OFFSHORE AQUACULTURE OF MARINE FINFISH IN THE CARIBBEAN

Daniel Benetti*, Refik Orhun, Brian O’Hanlon, Larry Brand, James Collins, Christopher Maxey, Andy Danylchuk, Dallas Alston, Alexis Cabarcas

Cobia, Rachycentron canadum

Carangidae (jacks and pompanos)

Mutton Snapper, Lutjanus analisCobia (Rachycentron canadum)

Yellowfin Tuna, Thunnus albacares

SPECIES CRITERIA

1) Native /endemic to the region (SE US,Gulf and the Caribbean)

2) High market demand and value

3) Technology developed/available fromegg to market (hatchery produced)

4) High Aquaculture performance:Growth Survival Feed conversion rate

Cobia (Rachycentron canadum)

Comparative Growth During Early Developmental Stages45 DPH (Days Post Hatch) – 6 weeks

Cobia5.5 g; 11.5 cm (4.5 in)

Snapper0.2 g; 2.0 cm (1.0 in)

Which species would you rather select for commercial aquaculture?

BROODSTOCK MANAGEMENTTechnological Advances:• Large (50-80 ton) independent, environmentally controlled recirculating systems• TEMPERATURE control is KEY for natural spawning• Improved nutrition [fish, squid, shrimp, pellets, blood worms (polychaetes)]• Improved handling [no handling or using clove oil (eugenol) @ 10-20 ppm]• Removal/addition of individuals (aggressive males/females, stress, sex ratio)• Use of artificial substrates mimic sea grass beds (Aquamats)• Parasite control (“cleaning station”, symbiosis, neon goby, Gobiosoma oceanops)

When exposed to correct temperature cycle,cobia spawn naturally at ≥ 24 oC (optimum is 26 oC!?)

HATCHERY TECHNOLOGY OF COBIA Rachycentron canadum

45 days old (4.5 in)20 days old

10 days old

Yolk-sac larvae - 1 day old

HATCHERY TECHNOLOGYIntensive and Extensive Larval Rearing in Tanks and Ponds

Fist trials carried out at the University of Miami Experimental Hatchery inMay/June 2005 produced tens of thousands of healthy cobia fingerlings

Shipping ChallengesLogistics

San Juan, Puerto Rico

Rock Sound, South Eleuthera, Bahamas

Fajardo, Puerto Rico

Stocking Snapperfarm’s SubmergedCages off Culebra Island, Puerto Rico

SeaStation 3000 - Ocean Spar, Net Systems (U.S.)

Culebra, Puerto RicoSnapperfarm, Inc.

Eleuthera, BahamasAquaSense Bahamas, Ltd.

H2O flow > 2 billion liters/day(>600 million gl/day)

Cage volume = 3000 m3

Average current velocity = 0.5 knotDepth = 25-30 m (90-100 ft)

Cobia juveniles are transferred from the nursery cage into3,000 m3 SeaStation main cages in 2-4 weeks in

Puerto Rico and South Eleuthera, Bahamas

Stocking densities: 3,000 - 20,000 fingerlings @ 70-90% survival; harvest @ 12-8 lb (6-4 kg) eaSeaStation 3000 = 2700m3 volume = 15 - 70 Tons/cage = 5 - 25 kg/m3 or 12-50 lb/m3

Market Price of Fish (whole gutted) = $ 3.25 - $ 4.0/lb or $ 7.15 - $ 8.8/kg

Snapperfarm and AquaSense cobia areproduced without the use of antibiotics, hormones, pigments, or pesticides.Grown offshore, far from pollution sources

Organic Cobia!?[Ethoxyquin, a synthetically-derived antioxidant(stabilizer) used to prevent oxidation, rancidity.]

GROWOUT

Extraordinary Rates of Growth and Feed Conversion Efficiency (FCR)

at Low Environmental Impact

Recorded and fitted Van Bertalanffy growth of cobia (Rachycentron canadum) in Snapperfarm’s offshore cages off Culebra, Puerto Rico

from hatching to 14 months

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y = 7988 * (1-(exp(-0.0096(x-92)))^3)

r2 = 0.88

Onset of maturation> 95% mature

COMPARATIVE GROWTH RATES OF COBIA CULTURED IN OFFSHORE CAGES UNDER DIFFERENT TEMPERATURES AND STOCKING DENSITIES

Cobia growth in weig

Eleuthera - y = 0.0246x2 - 1.0583x + 87 r2=0.81Culebra - y = 0.0264x2 + 6.3234x + 87 r2=0.69

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GROWTH RATES OF COBIA CULTURED IN OPEN OCEAN CAGES IN PUERTO RICO AND THE BAHAMAS

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Environmental and economic sustainability of operations?

Lower stocking densityHigher temperature

Higher stocking densityLower temperature

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COBIA PRODUCTION IN CAGES - SENSITIVITY ANALYSIS

Cage Volumes 3000 & 5400 m3

Flip Cages

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 factors– Acceptance of project– Local communities– Partnership Fishermen Association

• Educational factors– Elementary / High School / Technical

Level Curricula– Teachers’ Materials / Talks, etc.

Dissolved nutrients in the water column

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Snapper Cobia Control

4.76 4.68 4.75

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Organic matter in the sediments at the cages and control site

Environmental AssessmentSummary of Results - Puerto Rico

Environmental AssessmentSummary of Results - Bahamas

Average Water Column Chlorophyll aNovember 2003 - December 2004

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Average Benthic Chlorophyll-aNovember 2003 - December 2004

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Summary of Environmental Studies (Puerto Rico, Bahamas, Hawaii, New Hampshire)

• Environmental data from Puerto Rico and the Bahamas indicate that there are no significant changes in the water column and benthic ecosystems near the area.

• There were no significant differences in any of the water quality parameters measured in the area surrounding and beneath the cages.

• No samples had values in excess of allowable values under the NPDES permits

• Data are from small scale, demonstration projects

• Need to continue environmental monitoring studies as operations expand to determine whether/when a threshold level may occur

Benetti, Brand, Helsey, Langan, Alston, Cabarcas, Collins (in prep)

Cage Location

HURRICANES

• In 2004, the cages were exposed to severe storms, including category 4 Hurricane Frances

• WINDS ranging from 70-100 miles/hr

prevailed in the area where one of the cages is deployed in South Eleuthera for almost 24 hours

• No damage to the cage or fish

mortality were observed

SHARK PREDATIONESCAPEMENTS

PROBLEMS:

HARVESTING/PROCESSING/SHIPPING

HIGH-QUALITY PRODUCT…

… FOR A HIGH-END MARKET

• Objective is to produce high-quality fish for high-end market seeking profits and lowering US seafood trade deficit ($ 8B)

• New technology has been developed from egg to marketNew species, increase production to market

• Results suggest that growing this species in exposed sites canproduce high yields of fish with low environmental impact

• Results suggest that, properly sited and managed, aquaculture of high-value fish can be conducted responsibly

• It will be difficult to compete with production from abroad (Asia, L.A.);environmental/technological prospects great; economic prospects not

SUMMARY

• Anti-predator systems including predator nets, shark pods, electromagnetic fields and chemical/electrical repellants,improvements on existing cage design, new cage design

• Get funding (government and private) and permits to expand operationsto reach economic feasibility

• Continue environmental monitoring studies to ensure environmentalsustainability and determine threshold

• Expansion of offshore aquaculture will be driven by economic andenvironmental concerns combining the needs from the industry,government agencies, NGO’s, press and the public at large

• Move/develop the industry abroad with great losses (e.g. qualitycontrol, employment, social/economic losses, dependence foreignproduction; seafood trade déficit)

SUMMARY - THE FUTURE

OFFSHORE AQUACULTURE

CONCEPTUAL OFFSHORE SUSTAINABLE AQUA FARMhttp://www.rsmas.miami.edu/groups/aquaculture - www.snapperfarm.com

OPEN OCEAN AQUAFARM - NOT JUST A CONCEPT ANYMORE…

THANKS!

Aquaculture Research Council - ARC