Sydney Rock Oyster

Aim
TBD

Risk of spreading disease and parasites to native species
There is no evidence of disease or parasites from this facility impacting native species (although Sydney Rock Oysters can be susceptible to diseases introduced from other estuaries).

Input and use of chemicals
Chemicals are not used to produce Sydney Rock Oysters. No antifouling is used on the infrastructure and chemically treated wood or tar is not used. The longline mesh bags that hold the farmed oysters are manufactured using UV stabilized plastics.

Management effectiveness
The management agency has in place effective biosecurity measures and the producer meets regulations and exhibits effective management of disease and parasites. However, there is a lack of publicly available evidence regarding regulatory compliance from the management agency.

Aim
TBD

Direct impact of infrastructure on habitats
The operation is in a seagrass dominated estuary, however the practice of using floating bags results in minimal effects on the habitats and ecosystems.

Near-field impacts of water and sediment pollution
Chemicals are not used in the processing of oysters. Oysters feed naturally in the environment through filter feeding on particulate matter which cycles nutrients to the seabed and increases water clarity, both of which encourage seagrass growth.

Regional impacts
Floating bag systems have minimal environmental impacts on seagrasses and no demonstrable impacts on sedimentation rates. Since replacing rack and rail infrastructure with floating bags, the impacts of shading on seagrass has been greatly reduced and seagrass coverage has been increasing.

Management Effectiveness
The regional planning, research and monitoring and compliance of the oyster industry is effectively managed by NSW DPI. Merimbula Lake Oyster Growers produced an Environmental Management System in 2011 to help guide environmental best practices. However, the EMS should be updated every 3-4 years.

Aim
TBD

Insignificant risk of wildlife interaction
There is no evidence to suggest, and it is unlikely, there is insignificant risk of wildlife interaction

Behavioural effects
Both fish and birds interact with oyster leases for feeding and refuge opportunities but this does not result in significant negative impacts to these species.

Entanglements and incidental mortality
There has been no reported entanglements of wildlife in the longlines that suspend the floating bags. Hollow large-diameter poles that could trap birds if they use to perch and fall inside, are not permitted.

Escapes, translocations and genetic impacts
As Sydney Rock Oysters are a native species in this estuary there are no issues regarding escapement. Broadcast spawning of farmed oysters is regarded as beneficial to the wild populations. Although a small proportion of selectively bred disease resistant spat are introduced to the estuary, there is no evidence of any genetic impacts on the wild populations.

Management effectiveness
As there does not appear to be any significant wildlife interactions, there are also limited management regulations by the management agency and no publicly-available evidence regarding compliance.

Aim
TBD

Ongoing reliance on wild stocks for broodstock, juveniles or feed
There is ongoing reliance on wild populations for juveniles

Wild stocks are sustainable
The majority of the source stock are collected from the wild, primarily in the neighbouring estuary, Pambula Lake. It is unlikely that the intensity of spat collection from Pambula Lake results in the depletion of wild stock.

Food is from sustainable sources
Supplemental feed is not used