Choosing a site for an oyster farm

Environmental impacts

Before issuing an authority, Fisheries Queensland assesses oyster areas to determine any likely environmental impacts on oysters. If these areas are inclined to be influenced by sewage, stormwater run-off, industrial pollutants or other influences that are considered detrimental, the authority will not be issued.

Fisheries Queensland runs a water quality program for commercial oyster-growing areas in the Moreton Bay area. The program monitors heavy metals, biotoxins (toxins produced by some phytoplankton species) and bacterial contamination (in particular, coliform bacteria species).

Growing areas

Growing areas are classified according to the criteria above. The classification is based on the amount, and type, of pollutant impacts on the various growing/oyster areas. From these classifications, Fisheries Queensland then determines:

• suitability of the area for growing oysters
• harvesting criteria
• any restrictions that may be placed on the growing/oyster areas.

Some areas that are suitable for spat production may not be suitable for fattening. Relaying, which involves moving stock from one area to another, can overcome the problems associated with poor fattening areas.

Other factors, such as the availability of suitable growing areas, may pre-determine the methods used for culture. Many estuarine areas tend to use racks and trays whereas offshore areas with vast tidal flats are more suitable to BST longline systems. In general terms, no single set of conditions can dictate the suitability of a site for oystering.

Oyster banks should not be exposed to strong currents or wave action under normal tidal conditions or during times of flood. Areas that are prone to shifting sand or sediment can also be problematic. These adverse conditions place additional stress on the oyster furniture, damage oysters, and make working these areas difficult. Some balance must be struck between currents and tidal flows to ensure that they supply the oysters with suitable water that is a nutrient-rich food source. The substrate should be firm enough to walk over, and to work on, although this is not always the case.

Offshore areas may be problematic if they are not close to a suitable land-based facility and long distances must be travelled each time stock is to be placed or maintenance carried out. Access to markets also needs to be considered, particularly when moving live stock to be processed.

Maturing areas

Through trial and error, the oyster grounds in the western part of Moreton Bay (in particular the estuaries) are the best areas for fattening oysters.

Estuary systems are particularly good at producing the populations of phytoplankton that oysters predominantly feed on. As oysters are filter feeders, the selection of maturing grounds is very important to avoid possible contamination. Commercial oyster culture is managed under strict environmental guidelines designed to ensure that oysters are only grown in areas with appropriate water quality.

Also consider...

• Find out how to get started in aquaculture.
• You will need to discuss technical and licensing aspects of any proposed aquaculture venture with staff from Fisheries Queensland and the Department of Environment and Science before proceeding with site selection, design and, where applicable, land purchase.
• Read our policy for maximising rock oyster production.
• The oyster industry management plan for Moreton Bay Marine Park supports the sustainable development of the commercial oyster industry in Moreton Bay.
• Find out how to prevent, identify and manage disease in aquaculture farms.
• Download the latest report to farmers for aquaculture industry statistics and production data.