Intensive and Extensive Oyster Aquaculture

A.J. ErskineBevans Oyster Company

Cowart Seafood CorporationJuly 6th, 2012

CORPORATION

COWART SEAFOOD

VIRGINIA BEACH

BEVANS

COWART

ATLANTIC OCEAN

CHESAPEAKE BAY• Low salinity ~10-14ppt• Lower disease mortality compared to higher salinity regions

Potomac

River

OUTLINE

Why aquaculture? Development Dual approach Future

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

‘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

OYSTER AQUACULTURE

Intensive (containerized, protected, single seed):- high labor- high cost- high return

Extensive (planted loose, clustered seed):- low labor- low cost- low return

INTENSIVE AQUACULTURE

Set larvae on finely ground

shell

Plant loose in cages

Stock in nursery/FLUPSY

14 -21day larval period

FLoating UPweller SYstem (FLUPSY)

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

EXTENSIVE AQUACUTLURE

Traditional harvest

Plant on bottom

Set larvae on shells

14-21 day larval period

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

Phase III--Hatchery

Future

• Continue to expand intensive and extensive operations

• Continue to refine hatchery operation• Management of nuisance species—cownose

ray