FAQs
		Frequently asked questions about Sydney rock oysters.

History When Captain Phillip arrived in Sydney Harbour in 1788 the Aboriginal population had been harvesting the native oysters for centuries. These oysters grew naturally on the rocks of estuaries along the eastern Australian coastline, from Wingan Inlet in eastern Victoria to Moreton Bay in Queensland. These native oysters are known as Sydney rock oysters (saccostrea glomerata). Life Cycle The Sydney rock oyster changes sex many times during its life. Most, if not all spawn as males and change to females later in life. During spawning adult oysters shed millions of sperms or eggs into the sea. Spawning is so intense that the water can take on a milky appearance. After spawning the oyster regains prime condition over the following weeks. Fertilization takes place in the water and for up to three weeks the larvae swim and grow and ultimately settle on hard substrates. The oyster is now called a spat and this spat will grow to a marketable oyster, about 70mm long, in 3-4 years time.

	Cultivation Commercial cultivation of Sydney rock oysters commenced around 1870. Generally, the NSW oyster industry utilises the abundant natural settlement of Sydney rock oyster spat and cultivates it to maturity, rather than relying upon hatchery reared spat. It takes about 4 years to produce a marketable Sydney rock oyster.
				Various types of spat catching materials
	Hatchery-reared spat (as used with Tasmanian and South Australian pacific oysters) have been adopted by parts of the Sydney rock oyster industry where there is a cost advantage over naturally caught spat.

							Traditionally Sydney rock oysters are caught on sticks, then grown out on the sticks, on racks, at the mid tide region of various estuaries.
		Increasingly, industry is removing young spat from various catching surfaces and growing them on as individual oysters. These individual oysters are placed on trays, which provide optimal growing conditions and can lead to a better shape and quality in the oyster.
			The racks on which oysters are grown are owned and developed by oyster farmers who lease the oyster farming areas from the NSW Government. Commercial production in NSW occurs between Eden in the south and Tweed Heads in the north. Sydney Rock oyster production for 1997/8 is estimated at A$31 million at farm gate from 9.2 million dozen oysters.
	Quality Assurance NSW leads the world in technology to assure the quality and purity of cultivated oysters. All oysters in NSW are harvested in accordance with the NSW Shellfish Quality Assurance Program which encompasses an ongoing strategic water and meat sampling program. This information, combined with an understanding of the farming environment, and the appropriate use of controlled purification, offers a comprehensive system of quality assurance.
	Preservation and Presentation Sydney rock oysters will live out of water and remain in prime condition for up to two weeks if kept out of direct sunlight in cool, moist conditions. By comparison, the pacific oyster may only remain alive for a few days out of water. Sydney rock oysters are best eaten freshly opened on the half shell. The French use a drop of lemon juice on the opened oyster to assure themselves that it is still alive and fresh by watching the muscular reaction to the acidic lemon. If it is not convenient to serve the oysters immediately upon opening, they can be refrigerated up to three days without any significant deterioration in condition or visual appeal. However, the half shelled oysters must be kept below 4°C and prevented from drying out. Opened oysters are perishable like any other type of fresh fish, and should not be kept without refrigeration or refrozen once thawed.
	Oysters in your Diet Folk lore indicates that Sydney rock oysters have significant aphrodisiac effects. Whether this is fact or fiction is for you to determine. Few foods can compare with oysters in terms of their nutritional value. The oyster is a well balanced, easily digestible, nutritious food, rich in minerals and vitamins such as omega-3, zinc, iron, vitamin A, B1, B2 and C.
	Sydney rock oysters have very little cholesterol, and contain approximately one quarter that of prawns and squid and equal to most fish. Sydney Rock oysters are well below the cholesterol levels found in red meats and duck. ...Bon appetite