Copper Alloy mesh in marine finfish cage culture

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Copper Alloy mesh in marine finfish cage culture

• A scoping study in southern Africa
• Tom Hecht
• ADVANCE AFRICA Management Services cc

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Advantages of copper alloys

• High resistance to macro-fouling in sea water
  resulting in
• Improved water flow through cages,
• Improved DO levels, reduced parasite load,
  reduced infections, lower FCR,
• Higher production as a consequence of faster
  growth and lower mortality (no net changes no
  stress from predators)
• The material is strong and predators cannot cause
  damage thereby reducing fish losses due to
  predation and rate of escape of fish from cages.
• Lower maintenance no net changes no net
  cleaning
• Lower costs avoid need for predator net avoid
  antibiotics
• Reduced environmental impact can be made from
  recycled materials can be recycled after use no
  nets to dispose of.
• Potential for consumer market positioning as more
  environmentally appropriate fish production

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AVAILABLE COPPER ALLOYS FOR MARINE CAGES
Flattened expanded copper nickel 90Cu/10Ni.
Used for square rigid cages gt30 yrs. Wide range
of mesh size and gauges.
Chain link woven UR30TM brass 64 Cu, 35 zinc,
0.6 Sn, 0.3 Ni plus micro-alloying elements.
Appropriate for many types of flexible enclosures
including circular and square cages. This
material has been in use for gt10 yrs.
Welded silicon bronze (SeawireTM) Comprising 97
Cu, 3 Si plus manganese and micro-alloying
elements. Suitable for attachment to rigid
structures and for square cages.
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UR30TM COPPER ALLOY (64Cu, 35Zn,0.6Sn, 0.3Ni
and other micro-alloying elements
Most commonly used alloy
Yellowtail in UR30 cage. Note limited
bio-fouling.
UR30 net being prepared for square salmon cage at
Van Diemen Salmon farm, Tasmanaia
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Scoping study objectives

• Provide brief overviews of the current state of
  marine aquaculture in RSA, Namibia and
  Mozambique.
• Outline current government policies and recent
  actions with respect to marine aquaculture
  developments.
• Assess the potential size of the cage culture
  industry in the region.
• Inform / sensitize commercial operators and
  fisheries / aquaculture authorities about the
  merits of alloy cages and assess the potential
  interest in alloy cages.
• Identify possible local barriers to alloy cage
  deployment through interviews with local
  environmental NGOs
• Identify any possible institutional barriers and
  or regulatory barriers to deployment of alloy
  cages.
• Identify possible partners and location/s for
  pilot commercial trials
• Assess acceptability of investment costs and or
  lease costs
• Develop an experimental design in collaboration
  with farmer/s to test the efficacy of alloy cages
  cf. to nylon net pens.
• Develop a basic costing for a commercial pilot
  project if desirable.
• Develop the logistics for the implementation of a
  commercial pilot project if desirable.

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Country overviews Namibia
Mariculture sites Walvis Bay, Luderitz and
Swakopmund 14 producers, mainly oysters, 2
mussel farms an d 1 shore based abalone farm.
Oyster production 560 900 tonnes pa. Exported
to SE Asia, Europe and RSA. Excellent regulatory
framework (Aquaculture Act) and streamlined
permitting procedures and strongly supported by
Government.

• Luderitz at core of central Benguela upwelling
  cell.
• Sulphur eruptions prevalent from 50km N of
  Luderitz toxic to marine organisms.
• Luderitz prone to low dissolved oxygen levels
  .
• Cage culture opportunity Low to nil (too risky)

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Farm locations South Africa
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Country overviews South Africa
Abalone 980 t pa 12 farms
Seaweed for abalone feed
Land based pump ashore
Mussels, 600-800 t pa, Spanish raft, Saldanha
Bay, 2 farms
Artificial feeds
Oysters 450 t pa, mainly PE, Saldanha, Knysna.
Consumed locally and some exported EU.
Kob broodtsock Pemba
(Mozambique) Richards Bay
Planned farms Mosselbay - Yellowtail Saldanha,
- 2 x Salmon Experimental - Algoa Bay
(Yellowtail) Richards Bay (Kob)
Yellowtail cages, Algoa Bay 2009 -
2011
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Country overview Mozambique
Current activities Prawns (600 t) and seaweed
(1200 t dry) Excellent regulatory framework,
excellent incentives for FDI Cage culture
started at Pemba, Cabo Delgado (AquaPemba)
Species Cobia and Dusky Kob Investor HIK
Abalone, Hermanus. Pre-commercial phase 2009-2011
_at_ US3 million Commercial phase 2012gt to 2000 t
pa _at_US 7 million
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Rating Site location Country Cage type Additional information needed
A Pemba Mozambique Surface None
A Nacala Mozambique Surface Depth profiles, Bottom type, Current speeds Water quality
A Saldanha Bay South Africa Surface None
A Mosselbay South Africa Surface Water quality data
A Algoa Bay South Africa Surface/Submerged Significant wave height andwater quality data
B- Gansbaai South Africa Surface/Submerged Depth profiles, Bottom type, Current speeds Significant wave height
Plus Seychelles, Madagascar, Reunion, Mayotte,
Mauritius
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(No Transcript)
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The problems
Net fouling, Algoa Bay
Predators (Barracuda) inside net pen
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The potential for cage culture
Note This excludes the potential of the
entire WIO region
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Dissemination of information and farmer response
Information pack compiled and sent to all public
and private sector stakeholders in three countries
Farmer response -- cautious optimism to quiet
enthusiasm. Not surprising. (Who jumps in
first?)
Regulatory authorities -- were enthusiastic as
they recognised the application to realize
development goals.

• Farmer opinions and questions
• Except for Irvin and Johnson, farmers unaware of
  copper alloy mesh and cages.
• University of Stellenbosch aware of copper alloy
  cages, previous contact with CDA (Africa).
• Once aware of benefits high degree of interest
  by farmers with finfish farming interests.
• Oyster farmers (as expected) expressed a more
  cautious approach.
• Most frequent questions product lifespan, cost,
  env. impact, additional floatation.

Primary motivators Intense biofouling and
predators
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Regulatory approval
Dear Prof. Hecht,This e-mail serves to inform
you that the Marine Aquaculture
Directorate(DAFF) has reviewed the information
supplied by you to Mr Semoli, on theuse of
Copper Alloy mesh technology in marine
aquaculture.The Directorate has no objections
to the use of copper alloy meshtechnology for
use in marine aquaculture systems.RegardsMiche
lle Pretorius (Cand. Sci. Nat.)Department of
Agriculture, Forestry FisheriesPrincipal
Enviornmental Officer Marine Aquaculture
EnvironmentalAssessmentTel 27 (21) 402
7034Fax  [phone]Cell 082 647
2263E-Mail MichellePR_at_nda.agric.za
ltmailtoPhumelele.mhlongo_at_gpw.gov.zagt Private
Bag X2 Roggebaai, 8012, Cape Town
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Conclusions and recommendations

• Cage culture in RSA and Mozambique is nascent but
  interest is growing.
• Emerging nature provides opportunity to expose
  farmers to benefits of copper alloy cages from
  the start.
• It makes logical sense for the CDA (Africa) to
  undertake joint commercial trials with industry
  to prove the local business case.
• Deployment of copper alloy panels and monitoring
  at selected sites would be valuable marketing
  tool.
• Given feedback, pivotal for CDA (Africa) to
  develop a marketing brochure that provides
  indicative costs, a cost / benefit analysis,
  information on buyback for recycling inclusive of
  prices relative to new costs, possibility of
  leasing and costs involved, available mesh size,
  weight, additional floatation required, assembly
  modes, etc. FishAfrica - Tradeshow CT,
• CDA (Africa) should further explore opportunities
  in the Western Indian Ocean region and in
  particular by Reunion (which is the most advanced
  country with respect to marine fish farming in
  the region), Seychelles, Madagascar and
  Mauritius.
• There may be an opportunity for the CDA (Africa)
  to develop a new product for the oyster farming
  industries in Namibia and South Africa (but see
  below).

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THE REST
A. Selection of partners for commercial trials
1. The AquaPemba Cobia project in Pemba,
Mozambique (HIK Abalone) 2. The University of
Stellenbosch / Dept. Of Science Technology
Dusky Kob project in Richards Bay OR Yellowtail
project in Algoa Bay
B. Experimental systems and design
1. Comparative growth and production trials
2. Anti-fouling demonstration project
C. Implementation and project management
D. Pro forma Budgets
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Comparison of Commercial partners

• AquaPemba
• Commercial project
• Bioregion Tropical
• Cobia and kob
• Commercial phase 2000 tonnes pa
• Findings not widely disseminated but success
  will result in further investment in WIO.
• Total budget to commercial US1o M

• Stellenbosch /DST
• Development project
• Bioregion Temp/Trop
• Kob or Yellowtail
• No direct commercial phase
• Findings widely disseminated but does not
  necessarily lead to investment in RSA and or
  WIO
• Total budget to completion R6 M

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Commercial trials

• Comparative growth and production trial.
• Basic hypothesis Because there is no biofouling
  the environmental conditions (through flow rate,
  O2) within the alloy cages should be better than
  in nylon cages, which will manifest in higher
  growth rates, lower FCR, lower stress level and
  healthier fish with lower mortality levels.

• Anti fouling demonstration trial
• Demonstrate economic benefits of copper alloy
  meshes in four bioregions (Cold west coast to
  Tropical)

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Implementation and project management project
management company to implement and project
manage Pro Forma Budgets Being drawn up at
present.
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IDEA FOR CDA (Africa)