Copper alloy Mariculturein

Southern Africa Step 2

Prof Tom HechtAdvance Africa Management Services cc

Copper Alloy mesh in marine finfish cage culture

A scoping study in southern Africa (STEP 1)

Prof Tom HechtADVANCE AFRICA Management Services cc

Dealing with farmer perceptionsBIO-FOULING

After 8 months exposure, some seaweed caught in links but no settlement

Spring and summer fouling in Algoa Bay (2 months exposure)

Farmer perceptions and questionsSeveral farmers are gearing up to deploy marine cages (Saldanha and Pemba)

Alloy cages are expensive in relation to nylon or polyethylene net pens -- No detailed information on Life Cycle Costs

Unsure and sceptical about industry claims about use of alloys in marine cage culture- particularly - no bio-fouling, copper residues in fish

Questions: 1.How would alloys perform under local sea conditions in comparison to traditional materials? 2. Are fish tainted by release of Cupric ions?3. What are comparative operational costs?

What does CDA and ICA have to do?• Undertake detailed life cycle cost analysis (Capital, operational, resale).• Demonstrate anti-fouling properties of alloys (Step 2)• Determine effect of Cu leaching on fish quality (leaching currently being

investigated by University of New Hampshire in association with US Navy)• Undertake comparative growth trials in alloy and polyethylene net pens

(Step 3)

Experimental cages to be deployed in Turkey July 2011

High pressure cleaning of nets

Anti-biofouling demonstration• CDA and ICA has contracted Advance Africa to undertake a biofouling demonstration

experiment (So now you know where part of your contributions went)

• Project title - Comparative bio-fouling of selected fish cage mesh materials in the cold-temperate Benguela System and in the tropical Western Indian Ocean.

• Aim: To demonstrate the anti-fouling efficacy of copper alloy mesh in three high potential aquaculture locations in the Atlantic and the Western Indian Ocean.

• Chile - 650 tonnes of copper alloy installed at end of 2010, with a total order backlog > 2000 tonnes (Source: Langley Gace, ICA).

• Materials – UR30TM chain link mesh, Seawire, Nylon, Polyethylene

• 3 Sites: (Different environments, different settlement rates, different species composition, strategic decision).

1. Saldanha Bay – (Best site for Salmon farming in RSA but applicants hesitant to begin because of the fouling problem)

2. Pemba Bay (Mozambique) (Warm subTropical) (Cobia and Kob)3. St Anne Island (Seychelles) (Tropical) (Master Plan)

Experiment 1.• Duration: 5 months x 2 (winter / summer and SE Monsoon / Inter-

monsoon) – assess seasonal differences• 5 frames per site with 12 (30x30cm) panels (3 replicates per material)• Remove 1 frame / month• Photograph frame and allocate fouling index to each panel • Identify fouling organisms to lowest taxon and weigh each• Repeat every following month• Analyse fouling rate, species succession and species composition per

material per season by weight and by visual index (ANOVA and Tukeys least significant test)

• Prepare manuscript for publication in peer reviewed journal

Experimental design

Frames and panels

Seawire ( Luvata)

Nylon and polyethylene to boring for Copper People – so not included

Experiment 2.

•1 Frame per site •3 panel replicates (400x500mm) per material•Duration 10 months•Monthly visual index per panel (1 zero fouling, 5 extreme fouling)•At end of experimental period – Remove frame •Identify all organisms to lowest taxon, count and weigh•Analyse photographic index data and empirical data using ANOVA•Compare species composition and net fouling rate over time.•Publish in peer reviewed journal

Some Expected Results

• It is expected that the results will prove the antifouling properties of the alloy materials in comparison to normal cage netting materials.

• The data will show whether there are any seasonal differences in the rate of bio-fouling and also differences in seasonal composition of bio-fouling organisms.

• The data will be used to extrapolate the frequency (and the cost) at which nylon and polyethylene nets would have to be cleaned in comparison to alloy mesh nets. This will demonstrate some of the operational saving associated with alloy mesh nets.

STEP 3 (2013)

• Comparative growth trials with partners• Alloy mesh pens provided by ICA and CDA • Farmer partner pays for all other Capex and

Opex• Direct cost comparisons