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


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


• 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!
