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Sydney Rock Oysters

1 February 2023

The Sydney Rock Oyster (Saccostrea glomerata) is a bivalve mollusk and is Australia’s only native rock oyster!

It is found in the Port Stephens Estuary and while many Port Stephens locals find oysters to be delicious to eat, they also perform an incredibly important function for their local ecosystems. Oysters are filter feeders, they feed upon suspended particles in the water column helping to keep nutrient loads down and improve water quality. Their oyster reefs also provide habitat for fish and other invertebrates, helping to create a diverse ecosystem.

Just how important the Sydney Rock Oyster is to the health of the Port Stephens Estuary can be seen in the results of the Port Stephens Oyster Reef Restoration project. The project involved the construction of rock bases across 7.5 hectares of bare sand and mud in the Port Stephens-Great Lakes Marine Park and was conducted by DPI Fisheries and funded under MEMS (Marine Estate Management Strategy).

More than 55 million baby oysters (called oyster spat) were colonized on the reef base to create a living and growing oyster reef. It has now been 2 years since the reef restoration began and researchers have already seen significant changes taking place in the vicinity of the reefs including an increase in species diversity and type. Plus, they have calculated that the restored reefs are filtering the equivalent of 3 Olympic swimming pools of water every hour!

Unfortunately, Sydney Rock Oysters reefs are susceptible to disease, invasive species, poor water quality and overfishing. The extent of their reef beds has been significantly reduced as a result of these threats. Therefore, the Port Stephens Reef Restoration study is not only hugely promising in restoring ecosystem health and function but in increasing the numbers of the Sydney Rock Oyster.

Read more about the Port Stephens Oyster Reef Restoration project here.

To see the more about the Coastal Management Program visit