Recirculating Aquaculture Systems - Comparison To Net Pen

Information about recirculating aquaculture systems and net pen systems has been excerpted from a Conservation Fund / SINTEF presentation whose authors include: Trod W. Rosten, Kristian Henriksen, Erik Skontorp Hognes, Brian Vinci and Steve Summerfelt.   We include a direct link to the complete presentation below.

Model Land-based Recirculating Aquaculture Systems farm (32 million US $ )

Invested equipment:

  • 40,000 m3 of rearing tank volume
  • 25,500 m2 of building area
  • 2,500 m2 processing facility
  • 885 m3/min of pumped RAS flow
  • Pumps and Piping
  • Screen filters
  • Biofilters
  • Gas Conditioning Filters
  • 1.08 – 1.26 kg feed per m3 supply water
  • Feeding Systems
  • Backup Generators

Model Net Pen farm (12,3 million US $):

  • Two production sites, each with six net pen cages.≈587,000 m3 net-volume
  • 120,000 m2 area  footprint visible at sea
  • ≈179,000 m2 area footprint incl. no thoroughfare zone
  • ≈463,000 m2 area footprint incl. no fishing zone

Invested equipment:

  • 3 licences
  • 12 Floating rings (157m Ø)
  • 24 nets (25 m deep)
  • 2 mooring systems
  • 2 boats
  • 2 feed barges (150 Mtons)
  • 12 camera systems
  • 12 feed distributors
  • 12 power systems

Model Land-based Recirculating Aquaculture Systems Farm

  • One production site for all life-stages
  • Four cohorts per year
  • Growth based on thermal growth coefficients from Freshwater
  • Institute growout trials, adjusted down by 10%:
  • 1.1 for Fry
  • 1.25 for Smolt
  • 1.8 for Pre-growout
  • 2.2 for Growout
  • Mortality per generation 16%


Feed conversion ratios:

  • 0.75 for Fry
  • 0.90 for Smolt
  • 1.0 for Pre-Growout
  • 1.1 for Growout
  • Overall Feed to Whole Fish Produced (kg/kg): 1.09


Rearing Density

  • 80 kg/m3 maximum

Harvesting:

  • Time from first feeding to first harvest: 21 months
  • Harvest every week of the year
  • Each cohort harvested over 13 weeks
  • One grisle harvest at ~1.2 kg for 50% of males
  • Harvest in total: 3947 M.tons LWE, 3300 M.tons HOG (5% purge loss / 12% HOG loss)
  • Initial harvest weight (whole fish): 4.5 kg
  • Average harvest weight (whole fish): 5.1 kg
  • No downtime in the bio-plan

Model Net Pen farm:

  • 2 production sites & 3  licences of 780 M.tons of maximum total biomass at sea.
  • Two transfers of smolts to sea annually, to one site
  • S1 at 1st of April, 100 grams, 520' smolts in three cages
  • S0 1st of August, 75 grams, 520' smolts in three cages
  • Growth based on the Skretting table, Specific Growth Rate
  • (SGR), adjusted down by 12 %.
  • Mortality per generation approximately 16,1 % (average in
  • Mid-Norway in 2011) (Norwegian Food Safety Authority 2011).
  • Economic feed conversion ratio: 1,27 (average in Norway over the last ten years) (Directorate of Fisheries 2013).

Rearing Density

  • 25 kg/m3 maximum

Harvesting:

  • Time from first feeding to first harvest: 24 - 31 months
  • Time at sea before first harvest: 16 months
  • Harvest 8 months of the year
  • Harvest S1 from July to October
  • Harvest S0 from November to February
  • Harvest in total: 3 975 M.tons LWE, 3 299 M.tons HOG
  • (5 % purge loss /12 % HOG loss)
  • Average harvest weight (whole fish) : 4,5 kg
  • Two months of fallowing between production cycles

Recirculating Aquaculture Systems Profitability

Complete Presentation (Workshop #6)

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