Intensive and Extensive Oyster Aquaculture A.J. Erskine Bevans
Oyster Company Cowart Seafood Corporation July 6 th, 2012
CORPORATION COWART SEAFOOD
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VIRGINIA BEACH BEVANS COWART ATLANTIC OCEAN CHESAPEAKE BAY Low
salinity ~10-14ppt Lower disease mortality compared to higher
salinity regions Potomac River
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OUTLINE Why aquaculture? Development Dual approach Future
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REASONING Readily available local product Protection from
cow-nose ray predation Improved shucking yield Commercial-scale
volume for shucking at specific times of the year
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PHASES Phase I : Commercial-scale development of seed nursery
for intensive culture Phase II : Mechanization of nursery and
development/mechanization of grow-out system for intensive culture.
Development of extensive culture system. Phase III : Design and
implementation of commercial- scale hatchery
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OYSTER AQUACULTURE Intensive (containerized, protected, single
seed): - high labor - high cost - high return Extensive (planted
loose, clustered seed): - low labor - low cost - low return
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INTENSIVE AQUACULTURE Set larvae on finely ground shell Plant
loose in cages Stock in nursery/FLUPSY 14 -21day larval period
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FLoating UPweller SYstem (FLUPSY)
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CULTCHLESS SEED OYSTERS Oyster larvae obtained directly from
hatchery (triploid) 4-8 weeks in FLUPSY to one inch in size Planted
in seed cages Transferred to grow out cages in early spring
Maintenance coincides with splitting/harvesting Harvest within
12-18 months
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EXTENSIVE AQUACUTLURE Traditional harvest Plant on bottom Set
larvae on shells 14-21 day larval period
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CULTCHED SEED OYSTERS Oyster larvae obtained directly from
hatchery (diploid/triploid) Set on whole oyster shells in large
tanks Held in tanks for ~10-14 days Planted loose on bottom; no
maintenance Harvest between 18-24 months
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Phase III--Hatchery
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Future Continue to expand intensive and extensive operations
Continue to refine hatchery operation Management of nuisance
speciescownose ray