Transcript OPEN OCEAN AQUACULTURE: TECHNOLOGICAL AND ENVIRONMENTAL ISSUES Daniel D. Benetti Associate Professor Director, Aquaculture Program Division of Marine Affairs and Policy.

OPEN OCEAN AQUACULTURE:
TECHNOLOGICAL AND
ENVIRONMENTAL ISSUES
Daniel D. Benetti
Associate Professor
Director, Aquaculture Program
Division of Marine Affairs and Policy
“A new way to feed the world”
“Aquaculture is a good thing, in
spite of environmentalists concerns”
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
Cobia, Rachycentron canadum
Mutton Snapper, Lutjanus analis
Cobia, Rachycentron canadum
Greater amberjack, Seriola spp
Tuna, Thunnus spp
HATCHERY FOR R&D 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
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)
Cobia are shipped and stocked at 35-40 DPH @ 3.0-5.0 g and 7-10 cm
Harvesting, Transporting and Shipping Fingerlings
Add new slides with pictures from shipment to Eleuthera
Trucks, convoy, Boeing, etc.
Receiving and Transporting Fingerlings in Puerto Rico
ISLA CULEBRA, PUERTO RICO
Stocking the Offshore Cages
off Culebra Island, Puerto Rico
OFFSHORE SYSTEMS
SeaStation 3000 - Ocean Spar
Culebra Island,
Puerto Rico
South Eleuthera,
Bahamas
AquaSense, LLC
Cobia fingerlings are stocked in submerged nursery cages inside
SeaStations 3,000 m3 off Culebra Island, Puerto Rico,
and South Eleuthera, the Bahamas
STOCKING DENSITIES
20,000 fingerlings stocked/3,000 m3 cage (2,700 m3) = 7 fingerlings/ m3
20,000 fingerlings @ 90% survival = 18,000 harvest/market size fish (6 kg)
18,000 fish @ 6 kg/ea = 108.000 kg (108 Ton) / 2,700 m3 = 40 kg/ m3
GROWOUT
Pellets: AquaExcel 5310 (Burris): Extruded, slow sinking, 53% CP, 10% CF
FCR = 1.95 on pellets made of 50% fish meal
ENERGY CONVERSION: NATURE VS. OFFSHORE AQUACULTURE
NATURE - WILD
OFFSHORE AQUACULTURE
90% LOSS BETWEEN TROPHIC LEVELS OF THE FOOD CHAIN
1000 KG
1000 KG
PHYTOPLANKTON
PHYTOPLANKTON
100 KG
100 KG
ZOOPLANKTON
ZOOPLANKTON
10 KG
10 KG
ANCHOVIES
ANCHOVIES
{
20% DRY
1 KG
SALMON
Fish Meal
Fish Human Cons.
2.2 times more
efficient in
producing
COBIA/
FISH ARE 20% DRY (80% MOISTURE)
THEREFORE THE FCR IN NATURE IS
10:1 (WET:WET) or 2:1 (DRY:DRY)
MOI/
SALMON!
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
=
(90% dry, 10% moisture)
1.8 kg dry pellet
1 kg cobia (wet weight)
(80% moisture, 20% dry)
=
0.2 kg dry cobia
=
0.2 kg dry cobia ; 0.9 / 0.2 = 4.5; Pellet efficiency = 4.5 : 1
(50% fish meal)
0.9 kg dry fish meal
Nature “Efficiency”:
Pellet “Efficiency”:
10 : 1 (wet or dry weight)
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
Transformation Efficiency
1)
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.
2)
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.
3)
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.
4)
The actual whole pellet efficiency is 9 : 1.
5)
This is the whole pellet (fish meal, grains, etc.) efficiency, not just the fish meal’s.
It's like the whole pellet is contaminated with material that's not fish meal
(in this case, mostly cheap grain fillings).
6)
@ 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).
Transformation Efficiency in Percentages (%):
1) Nature = (1/10) * 100% = 10%
(10% of biomass ingested as menhaden transformed in “new” cobia biomass)
2) Dry Fish Meal = (0.2 / 0.9) * 100% = 22%
3) Pellet Efficiency (fish meal + fillings) =
(0.2 / 1.8 * 100% = 11%
Environmental assessment
• 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
• Biological factors
–
–
–
–
–
–
Fouling
Chlorophyll
Productivity
HABs
Assemblage
Benthic studies
• Chemical factors
–
–
–
–
–
–
–
–
Total suspended solids
Ammonia
Nitrite
Nitrate
Phosphate
Dissolved oxygen
Organic matter
Nitrogen
• Socio-economic studies
– Acceptance of project
– Local communities
– Partnership Fishermen Association
• Educational component
– Elementary / High School /
Technical Level Curricula
– Teachers’ Materials / Talks, etc.
Sampling Protocol
Fig. 1. Dissolved nutrients at the cages and the control site
Snaper
Cobia
Control
0.040
0.035
0.030
mg/L
Preliminary Results
0.025
0.020
0.015
0.010
0.005
0.000
Ammonia
Nitrite
Nitrate
Phosphate
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
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 (P<0.05) 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
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
Observations Relative to Specific Criteria
(Based on Hawaii Administrative Rules, Title 11,
Department of Health, Chapter 24,Water Quality Standards)
Observations
Total # of observations – 373 Geometric mean Not to exceed Maximum value
not to exceed the more than 10% observed and
given value
of the time
Number of
Parameter
Occurrences ( )
Total Nitrogen mg N/L
150
250
>150 to 250 (2)
Ammonia Nitrogen mg NH4/L
3.5
8.5
> 8.5 to 69 (9)
>3.5 < 8.5 (32)
Nitrate + Nitrite N mg (NO3+NO2)/L
5.0
14.0
always < 5
20.0
40.0
>20 <31 (1)
> 40 (0)
Total Phosphorus mg P/L
pH 8.2+/-0.05; Temperature + 0.5oC from ambient; Salinity 35+/-0.5; D.O. >80%
Helsley et al. 2003
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
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
10000
2
2
y = 0.0626x - 2.7743x r = 0.90
9000
8000
Weight (g)
7000
6000
5000
4000
3000
2000
1000
0
0
50
100
150
200
250
300
350
Age (Days Post Hatch)
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
400
10000
y = 7988 * (1-(exp(-0.0096(x-92)))^3)
9000
2
r = 0.88
8000
> 95% mature
Weight (g)
7000
Onset of maturation
6000
5000
4000
3000
2000
1000
0
0
50
100
150
200
250
Age (Days Post Hatch)
300
350
400
450
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)
Comparative Growth of Cobia in Offshore Cages in
Puerto Rico and The Bahamas
T o ta l le n g th (m m )
Cobia growth in length
60.0
50.0
40.0
y=-0.0009x
2
y=-0.0021x
2
+0.483x-8.48 r
2
=0.95
+0.727x-24.2 r
2
=0.91
30.0
20.0
10.0
0.0
0
20
40
60
80
100
120
140
160
Age (dph)
Squares - Snapperfarm, Puerto Rico @ 27-31 oC
Circles - AquaSense, South Eleuthera @ 22-25 oC
Cobia growth in weight
1400
W e t w e ig h t ( g )
1200
y=0.082x
2
y=0.027x
2
-7.11x+159.8 r
-0.431x-54.4 r
2
2
=0.87
=0.80
1000
800
600
400
200
0
0
20
40
60
80
Age (dph)
100
120
140
160
Preliminary Data
Q10
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 (SD=2.4; CV=39%)
or 13.3 lb [1.7-9.1 kg]
FCR = 1.95
Survival > 90%
18 months (1.5 yr) from eggs:
Total Feed: 52,255.20 kg
Total Morts: 663
Harvested: 2,175
Estimated remaining: 100’s
Average weight: 7.75 kg (17.06 lb) [5-16kg]
FCR = 2.29
Survival = 75%
Total biomass harvested: 15 Ton (< 33,000 lb)
Total number of fish: 3,200…
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)
BIOFAULING!
Pros and Cons
Panulirus argus
HARVESTING AND SHIPPING - HIGH-END MARKET
MARKET
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, NGO’s, press and public at large:
native species; no GMO’s; probiotics; only
FDA approved chemicals (except food additive
eugenol); adv. growout technology; exposed sites
offshore; high efficiency feeds, low FCR, reduce
use of fish meal; no drugs, chemicals, ATB’s,
hormones, pigments - all natural, “organic”(?);
environmental monitoring H2O/benthos
• Overall assessment:
Technologically feasible
Environmentally sustainable
(low impact)
Economically viable once expanded
Addressing Industry Needs as well as
Concerns of Agencies, NGO’s, 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 (don’t fight gravity)
– Reduction of Fishmeal
• Pelletized diets with reduced fishmeal content
• Best Management Practices (BMP) development
•
Environmental Assessment
– Water Quality Parameters Monitored
• Water Column
• Benthos
• Biodiversity
OFFSHORE AQUACULTURE
Center for Sustainable Fisheries
CONCEPTUAL OFFSHORE SUSTAINABLE AQUA
FARM
www.rsmas.miami.edu/groups/aquaculture and/or www.snapperfarm.com
THANKS!
Grant No.DOC/NOAA/NSG
NA 06 RG - 0068
AquaSense,