Until recently, the industry has been totally reliant on an abundance of natural spat as its source of stock. The Sydney rock oyster grows and survives best in intertidal estuarine habitats such as rocks, mangroves, and man-made structures, but it also occurs subtidally on natural dredge beds. Main producer countries of Saccostrea commercialis (FAO Fishery Statistics, 2006) Habitat and biology The species also exists in New Zealand but is not farmed there. The genetics of the oysters in Shark Bay on the west coast and those farmed on the east coast in NSW and southern Queensland have not been fully compared. The Sydney rock oysters along the NSW coast do not differ genetically from each other. 37°S) on the east coast through temperate NSW, subtropical Queensland, across the tropical north and along the west coast as far south as Shark Bay in Western Australia (lat. In Australia, a continuous distribution of Sydney rock oysters exists from the Victoria/NSW border (lat. 35°S), far south of the limit of their natural distribution in Shark Bay (lat. The oysters are successfully farmed near Albany (lat. Since 1997, one company with its own hatchery in Albany, Western Australia (WA) has been successfully producing spat from a strain of Sydney rock oysters obtained from Shark Bay. When Pacific oysters were found in Port Stephens in 1984, the transfer of oysters to the northern estuaries was greatly restricted to prevent the spread of Pacific oysters further north. In autumn, large quantities of oysters were taken to the northern rivers of NSW for winter 'fattening' and returned to Port Stephens for marketing in spring. Highway oyster farming was particular prominent in Port Stephens, which produced a lot of spat that were taken by truck to other estuaries for growing. Production rates stabilised during the 1970's at around 13 million dozen (7 800 tonnes) per year. This practice, known as 'highway oyster farming', developed from the mid 1960s onwards. Much of this increase was attributed to the increase in the number of farmers who had decided to transport oysters from estuary to estuary to take advantage of differences in the timing of prime growing or fattening conditions. However, around 1970, production rapidly increased from about 10 to 14 million dozen or 6 000 to 8 400 tonnes (wet weight including shell). This was the dominant growing system from the 1950s till the 1990s and provided some protection against mudworm infestation.ĭuring the 1950s and 1960s the NSW Sydney rock oyster industry exhibited consistent growth as production methods improved and total lease area increased. The mudworm, Polydora sp., appeared in NSW concurrently with the introduction of New Zealand oysters, and farmers had to develop intertidal farming methods using sticks and trays. Around 1888, spat of oyster from New Zealand were imported into NSW to replenish depleted oyster stocks. Oyster cultivation began in New South Wales (NSW), Australia around 1870 when oyster farmers began to set out sticks, stones, and shells to catch and grow oysters in the intertidal zone until they could be harvested. Grows to 70 - 100 mm in shell height measured from hinge to lip. Outer fold of mantle white but middle and inner folds and the groove between are pigmented towards edges. Small denticles along edge, close together adjacent to hinge but further apart distally on upper valve. Muscle scars usually white but frequently having bluish or creamy markings, particularly on upper valve. Internal colour chalky white, with bluish black or sometimes brown border. External coloration of valves varies from bluish black to greyish white with indefinite blue-black borders. Hinge line moderately wide, ligament blue. Upper valve flattened, folded towards lip to fit crenulations of lower valve. Very variable in shape, lower valve deep and cupped, recessed under the hinge, moderately fluted, more strongly so in exposed positions, and valve edge weakly crenulated.
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