fish water productivity: a sinner's view
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Presented at the Pre-Forum BFP meeting, 7-8 November, 2008 in Addis Ababa, EthiopiaTRANSCRIPT
Fish water productivity
A sinner’s view
Some observations
0
1000
2000
3000
4000
5000
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
GVP, million $
Crop Livestock Inland fisheries
0
500
1000
1500
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003Year
GVP, million $
Crop Livestock Fisheries Fish - high estimate
0
1000
2000
3000
4000
5000
1995 1996 1997 1998 1999 2000 2001 2002 2003Year
GVP, million $
Crop Livestock Fish low estimate
0
200
400
600
800
1,000
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
GVP, million $
Crop Livestock Fish low estimate
Fish stocks almost certainly under-estimated – even
in Mekong
Total Thai fish , Mekong agriculture
Cambodia
Thailand
Laos
Vietnam
Simple story
Andean0.0
0.5
1.0
0.00 0.50 1.00 1.50 2.00
Rain / ETpot
ET / ET pot
Capacity limit
Suppy limit
Ganges
Mekong
Sao Francisco
Volta
Yellow River
NileLimpopo
IndusKarkeh
Fish
Livestock
Crops
Irrigation
M ekong
1,19 5 bcm
Ganges
1,167 bcm
K a r kh eh
2 1 , 4 0 2 mcm
Irrigation ET
Yellow
384 bcm
Rainfed cropsLimpopo
229 bcm
Grassland ET
Indus
865 bcm
Net runoff
Nile
2,042 bcm
Sa o F r a n c i s c o
6 2 2 b c m
Capture fisheries
likely to be
important in wet
basins
Aquaculture
elsewhere –
markets permitting
Threats to fish stocks
• More flow more fish - Dai fishery in Tonle Sap river
• Expect flow changes (dams) to lead to decline in
yield
Valued-addingSmoking fish, a women activity
Aquaculture more likely to meet expanding demand
Capture Aquaculture
‘water productivity’
• What we know
• What we don’t know
we know…
• …case studies showing fish CAN be important
• Where present, fish provide special support. Triple systems in Africa– Fish, crops, cattle
• Fish under-reported in statistics
• 84%of global catch from 20 countries– 10 Asia, 7 Africa
• Top 20 countries per capita fish catch– 4 in Asia (but includes Cambodia), 13 in Africa
We don’t know
• If the concept of Wprod is useful for fish
– More akin to livestock
• Basic data on fish stocks
– Consumption data vs recorded catch
• How many people depend on fish
• What happens to fish stocks if hydrology
changes
• What alternatives exist if fish stock is
damaged
Are fish likely to be important?
Suggested structure
• To evaluate ‘water productivity’
– Aquaculture that uses water abstracted
• The most straightforward
– Aquaculture integrated into livestock / cropping systems
• More complex trade-offs
– Capture fisheries
• Mainly about evaluating the over-looked
Some sources
• Some papers
– Martin van Brakel et al. 2008. Water Productivity of fisheries.
– Maya Rajasekharan 2008. Towards an understanding of fisheries water productivity
– David Blake. 2006.The Songkhram River wetlands - A critical floodplain ecosystem of the Lower Mekong Basin
– Chris Bene and Richard Friend. 2008. Water, poverty and inland fisheries: Some lessons from Africa and Asia.