. 0 500 1000 1500 2000 2500 3000 3500 4000 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 2006 Year Landings(tdw) 0 100 200 300 400 500 600 700 800 900 Agarproduction(t) Gelidium Agar 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 %
- 9. 0 500 1000 1500 2000 2500 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 Year Landings(tdw) Portugal Azores islands Pterocladiella capillacea • Landings at highest levels during 1970s: export to mainland • Low levels through 1980s and 1990s • Collapse during 2000s
- 10. 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 Landings(tdw) 0 20 40 60 80 100 120 140 160 180 Agarexport(t) Gelidium Agar 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
- 11. Chile Gelidium lingulatum G. chilense G. 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” 0 200 400 600 800 1000 1200 1400 1600 1800 1980s 1991 1993 1995 1997 1999 2001 2003 2005 Year Landings(tdw) 0 500 1000 1500 2000 2500 Agarexport(t) Gelidium Agar
- 12. 0 50 100 150 200 250 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Year Landings(tdw) South Africa Gelidium pristoides G. abbottiorum G. 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
- 13. Global assessment of Gelidium resources 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 1980s 1990s 2000s Decades Landings(tdw) South Africa Chile Mexico Indonesia Portugal Japan South Korea Morocco Spain • 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
- 14. 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
- 15. 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 CPUE (Kgman -1 hour -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.
- 16. Thank you! Centro de Ciências do Mar do Algarve