Oyster Culture in Georgia: Growout - PowerPoint PPT Presentation

1 / 16
About This Presentation
Title:

Oyster Culture in Georgia: Growout

Description:

supplemental fishery- clammers, crabbers harvest oysters by manually ... spat on these sticks, perform regular culling to ensure fast growth and regular shape ... – PowerPoint PPT presentation

Number of Views:42
Avg rating:3.0/5.0
Slides: 17
Provided by: ValuedGate1326
Category:

less

Transcript and Presenter's Notes

Title: Oyster Culture in Georgia: Growout


1
Oyster Culture in GeorgiaGrowout Marketing
  • Alan Power, Ph.D.
  • Marine Extension Service
  • Shellfish Research Laboratory
  • University of Georgia
  • 20 Ocean Science Circle
  • Savannah, GA 31411-1011
  • Tel (912) 598-2348

2
Georgia Oyster Fishery
  • Eastern Oyster, Crassostrea virginica
  • 1908 Georgia led country in landings
  • today virtually non-existent
  • supplemental fishery- clammers, crabbers harvest
    oysters by manually gathering intertidally, break
    clumps up, labor intensive, poor appearance

3
Georgia Historical Oyster Landings
Ibs Raw Meat
Value ()
200,000
180,000
160,000
140,000
120,000
100,000
80,000
60,000
40,000
20,000
0
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
4
Oyster Culture Techniques
Bags on Racks
Stick Culture
Trays
Rafts
Long Line
British Columbia Shellfish Growers Information
Resource System www.bcsga.ca/bcsgirs/main/sgmain.h
tm
5
Half Shell/ Shucking/ RoastProduction Cycle
  • half shell requires single seed
  • nursery upweller, bags, trays
  • growout subtidal (LL/R)- trays, bags
    intertidal- bags on racks
  • shuck/ roast product from cultch set seed
  • nursery subtidal (LL/R)- trays, bags
    intertidal- bags, sticks
  • growout subtidal (LL/R)- sticks, string shell
    cultch intertidal- bags, sticks

6
Oyster Culture in GeorgiaWhy Why Not?
  • Advantages
  • market size (3) in 18 mo. vs 3 years north
  • not spat limited
  • unpolluted grow out areas
  • Problems
  • oyster spat- densely packed clumps
  • long spawning season- poor meat yields
  • markets long narrow oysters not suitable for
    shucking or half shell trade
  • small home market- local oyster roasts

7
Oyster Spat Fouling Problem
  • overabundant spat- problems growing in floating
    rafts, intertidal trays, or suspended subtidally
  • recruitment in Georgia- May to Oct
  • spatial and temporal variability
  • 300-7600 spat m2/mo., peak July-Sept
  • higher subtidally than intertidally
  • higher in smaller sheltered tidal marsh creeks
    than more open water areas

8
Possible Solutions
  • triploid oysters
  • grow faster reach size before recruit?
  • lower market size
  • 3-size at maturity up north, here in 1st yr
  • would be cleaner but marketable?
  • alternative culture techniques
  • transplant during recruit. period
  • regular thinning and spat killing
  • new technology- Oysterclear/Freshwrap

9
TransplantingShellfish Lab Experiments
  • collect spatfall (or obtain single spat from
    hatchery) after peak recruit. period, grow in
    floating trays/ upweller/ suspended intertidal
    mesh bags
  • transplant to areas of lower recruitment during
    spawning season
  • to bags placed intertidally on the bottom
  • to areas far up tidal creeks where oyster cover
    is low (high tidal flushing rates)

10
Thinning Spat RemovalQueensland Australia
  • collect natural spatfall after peak recruit.
    period with oystersticks
  • grow spat on these sticks, perform regular
    culling to ensure fast growth and regular shape
  • during subsequent recruitment period remove
    excess spat manually or by a 3 second immersion
    in water heated to 82oC

11
OysterclearNew Australian Product
  • Wattyl Protective Marine Coatings
  • http//pcm.wattyl.com.au
  • protective coating for oyster shell
  • inhibit spat and other fouling
  • hot melt coating, dip oyster, dries immediately,
    back in water
  • oyster grows, areas exposed,however fouling more
    severe on older areas
  • during harvesting coating falls off
  • non toxic, not antifoulant, food based

12
Summary GA Possible Culture Techniques
  • collect spatfall after peak/ obtain single spat
    from hatchery at this time
  • grow in upweller/floating trays/bags
    (subtidally), or on collection sticks/mesh bags
    (off bottom intertidally)
  • transplant up tidal creek/on bottom
    intertidally/kill excess spat with hot water
    dips/cover in protective oysterclear during
    next recruit. event.
  • harvestwinter fatter summer triploids

13
MarketingGulf Outlook
  • Sept. 02 Seafood Business
  • Gulf production, price outlook good everywhere
    except Texas
  • Louisiana- increase in farmed oysters
  • Mississippi- production on upswing
  • continued strong demand- price increase for Gulf
    oysters (4.50-5.50 a pound for meats)
  • market for IQF oysters on halfshell grown rapidly
    (25-30 cents a piece), also pressure treated
    oysters (35 cents)

14
MarketingWest Coast Outlook
  • Sept. 02 Seafood Business
  • West Coast market for live oysters never better
  • live price remains stable (2.75-4 a dozen)
  • market for shucked meats weak
  • price fallen 20 percent last year

15
MarketingIs There a Demand?
  • Feb. 03 Seafood Business
  • identify a need to increase supply to meet
    demand- Gulf harvest down 60, Ches. Bay down,
    Pacific Coast stable, imports stable
  • particular demand for boutique oysters high
    quality, names and flavors reflecting local
    harvest areas
  • promotion NB, e.g. regional oyster festivals-
    Oyster Olympics

16
Marketing Summary
  • demand for high quality half shell oysters
  • raw meat market dominating through cryogenic
    freezing/ pressure treating to reduce vibrio
  • increase home roast market through promotion-
    2001 SC vs GA
  • 257,568 lbs. meat, 1,066,578 versus
    8,528 Ibs (1/30th), 22,254 (1/50th)
Write a Comment
User Comments (0)
About PowerShow.com