OPEN OCEAN AQUACULTURE:

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OPEN OCEAN AQUACULTURE TECHNOLOGICAL AND
ENVIRONMENTAL ISSUES
Daniel D. Benetti Associate Professor Director,
Aquaculture Program Division of Marine Affairs
and Policy
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A new way to feed the world Aquaculture is a
good thing, in spite of environmentalists
concerns
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CRITERIA FOR CANDIDATE SPECIES FOR OPEN OCEAN
AQUACULTURE
1) Native species/endemic to the region (SE US,
Gulf and the Caribbean) 2) Market demand and
value 3) Technology availability 4) Aquaculture
performance rates of growth, survival and feed
conversion
Mutton Snapper, Lutjanus analis
Cobia, Rachycentron canadum
Cobia, Rachycentron canadum
Greater amberjack, Seriola spp
Tuna, Thunnus spp
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HATCHERY FOR RD AND PRODUCTION OF HIGH-VALUE
MARINE FISH IN THE FLORIDA KEYS
Rotifer/Artemia
Microalgae/Phytoplankton
Larval rearing/Intensive
Maturation/Broodstock
Mesocosm/Semi-intensive
Growout/Cages
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Comparative Growth During Early Developmental
Stages 45 DPH (Days Post Hatch) 6 weeks
Cobia 5.5 g 11.5 cm (4.5 in) Snapper 0.2
g 2.0 cm (1.0 in)
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Cobia are shipped and stocked at 35-40 DPH _at_
3.0-5.0 g and 7-10 cm
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Harvesting, Transporting and Shipping Fingerlings
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Add new slides with pictures from shipment to
Eleuthera Trucks, convoy, Boeing, etc.
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Receiving and Transporting Fingerlings in Puerto
Rico
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ISLA CULEBRA, PUERTO RICO
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Stocking the Offshore Cages off Culebra Island,
Puerto Rico
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OFFSHORE SYSTEMS
SeaStation 3000 - Ocean Spar
Culebra Island, Puerto Rico
South Eleuthera, Bahamas
AquaSense, LLC
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Cobia fingerlings are stocked in submerged
nursery cages inside SeaStations 3,000 m3 off
Culebra Island, Puerto Rico, and South
Eleuthera, the Bahamas
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STOCKING DENSITIES
20,000 fingerlings stocked/3,000 m3 cage (2,700
m3) 7 fingerlings/ m3
20,000 fingerlings _at_ 90 survival 18,000
harvest/market size fish (6 kg) 18,000 fish _at_ 6
kg/ea 108.000 kg (108 Ton) / 2,700 m3 40 kg/
m3
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GROWOUT
Pellets AquaExcel 5310 (Burris) Extruded, slow
sinking, 53 CP, 10 CF
FCR 1.95 on pellets made of 50 fish meal
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ENERGY CONVERSION NATURE VS. OFFSHORE AQUACULTURE
NATURE - WILD
OFFSHORE AQUACULTURE
90 LOSS BETWEEN TROPHIC LEVELS OF THE FOOD CHAIN
1000 KG PHYTOPLANKTON
1000 KG PHYTOPLANKTON
100 KG ZOOPLANKTON
100 KG ZOOPLANKTON
10 KG ANCHOVIES
10 KG ANCHOVIES

20 DRY
1 KG SALMON
Fish Meal
Fish Human Cons.
2.2 times more efficient in producing COBIA/ MOI/
SALMON!
FISH ARE 20 DRY (80 MOISTURE) THEREFORE THE FCR
IN NATURE IS 101 (WETWET) or 21 (DRYDRY)
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Transform all data into dry matter Fish Meal
100 anchovy, mackerel, sardine, pilchard,
menhaden, etc. 80 is moisture 20 dry matter
45 fish meal Pellets
(Aquaculture Feeds) 90 dry 45 cheap
grain fillings (soybean meal, etc.) 1 kg pellet
0.45 kg fish meal Experimental data Feed
Conversion Rate (FCR) 2.0 1 2.0 kg
pellet 1 kg cobia (wet weight) (90 dry,
10 moisture) (80
moisture, 20 dry) 1.8 kg dry pellet 0.2 kg
dry cobia (50 fish meal) 0.9 kg dry fish
meal 0.2 kg dry cobia 0.9 / 0.2 4.5
Pellet efficiency 4.5 1 Nature
Efficiency 10 1 (wet or dry weight) Pellet
Efficiency 4.5 1 (10 / 4.5
2.22) Mariculture is 2.2 times more efficient
than nature in transforming small fish such as
anchovies into edible, high-value fish such as
cobia, moi and salmon for human consumption

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Transformation Efficiency

• In nature, it takes 10 kg of small fish
  (anchovies, etc) to produce 1 kg of cobia
• or other carnivorous fish for human consumption.
  Hence, the efficiency is 10 1.
• It takes 0.9 kg of fish meal (dry) to produce 0.2
  kg of dry cobia.
• Hence, the efficiency is 0.9 / 0.2 4.5 1.
• It takes 1.8 kg of whole dry pellet to produce
  0.2 kg of dry cobia.
• Therefore, the efficiency is 1.8 / 0.2 9.
• The actual whole pellet efficiency is 9 1.
• 5) This is the whole pellet (fish meal, grains,
  etc.) efficiency, not just the fish meals.
• It's like the whole pellet is contaminated with
  material that's not fish meal
• (in this case, mostly cheap grain fillings).
• _at_ 50 fish meal AND FCR 2, the fish meal
  efficiency in the pellet is 4.5 1
• (i.e., 2.2 times more efficient than nature).

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• Transformation Efficiency in Percentages ()
• 1) Nature (1/10) 100 10
• (10 of biomass ingested as menhaden transformed
  in new cobia biomass)
• Dry Fish Meal (0.2 / 0.9) 100 22
• Pellet Efficiency (fish meal fillings)
• (0.2 / 1.8 100 11

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Environmental assessment

• Chemical factors
• Total suspended solids
• Ammonia
• Nitrite
• Nitrate
• Phosphate
• Dissolved oxygen
• Organic matter
• Nitrogen

• Physical factors
• Bathymetry (depth profile)
• Bottom type (preferred sandy)
• Coastal topography
• Wind velocity/direction/fetch
• Currents and tides
• Wave height (max/min/average)
• Air and water temperature
• Turbidity

• Socio-economic studies
• Acceptance of project
• Local communities
• Partnership Fishermen Association
• Educational component
• Elementary / High School / Technical Level
  Curricula
• Teachers Materials / Talks, etc.

• Biological factors
• Fouling
• Chlorophyll
• Productivity
• HABs
• Assemblage
• Benthic studies

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Sampling Protocol
Preliminary Results
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New Hampshire Offshore Environmental Observations

• Maximum Feed/Day. 780 pounds. Time Two years.
• Water depth 130 feet. Cage height 50 feet.
  Current 20-30 Cm/sec.
• Inorganic N No difference upstream or
  downstream.
• Total organics in sediment has stayed at 3 by
  weight
• Benthic fauna no statistically significant
  changes in species ratios
• Fish Schools of small pollock and large striped
  bass.
• Invertebrates starfish, crabs, tunicates,
  bryozoa, hydroids
• Mussel culture very successful in terms of
  growth/quality

J. McVey, NOAA Sea Grant, March 2004
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Puerto Rico Offshore Environmental Observations

• Maximum Feed/Day. 600 pounds. Time 18 mos.
• Water Depth 95 feet. Current 20-30 Cm/sec Max.
• Inorganic N upstream or downstream.
• Total organic N No difference in sediment, has
  stayed the same as control at about 4.5.
• Benthic Fauna Abundance of macroinvertebrates at
  control site only marginally different (Plt0.05)
  with station at bottom center of cage. Species
  diversity and evenness remained unchanged at all
  other sampling sites.
• Fish 37 species vs four species before project.
  Schools of jacks, Decapturus and Caranx, cobia,
  barracuda.
• Invertebrates Spiny lobsters, crabs, urchins,
  conch, pearl oysters.

J. McVey, NOAA Sea Grant, March 2004
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Hawaii Offshore Environmental Observations

• Maximum Feed/Day. 4000 pounds. Time 3 years.
• Water Depth 130 feet. Current 10-20 Cm/sec.
• Inorganic N No systematic changes for nitrite or
  nitrate at any station but some measurable change
  at cage rim for ammonia after feeding, reduced to
  5 micrograms/liter, at 100 meters but no change
  at 400 meters.
• Total Organic N of organic N in sediments
  ?????
• Benthic fauna Change to 4-5 times higher biomass
  of detritivores under cage, 80 m less, 400 m with
  no change.
• Fish 24 species, large schools of jacks
  (Decapturus and Caranx), Seriola, sand bar
  sharks, filefish.
• Invertebrates Tunicates, sponges, bivalve
  molluscs??????

J. McVey, NOAA Sea Grant, March 2004
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Observations Relative to Specific
Criteria (Based on Hawaii Administrative Rules,
Title 11, Department of Health, Chapter 24,Water
Quality Standards)
Geometric mean not to exceed the given value
Not to exceed more than 10 of the time
Observations Maximum value observed and Number
of Occurrences ( )
Total of observations 373 Parameter Total
Nitrogen mg N/L Ammonia Nitrogen mg
NH4/L Nitrate Nitrite N mg (NO3NO2)/L Total
Phosphorus mg P/L
150 250 gt150 to 250 (2)
3.5 8.5 gt 8.5 to 69 (9) gt3.5 lt 8.5
(32) 5.0 14.0 always lt 5 20.0 40.0
gt20 lt31 (1) gt 40 (0)
pH 8.2/-0.05 Temperature 0.5oC from
ambient Salinity 35/-0.5 D.O. gt80
Helsley et al. 2003
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Conclusions from water sampling

• No samples had values in excess of allowable
  values under the NPDES permit
• NH4 is the only nutrient that is ever above
  background
• NH4 is only above background very near the cage
  for a few hours about two hours after feeding

Helsley et al. 2003
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Summary of Environmental Observations

• Inorganic nitrogen concentrations are not changed
  significantly except at the net.
• Organic nitrogen in sediments no change at levels
  below 1000 pounds of food per day
• Benthic communities will shift to more
  detritivores at higher levels of organic N.
• Fish and large invertebrate species diversity and
  biomass will increase near and on offshore cages.
• Oxygen levels and benthic appearance have not
  changed and support biota under cages.

J. McVey, NOAA Sea Grant, March 2004
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Recorded and fitted growth rates of cobia
(Rachycentron canadum) in the offshore cages of
Snapperfarm off Culebra, Puerto Rico, from
hatching to one year of age
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gt 95 mature
Onset of maturation
Recorded and fitted Van Bertalanaffy growth of
cobia (Rachycentron canadum) in the offshore
cages of Snapperfarm off Culebra, Puerto
Rico from hatching past one year of age (14
months)
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Comparative Growth of Cobia in Offshore Cages in
Puerto Rico and The Bahamas
Squares - Snapperfarm, Puerto Rico _at_ 27-31
oC Circles - AquaSense, South Eleuthera _at_ 22-25 oC
Preliminary Data Q10
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RESULTS
12 months (1 year) from eggs Total Feed
31,435.12 kg Total Morts 342 Harvested
114 Estimated Remaining in cage 2,500 Average
weight 6.03 kg (SD2.4 CV39) or 13.3 lb
1.7-9.1 kg FCR 1.95 Survival gt 90 18 months
(1.5 yr) from eggs Total Feed 52,255.20
kg Total Morts 663 Harvested 2,175 Estimated
remaining 100s Average weight 7.75 kg (17.06
lb) 5-16kg FCR 2.29 Survival 75 Total
biomass harvested 15 Ton (lt 33,000 lb) Total
number of fish 3,200
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12-month-old, 9 kg (20 lb) cobia cultured offshore
Length x Weight Relationship Exponent Wild
3.08 Cultured 3.43
12-month-old average was 6 kg (12.4 lb) (some
over 20 lb) 18-month-old average is 7.7 kg (17
lb) (some over 30 lb)
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BIOFAULING! Pros and Cons
Panulirus argus
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HARVESTING AND SHIPPING - HIGH-END MARKET
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MARKET
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CONCLUSIONS

• Maturation / Prophylaxis / Quarantine
• Spawning (conditioned/hormone induced)
• Larval husbandry technology
• Nursery techniques (hatchery/offshore)
• Transportation (shipping/stocking)
• Growout technology (offshore)
• Market and commercialization
• Species Cobia exhibits extraordinary potential
  for
• open ocean aquaculture
  throughout its
• distribution range
• Addressing industry needs and issues/concerns
  from
• agencies, NGOs, press and public at large
• native species no GMOs probiotics only
• FDA approved chemicals (except food additive
• eugenol) adv. growout technology exposed sites
  
• offshore high efficiency feeds, low FCR, reduce

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Addressing Industry Needs as well as Concerns of
Agencies, NGOs, Environmentalists, Media, and
the Public at Large

• Species
• Native Species Only
• Non-use of Genetically Modified Organisms (GMO)
• Domestication to minimize disease concerns
• Hatchery
• Probiotics
• Growout Systems
• Advanced Technology
• Exposed Areas
• Strong currents and depth for effluent dispersion
• Feeds
• Efficiency
• Saturation of Oxygen increases FCR
• Fish are more efficient than terrestrial (dont
  fight gravity)
• Reduction of Fishmeal
• Pelletized diets with reduced fishmeal content
• Best Management Practices (BMP) development
• Environmental Assessment
• Water Quality Parameters Monitored

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Center for Sustainable Fisheries
www.rsmas.miami.edu/groups/aquaculture and/or
www.snapperfarm.com
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THANKS!
Grant No.DOC/NOAA/NSG NA 06 RG - 0068
AquaSense, LLC