intensive and extensive oyster aquaculture

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