Oysters Eastern oyster (Crassostrea virginica): European (flat) oyster (Ostrea edulis): Kumamoto...

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Transcript of Oysters Eastern oyster (Crassostrea virginica): European (flat) oyster (Ostrea edulis): Kumamoto...

Oysters• Eastern oyster (Crassostrea virginica):

• European (flat) oyster (Ostrea edulis):

• Kumamoto oyster (Crassostrea sikamea):

• Olympia oyster (Ostrea lurida):

• Pacific oyster (Crassostrea gigas):

Olympia oyster (Ostrea lurida

• The Olympia oyster is found from Alaska to Baja California, although Washington is the only state that has produced Olympias on a commercial scale. Overfishing and pollution have reduced catch levels to less than one percent of former levels. A few growers in Washington state have had some success farming Olympias, but production remains limited.

Pacific oyster (Crassostrea gigas)

• Comprises 98 percent of world farmed oyster production. Native to Japan, it is now farmed extensively in Washington state, British Columbia, Europe, and the Pacific Rim. Most growers use hatchery seeds and raise the oysters on the ocean bottom or on trays or ropes suspended in the water column.

 

              

                                     

              

                      

             

                  

              

                           

Purchase and Storing Tips

• If stored at 36-40 degrees F in a moist environment, oysters can be kept up to two weeks after they are collected, however, shelf life is shorter after spawning in the summer.• As a rule, Olympia oysters command the highest price, followed by European oysters, Kumamotos, Pacific oysters, and Eastern oysters. • By law, a live-oyster shipment must include identification of the oysters' origin and collection date; it is illegal to discard this tag sooner than 90 days after delivery.

PRODUCT FORMS:

•   LIVE. SHUCKED MEATS: Graded:

• Petite (250-400/gal.),• Extra Small (145-250/gal.)• Small (96-144/gal.)• Medium (64-95/gal.)• Large (64 and under)• FROZEN: IQF meats and on the half shell• SMOKED meats• BREADED

YIELD:

• 5-14%, depending on species and time of year (meat yield is lower after spawning).

SIZE RANGE:

• In shell: Pacific oysters—2 1/2 - 7 inches,• Eastern oysters—3 - 5 inches• Kumamotos—2 1/2 -3 inches• Olympia oyster—1/2 - 1 inch• European flat oyster—3 - 4 inches• Meats: 2/10 of an ounce to 2 ounces.

MARKET NAME(S):

• In shell oysters marketed under various regional names (Blue Points, Hama Hamas, Wellfleets, Snow Creeks, Fanny Bays, Icy Bays, Hog Island, Pearl Bay etc.) or by species name (Olympias, Flats, Kumamotos etc.)

WASHINGTON IN BRIEFStatistics

• Top 5 Agricultural Commodities (2002)                         • CommodityValue of receipts (thousand $) Percent of U.S. value

• Apples 977,508 63.3%

• Dairy products 671,040 3.3%

• Cattle and calves 614,385  1.6%

• Potatoes 478,166 5.8%

• Wheat 475,718   8.6%

• Oysters 30,500 70.%

Shellfish Nursery Rearing Systems

1: Oyster Seed on Cultch • Seed that has successfully settled on shell or tubes

is moved from setting tanks to nursery areas.• Nurseries can be intertidal or subtidal.

– Rearing oyster seed on an intertidal beach hardens the seed, reduces predation and fouling but steps must be taken to prevent seed drying or being damaged by intense sunlight when it is exposed to the air between high tides. Intertidal nurseries are usually between the 1.5 and 2.5 meter level.

                                                        

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Growing algae in special indoor tanks

Nursery Systems: Upwellers for Clam and Single Oyster Seed

 

                                                

 Outdoor setting

tanks at the hatchery

                                                      

Harvesting

Harvesting

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TRIPLOID OYSTERSTriploid Oysters are a new type of oyster produced during hatchery spawning by increasing the number of chromosomes, the genetic material found in all living things.

 

                                                                                                          

 

THE "ALL-SEASON OYSTER"Triploid Oysters have two important advantages over Diploids during their life cycle. In the Summer months when regular Diploid Oysters are spawny, Triploids remain firm, full and sweet. And they maintain this quality during the Fall, when spawned-out Diploid Oysters are watery and reduced in mass.

                                                                  

 

THE WORLD'S LARGEST OYSTER HATCHERYTo meet our growing need for consistent, high quality oyster larvae and seed, we developed our own Quilcene, WA hatchery beginning in 1978. Here, advanced technology, experienced technicians, and a superb natural environment have combined to make it the world's largest, with a capacity in excess of 30 billion oyster larvae per year. This same quality is now available to provide other growers worldwide with a variety of oyster and clam species, plus algae feeds, and various support services.

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