Water use efficiency in aquaponics and
alternative production systems
Eugene Moore (PhD student)
Supervisor: Dr James Ward
Co-supervisor: Prof Chris Saint
University of South Australia
Large scale?
• Large start up cost (infrastructure, training)
• Technical systems difficult to operate (simultaneously RAS
hydroponics)
• High maintenance and continuous monitoring
• Closed system means high potential for loss of fish and crop
within a short period of time  rapid and unexpected change
in water quality
• Lack of plant diversity (leafy greens or tomatoes?)
Is it possible to achieve the same water use
efficiency in an alternative system?
Water use efficiency
• What is the water use efficiency (WUE)?
1% ?
10% ?
Source: The Living Ocean
Source: Jamaica Hydroponics Limited
Misinformation and unsubstantiated
claims
Review of systems in literature
using water footprint assessment
Table 1: Standard nutrient compositions of fish, tomato and lettuce varieties (Source: Foodworks
Professional Database, 2013) (Mjourn et al., 2010) (FAO 1989)(USDA 2013)
Product
Edible Biomass
Portion
Energy
Content
Protein
(%)
[kcal/g]
[%]
Fish
37
c
c
0.96
20.0b
Tomatoes
100
0.18
0.9
Lettuce
100a
0.15a
1.4a
A review of systems in the literature
using the water footprint assessment
Table 2: Energy and protein production against water consumption from fish and vegetable yields
of aquaponics systems
Year
Journal
Plant Type
Energy
Protein
[kcal/L]
[g/L]
1978
Lewis et al.
Tomatoes
1.862
0.111
1982
Sutton & Lewis
Tomatoes
3.827
0.234
1984
Watten & Busch
Tomatoes
0.968
0.114
1989
Rakocy et al
Lettuce
3.051
0.340
1995
Quillere et al., (1&2)
Tomatoes
1.840
0.144
Lettuce
0.676
0.088
Tomatoes
6.030
0.650
1997
McMurtry et al
2006
Lennard & Leonard
Lettuce
3.138
0.333
2008
Al-Hafedh et al.
Lettuce
2.582
0.308
2.664
0.258
Aquaponics Average
The water footprint assessment
Hoekstra et al., (2011) - The water footprint assessment manual
Fish feed water use (2.2m3/kg)
(Verdegem et al., 2006)
GREEN WATER
BLUE WATER
FEED
WUE : conventional systems vs aquaponics
Table 3: Associated water use of conventional food production adapted from source, (Mekonnen &
Hoekstra, 2012)
Energy
[kcal/L]
Protein
[g/L]
Sugar crops
1.45
0.000
Vegetables
0.75
0.038
Starchy roots
2.13
0.032
Fruits
0.48
0.006
Cereals
1.96
0.048
Oil crops
1.24
0.063
Pulses
0.84
0.053
Nuts
0.28
0.007
Milk
0.55
0.032
Eggs
0.44
0.034
Chicken meat
0.33
0.029
Butter
1.39
0.000
Pig meat
0.47
0.018
Sheep or goat meat
0.24
0.016
Bovine meat
0.10
0.009
Aquaponics
Aquaponics (2.2)
2.664
0.568
0.258
0.050
Product
Aquaponics – food energy production
Energy [kcal/L]
2.5
2
1.5
1
0.5
0
Energy [kcal/L]
Aquaponics – protein production
Protein [g/L]
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
Protein [g/L]
Conclusions from review
• Relative to conventional production systems, the water
footprint assessment method shows aquaponics to be:
– moderately water efficient producer of food energy
– water efficient producer of protein
• Aquaponics:
0.568 kcal/L
0.050 g (protein)/L
Can this be achieve in a one-way flow, soil based system?
Aquaponics
Aquaponics
Integrated agriculture and aquaculture system
Water balance:
Mass balance:
Integrated agriculture and aquaculture system
Water balance:
Mass balance:
Integrated agriculture and aquaculture system
Water balance:
Mass balance:
References
Al-Hafedh, Y.S., Aftab, A. & Beltagi, M.S., 2008. Food Production and Water Conservation in a Recirculating Aquaponic System in Saudi Arabia at
Different Ratios of Fish Feed to Plants. Journal Of The World Aquaculture Society, 39(4), pp.510–520.
Hoekstra, A.Y., Chapagain, A.K., Aldaya, M.M. & Mekonnen, M.M., 2011. The water footprint assessment manual: Setting the global standard,
Earthscan, London, UK.
Lennard, W. A. and B. V. Leonard. 2006. A comparison of three different hydroponic sub-systems (gravel bed, floating and nutrient film technique) in
an aquaponic test system. Aquaculture International 14:539–550
Lewis, W.M., Yopp, J.H., Schramm, H.L. and Brandenburg, A.M. 1978. Use of hydroponics to maintain quality of recirculated water in a fish culture system.
Transactions of the American Fish Society 197: 92–99.
McMurtry, M.R., Sanders, D.C., Cure, J.D., Hodson, R.G., Haning, B.C. & St. Amand, P.C. 1997. Efficiency of water use of an integrated fish/vegetable co-culture
system. Journal of the World Aquaculture Society,28, pp. 420–428.
Mekonnen, M.M & Hoekstra, A.Y., 2012. A global assessment of the water footprint of farm animal products. Ecosystems 15(3), pp.401-415
Quillere, I., Marie, D., Roux, L., Gosse,F. & Morot-Gaudry, J.F., 1993. An artificial productive ecosystem based on a fish / bacteria / plant association .
1 . Design and management. Agriculture, Ecosystems & Environment, 47, pp.13–30.
Quillere, I., Roux, L., Marie, D., Roux, Y., Gosse, F. and Morot-Gaudry, J.F., 1995. An artificial productive ecosystem based on a fish / bacteria / plant
association . 2 . Performance. Agriculture, Ecosystems & Environment, 53, pp.19–30.
Rakocy, J.E. 1989. Vegetable hydroponics and fish culture: a productive interphase. World Aquaculture 20: 42–47
Sutton, R.J. & Lewis, W.M., 1982. Further Observations on a Fish Production System that Incorporates Hydroponically Grown Plants Agitator. The
Progressive Fish-Culturist, 44(1), pp.55–59.
Verdegem, M.C.J., Bosma, R.H. & Verreth, J. a. J., 2006. Reducing Water Use for Animal Production through Aquaculture. International Journal of
Water Resources Development, 22(1), pp.101–113.
Watten, J.B. & Busch, R.L., 1984. Tropical production of tilapia. Aquaculture, Elsevier Science Publishers, 41, pp.271–283.
Timmons, M.B. & Ebeling, J.M., 2010. Recirculating Aquaculture, 2nd Edition. Cayuga Aqua Ventures, Ithaca, NY
Questions?