FAQ

Oyster farming

Sydney lies in the centre of some of the best oyster-producing regions in the world, from Port Hacking and the Georges River to Broken Bay. The commercial cultivation of Sydney rock oysters began only in 1872. Early European settlers had taken to the local product with gusto, but they also burned the shells to produce lime for mortar. This depleted the natural population, so the government banned the burning of oysters for lime, leading to deliberate farming.

The first type of oyster farming was the French method, using canals. This was unsuccessful because the canals soon silted up and there was high heat kill in summer. In 1888 a severe infestation of shell-boring mud-worms, which thrive if oysters are partially silted, seriously affected the industry. This forced the development of intertidal farming techniques for catching and raising oysters. One method involved the use of materials such as stones and shells, known as cultch, placed on raised beds where the water flow was sufficient to enable the control of silting. A variation was to use stakes, cut from casuarina or mangrove trees, inserted vertically into the sediment. Stake cultivation has gradually developed into the modern stick and tray method.

Today Sydney rock oysters still account for 94 per cent of edible oyster production in New South Wales. Annual production, which was fairly stable in the last three years of the twentieth century, at around 7.9 million dozen a year, fell to 7.4 million dozen in 2001–02. Producing about eight million dozen oysters a year on average, New South Wales accounts for 60 per cent of Australia's oyster harvest. The value of production in 2001–02 was $29.6 million at the farm gate. State production peaked at about 14.5 million dozen in the 1970s, with declining output linked to poorer water quality. In the 1990s the aggressive QX disease decimated the Georges River oyster industry