Dr. Deborah Robertson-Andersson; Carmen Haripursad & Nadia Padayachee

Aquacultures balancing act1) Close the food gap

2) Support economic development

3) Reduce Environmental impact

Bondad-Reantaso AASA 2015

(Transgenada, 2012)

(Gentlemangourmet, 2010)

Irrigated agriculture represents the bulk of the

demand for water in many countries (Wharton, 2013)

(Wikipedia,1999)(Wikipedia,1999)

The Blue revolution

“The South African landscape is littered with failed aquaculture projects”

Tom Hecht AASA 2013

Reasons for failure

Ineffective institutional arrangements

Lack of good

quality feed and technical advice

Poor market infrastructure

Central planning instead of

private sector

initiative

Aquaponics

1) 2 honors students

2) R3500

3) Build 2 aquaponics systems each

4) USE locally sourced materials within 25 km of your

house!!!

5) Get your honors degrees

Aims1) Determine if plant growth in goldfish and koi fish

systems were significantly different

2) Determine if LED light was different to sunlight on crop

production

3) Determine whether aquaponics can be considered a

form of leap frog technology

4) Evaluate the costs and benefits

Methods:

Experimental design

Experimental design and construction of the aquaponic systems

Methods

New number of leaves produced,

root production,

shoot production,

mass production,

average leaf size,

relative plant growth

mean number of mortalities

were recorded for each plant type.

Nitrate concentration & pH measured end of each harvest

Plants:

Lettuce, Tomato, Spinach,

Coriander, mint & watercress

Fish – Koi (Cyprinus carpio L.)

Gold fish (Carassius auratus L.)

(Ecofilms, 2011)

Results

Round 1

27 27

14 12

1

56

3

0

5

10

15

20

25

30

35

Nu

mb

er

of

mo

rta

liti

es

Plant typeLettuce Spinach Mint Watercress

GoldfishKoifish

*

Mean mortalities for each plant type

t =2.828

df = 70

p = 0.047

Goldfish Koi fish

Results

Round 2

Figure 4: Relative plant growth for each plant type

t = 2.885

df = 70

p = 0.005

Goldfish Koi fish

*

0,03 0,04

0,09

0,13

0,19

0,39

0,260,28

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

0,45

0,5

Lettuce Spinach Mint Watercress

Re

lati

ve

pla

nt

gro

wth

(g

/da

y)

Plant types

Goldfish

Koi fish

Results

Round 3

Figure 5: Root: shoot ratio for each plant type

8 3 30 2855 50

10989

18 18

33 32

127167

8795

0

50

100

150

200

250

Ro

ot:

Sh

oo

t ra

tio

(m

m)

Plant type Lettuce Spinach Mint Watercress

Koifish root length (mm)

Koifish shoot length (mm)

Goldfish root length (mm)

Goldfish shoot length (mm)

Goldfish Koi fish

Results

Round 4

Goldfish system Koi fish system

Nitrates (*)

pH

80 mg/l (±4.4)

7.5 (±0.48)

110 mg/l (±12.9)

7.8 (±0.81)

Table 1: The nitrates concentration (n = 6) and pH levels (n = 6) in the goldfish and koi fish systems

Nitrate significance : t = 4.176, df = 5, p = 0.006

Goldfish Koi fish

And the winner is……

Koi fish

LED vs. Sunlight……

Round 1 – 9

Number of leaves

Average leaf size

Shoot length

Root length

Leaf area ratio

Dry plant mass

Relative growth rate

NO SIGNIFICANT DIFFERENCE

Results

Round 1 – 7

Wet plant massMortality

0

2

4

6

8

10

12

14

16

Spinach Tomato Lettuce

We

t p

lan

t m

ass

(g)

Type of plant

Sunlight

LED

The effect of LED versus sunlight on the

marginal means of the wet plant mass for

each plant species

The mean mortality of harvests for each species

under sunlight and LED light

Spinach (T-test: df = 70, t = 2.277, p = 0.026)Tomato (T-test: df = 70, t = 2.194, p = 0.031)

Coriander (T-test: df = 70, t = 3.245, p = 0.000)

03

0

34

03

5

35

Spinach Tomato Lettuce Coriander

0

5

10

15

20

25

30

35

40

Type of plant

Me

an m

ort

alit

y h

arve

stS

(N =

36

)

Sunlight

LED

High mortality of coriander

Insufficient nutrient supply by fish

Possibly potassium which has a

significant relationship with other

nutrients such as calcium and

magnesium

Wet plant mass

Increased wet mass of plants

result of many factors such as:

- plants growing environment

- water storage ability

Problems with aquaculture

Aquaculture is similar to the

electric network.

It depends on government

funding and a large quantity

of fries to stock a pond.

Electric stations are interlinked

Leapfrog technology“An approach in which areas with poorly developed technology or economic bases are able to move themselves forward at a rapid

pace through the adoption of modern systems, without going through intermediary steps”

It is the implementation of advanced technology in areas where prior technology hasn’t been implemented.

e.g. The mobile network.

Telephone stations emitting signals that is received by communication technologies

Ornamental trade is similar

to the the mobile network

Graphs representing all pet stores, hardware stores and nurseries within a

50km radius of the study site

DurbanRichards Bay

90 +

0 +

270 -

180 -

Stores

Nurseries

Growbed materials

Fish products

Electrical products

Plumbing supplies

Research institute

Rhodes University

Government hatchery

Scale

Stores

1 block = 1 km

Research institute

1 block = 50 km

Cost analysis

Items Income

Lettuce

Spinach

Mint

Watercress

Goldfish

Koifish

Total

R648.00

R2944.00

R2640.00

R3780.00

R600.00

R7500.00

18112.00

COST VS. INCOMEItems Expenditure

Nursery

Building equipment

Pipes and plumbing

pH and thermometer

Grow beds and trays

Fish tanks, fish, feed, gravel, nitrate kit

Wood

Electricity cost per annum

Total

R804.00

R615.22

R695.50

R198.80

R666.95

R1457.60

R678.00

R294.24

R5410.31

Payback time of the system (based on income from crop production)

= 11 months and 7 days

Payback time of the system (based on income from fish breeding)

= 5 months

Aquacultures balancing act1) Close the food gap

2) Support economic development

3) Reduce Environmental impact

Bondad-Reantaso AASA 2015

Thank you!

ReferencesAlexandratos, N. (1999). World food and agriculture: outlook for the medium and longer term. Proceedings of the National Academy of Sciences: 96, 5908-5914.

Aquaponicsideasonline (2001-2014) How it works, http://aquaponicsideasonline.com/how-to-care-for-fish-in-an-aquaponic-system Accessed 27 February 2014

Bitsizebio (2000-2014) Brainfood for biologists, http://bitesizebio.com/8046/pseudoreplication-don%E2%80%99t-fall-for-this-simple-statistical-mistake/ Accessed 28 February 2014

Bernstein, S. (2011). Aquaponics Gardening: A step by step guide to raising vegetable and fish together. New Society Publishers, Canada, 24-27.

Bornman, E. (2014). Access to the Internet and Mobile Phones in South Africa: The Results of Longitudinal Studies, 3-4.

Castellani, D., Camargo, A. F. M., & Abimorad, E. G. (2009). Aquaponics: use of the effluent from the secondary nursery of Macrobrachium amazonicum for the production of hydroponic lettuce (Lactuca sativa) and watercress (Rorippa nasturtium aquaticum). Bioikos: 23, 67-75.CCRES (2011-2014) Chinampaaquaponics, http://ccresaquaponics.blogspot.com/2012/06/chinampa-aquaponics.html Accessed 3 March 2014

Diver, S. (2006) Aquaponics – Integration of Hydroponics with Aquaculture. Attra 4-6

Ecofriend (1999-2014) Promoting an eco friendly lifestyle http://www.ecofriend.com/860-mile-wide-ball-water.html Accessed 27 February 2014

Ecofilms (2011-2014) Plants that go crazy in aquaponics, Accessed 28 February 2014

Eskom appliance energy calculator, (1999) http://www.eskom.co.za/sites/idm/Pages/EnergyCalculator, Accessed on 12 October 2014

Farmers weekly, (2009), Retrieved from http://www.farmersweekly.co.za . Accessed on 10 October 2014

Godfray, H. C. J., Beddington, J. R., Crute, I. R., Haddad, L., Lawrence, D., Muir, J. F., & Toulmin, C. (2010). Food security: the challenge of feeding 9 billion people. Science: 327, 812-818.

Gentlemangourmet. (2010-2014) Food for thought, http://gentlemangourmet.com/tag/travels-2/ Accessed 27 February 2014

Hopkins, G. & Goodwin, C. (2011) Living Architecture, CSIRO Publishing, Australia

Hurlbert, S.H., 1984. Pseudoreplication and the design of ecological field experiments. Ecological Monographs 54(2):187-211

Masters, G., Norgrove, L., 2009. Climate change and invasive alien species. CABI Protection paper, pp 1-36.

Powell, W. (2013). Aquaponic Gardening Demystified: The Art Of Growing Crops And Raising Fish. Speedy Publishing LLC.of Agricultural Economics, 77(4), 853-864.

Rosegrant, M. W., & Ringler, C. (1997). World food markets into the 21st century: environmental and resource constraints and policies. Australian Journal of Agricultural and Resource Economics, 41(3), 401-428.

The future we want (2012-2014) No water, no future, http://www.dropbydrop.eu/36680 Accessed 28 February 2014

Transgenada (2012-2014) Foodupgraded, http://www.transgenada.com/2012/bill-gates-of-it-renown-says-biotechnology-is-critical-to-our-survival/ Accessed 28 February 2014

Wharton, J. (2013) Academic Encounters (Second Edition), Cambridge University Press, New York

Wikipedia (1999-2014) Irrigation, http://en.wikipedia.org/wiki/Irrigation Accessed 28 February 2014

Rogers, P. & Leal, S. (2010) Running out of water, Palgrave Macmillan, New York