INTEGRATED SEAWEED/ABALONE MULTITROPHIC INTEGRATED SEAWEED/ABALONE MULTITROPHIC RECIRCULATING AQUACULTURE (IMTA) IN SOUTH AFRICA: RECIRCULATING AQUACULTURE (IMTA) IN SOUTH AFRICA:

BALANCING THE BALANCE SHEETS, ENVIROMENT AND BALANCING THE BALANCE SHEETS, ENVIROMENT AND COMMERCE COMMERCE

INTEGRATED SEAWEED/ABALONE MULTITROPHIC INTEGRATED SEAWEED/ABALONE MULTITROPHIC RECIRCULATING AQUACULTURE (IMTA) IN SOUTH AFRICA: RECIRCULATING AQUACULTURE (IMTA) IN SOUTH AFRICA:

BALANCING THE BALANCE SHEETS, ENVIROMENT AND BALANCING THE BALANCE SHEETS, ENVIROMENT AND COMMERCE COMMERCE

Deborah V. Robertson-Andersson1, Ana M. Nobre2, Amir Neori3, Kishan Sanker6, Gavin Maneveldt1,

Max Troell4,5, Christina Halling5 and John J. Bolton6

1 The Department of Biodiversity and Conservation Biology Department, University of the Western Cape, Bellville, South Africa.

2 IMAR, Faculty of Sciences and Technology/UNL. Caparica, Portugal. 3 Israel Oceanographic and Limnological Research, National Centre for

Mariculture, Israel.4 Beijer Institute, Stockholm, Sweden.

5 Department of Systems Ecology, Stockholm University, Stockholm, Sweden.

6 Botany Department, University of Cape Town, South Africa.

Deborah V. Robertson-Andersson1, Ana M. Nobre2, Amir Neori3, Kishan Sanker6, Gavin Maneveldt1,

Max Troell4,5, Christina Halling5 and John J. Bolton6

1 The Department of Biodiversity and Conservation Biology Department, University of the Western Cape, Bellville, South Africa.

2 IMAR, Faculty of Sciences and Technology/UNL. Caparica, Portugal. 3 Israel Oceanographic and Limnological Research, National Centre for

Mariculture, Israel.4 Beijer Institute, Stockholm, Sweden.

5 Department of Systems Ecology, Stockholm University, Stockholm, Sweden.

6 Botany Department, University of Cape Town, South Africa.

How to convince an abalone farmer to also farm How to convince an abalone farmer to also farm seaweeds seaweeds

How to convince an abalone farmer to also farm How to convince an abalone farmer to also farm seaweeds seaweeds

Deborah V. Robertson-Andersson1, Ana M. Nobre2, Amir Neori3, Kishan Sanker6, Gavin Maneveldt1,

Max Troell4,5, Christina Halling5 and John J. Bolton6

1 The Department of Biodiversity and Conservation Biology Department, University of the Western Cape, Bellville, South Africa.

2 IMAR, Faculty of Sciences and Technology/UNL. Caparica, Portugal. 3 Israel Oceanographic and Limnological Research, National Centre for

Mariculture, Israel.4 Beijer Institute, Stockholm, Sweden.

5 Department of Systems Ecology, Stockholm University, Stockholm, Sweden.

6 Botany Department, University of Cape Town, South Africa.

Deborah V. Robertson-Andersson1, Ana M. Nobre2, Amir Neori3, Kishan Sanker6, Gavin Maneveldt1,

Max Troell4,5, Christina Halling5 and John J. Bolton6

1 The Department of Biodiversity and Conservation Biology Department, University of the Western Cape, Bellville, South Africa.

2 IMAR, Faculty of Sciences and Technology/UNL. Caparica, Portugal. 3 Israel Oceanographic and Limnological Research, National Centre for

Mariculture, Israel.4 Beijer Institute, Stockholm, Sweden.

5 Department of Systems Ecology, Stockholm University, Stockholm, Sweden.

6 Botany Department, University of Cape Town, South Africa.

How do you tell an economist the value

of science?

How do you tell an economist the value

of science?

How do you tell an economist the value of science?

most scientists - seem to take it for granted that scientific knowledge is valuable for its own sake

value of science must depend exclusively upon the value of its effects or consequences which somehow affect the welfare or happiness of sentient beings

draw up a debit and credit account" for science

Lars Bergström Notes on the Value of Science

How do you tell an economist the value of science?

most scientists - seem to take it for granted that scientific knowledge is valuable for its own sake

value of science must depend exclusively upon the value of its effects or consequences which somehow affect the welfare or happiness of sentient beings

draw up a debit and credit account" for science

Lars Bergström Notes on the Value of Science

OverviewOverviewOverviewOverview

How does a phycologist draw up a

credit and debit account?

OverviewOverviewOverviewOverview

How does a phycologist draw up a

credit and debit account?

Ecological-economic assessment by Differential Drivers-

Pressure-State-Impact-Response (DPSIR) approach

Places an economic value on IMTA by looking at the

costs/benefits of implementation of the

system compared to a system without

IMTA

The current drivers for integrated seaweed aquaculture

in South Africa.

Socio-economic, environmental and multiplier effects.

Differential DPSIRDifferential DPSIRDifferential DPSIRDifferential DPSIR

(i) Drivers - the anthropogenic activities at a given moment in

time that may have an environmental effect and

is a socio-economic component of the DPSIR.

(ii) Pressure - positive or negative direct effects of the Drivers

(iii) State - the condition of the ecosystem at a given moment

in time resulting from both anthropogenic

Pressures and natural factors.

(iv) Impact - the environmental effect of the Pressures, i.e. the

changes on the State of the ecosystem during a

given time period or between two scenarios. An

environmental Impact can be either positive or

negative.

(v) Response - management actions and policies that change

the Drivers.

6

8

10

12

14

16

18

20

22

24

26

28

30

Aug-02

Sep-0

2

Oct

-02

Nov-02

Dec-0

2

Jan-

03

Feb-0

3

Mar

-03

Apr-03

May

-03

Mea

n w

et w

eig

ht

(g)

Mixed diet

Rotation

Fresh Kelp

Fresh Kelp + formulated feed

Formulated feed

Drivers

Lack of and decrease in kelp resource to feed increasing

industry.

High seawater temperatures cause artificial feed to ferment

and bloat abalone.

Mixed diets are known to give better growth

rates.

Potential over-harvesting and decrease in

epiphyte densities on kelp after harvesting.

Limited suitable coastal areas for open ocean

cultivation.

Recirculation – protection from ‘HAB’s’ = 33 %

loss in profits for 1 year.

Rational for IMTARational for IMTARational for IMTARational for IMTA

Effect of diets on abalone growth rates

Naidoo et al. 2006Naidoo et al. 2006

Effect of harvesting on regrowth of obligate epiphytes on kelp

0

0.5

1

1.5

2

2.5

3

3.5

Control harvest

g e

pip

hy

tes

/kg

of

ke

lp

Anderson et al. 2006Anderson et al. 2006

Drivers

Lack of and decrease in kelp resource to feed increasing

industry.

High seawater temperatures cause artificial feed to ferment

and bloat abalone.

Mixed diets are known to give better growth

rates.

Potential over-harvesting and decrease in

epiphyte densities on kelp after harvesting.

Limited suitable coastal areas for open ocean

cultivation.

Recirculation – protection from ‘HAB’s’ = 33 %

loss in profits for 1 year.

Rational for IMTARational for IMTARational for IMTARational for IMTA

Red tide moving towards abalone intake

Drivers

Lack of and decrease in kelp resource to feed increasing

industry.

High seawater temperatures cause artificial feed to ferment

and bloat abalone.

Mixed diets are known to give better growth

rates.

Potential over-harvesting and decrease in

epiphyte densities on kelp after harvesting.

Limited suitable coastal areas for open ocean

cultivation.

Recirculation – protection from ‘HAB’s’ = 33 %

loss in profits for 1 year.

Rational for IMTARational for IMTARational for IMTARational for IMTA

Commercial integrated seaweed abalone system:Commercial integrated seaweed abalone system: 50 % recirculation50 % recirculationCommercial integrated seaweed abalone system:Commercial integrated seaweed abalone system: 50 % recirculation50 % recirculation

Intake Intake

Seaweed paddle ponds Seaweed paddle ponds

Sump Sump

Drum filter Drum filter

Abalone

tanks

Abalone

tanks

Header tank Header tank

Pump Pump

Seaweed harvest

point

Seaweed harvest

point Outlet Outlet

Feed savings – 120 tons of seaweed produced

Faster abalone growth rates – 6 months less spent on farm

Energy reduction – 350 MWh yr-1

Reduction in concentration and total mass of discharged

nutrients

R104 per kg N removed

R48 per kg P removed

Kelp beds not being harvested

R146 per m3

Change in GHG emission

R 200 per ton CO2

Benefits of an IMTA SYSTEM:Benefits of an IMTA SYSTEM:Benefits of an IMTA SYSTEM:Benefits of an IMTA SYSTEM:

Cost to build to 1 pond in IMTA system

R 51 000

Total cost for 4 ponds

R 0.3 million (once off cost)

Labor for seaweed ponds

R140 000.yr-1

Costs of an IMTA SYSTEM:Costs of an IMTA SYSTEM:Costs of an IMTA SYSTEM:Costs of an IMTA SYSTEM:

Feed savings – R 235 000 yr-1

Faster abalone growth rates – R 720 000 yr-1

Energy reduction - R 56 000 yr-1

Discharged nutrients

44 % decrease in N production

23 % decrease P production

Kelp beds

2.2 ha.yr-1 not being harvested

Change in GHG emission

345 tons.yr-1 ton CO2

Impacts of an IMTA SYSTEM:Impacts of an IMTA SYSTEM:Impacts of an IMTA SYSTEM:Impacts of an IMTA SYSTEM:

ImpactsImpacts ImpactsImpacts

ENVIRONMENTAL SAVINGS (82 % of the net profit)

The seaweeds take up 12 tons of CO2 y-1

An additional 333 tons of CO2 y-1 are saved by

reducing the electricity usage

92.6 % of N is removed

A 3 % reduction in the harvesting of natural kelp beds

6 % decrease in green house gas emissions by the

farm

17.8 % increase in P emissions

NET PROFIT = R 62. 791

million.yr-1

NET PROFIT = R 62. 791

million.yr-1

SEAWEED PADDLE POND SYSTEM:SEAWEED PADDLE POND SYSTEM: Costs and savings Costs and savings

SEAWEED PADDLE POND SYSTEM:SEAWEED PADDLE POND SYSTEM: Costs and savings Costs and savings

ENVIRONMENTAL SAVINGS:

49 800 Euro yr-1 of avoided costs for N removal;

1 400 Euro yr-1 estimated as the environmental costs for the

increase in the P loads;

300 Euro yr-1 of avoided costs concerning kelp bed

restoration;

4 500 Euro yr-1 of avoided costs of GHG emission offset.

The economic value = 494 200 Euro yr-1

direct benefits to the aquaculture business (estimated as

the change in the aquaculture net profit, 53 200 Euro yr-1

(ZAR 871 000 )) and

indirect environmental benefits (estimated as the value

of the externalities, 541 000 Euro yr-1 (ZAR 3839 000))

ZAR 9.495 = € 1*

*FMI 2007 and includes purchasing power

parity

ZAR 9.495 = € 1*

*FMI 2007 and includes purchasing power

parity

Conclusion:Conclusion:

Nick Loubser I & J General manager

“The actual financial benefits are difficult to determine but in ball park terms we

calculate that the seaweed contributes at least R500 000 a year to the farm in feed cost savings alone.”

Our calculations show a savings of R871 000 per year.

McVeigh, S. J.. 2007. First Green Filters for aqauculture. Fishing industry news. June 2007. pg 16 - 17.

Nick Loubser I & J General manager

“The actual financial benefits are difficult to determine but in ball park terms we

calculate that the seaweed contributes at least R500 000 a year to the farm in feed cost savings alone.”

Our calculations show a savings of R871 000 per year.

McVeigh, S. J.. 2007. First Green Filters for aqauculture. Fishing industry news. June 2007. pg 16 - 17.

THANK YOUTHANK YOU

ACKNOWLEDGEMENTS

I would like to extend special thanks to the following organizations without whose help

this project would have

been impossible:Swedish and South African Collaborative Program

I & J Mariculture farm

N R F

SANCOR Prestige Student travel grant