2019-01-14 General Committee Agenda - Attachment 3 to Item 2 - Monitoring of Noosa River Oyster Reefs Nov 2018

Introduction and context
Oyster reef restoration in the Noosa River;
The principal objective of the Noosa River Oyster Reef Restoration project is to restore
natural oyster reef habitat in the Noosa Estuary. This requires the addition of suitable hard
substrate for oyster spat to settle, and allowing natural recruitment and reef-formation
processes to recover to areas that historically supported oyster reefs.

The oyster settlement substrate comprises oyster reef restoration units. These units are
made from the most suitable recruitment material - oyster shells held together by a natural
coir fiber bag. The units are raised above the muddy and sandy marine substrates, thereby
mimicking the vertical relief of the original oyster reefs to facilitate natural recruitment
processes (Figure 1, 2). We expected that natural recruitment processes would cement the
dead shell together and form part of the mosaic of habitats within the estuary including both
soft and hard structural habitat types, thereby creating a structurally diverse mosaic of
habitats that is predicted to be beneficial to a range of fish species, including species of
harvested in commercial and recreational fisheries (e.g. yellowfin bream, estuary cod, tailor,
mangrove jack, and moses perch).

The restoration sites that were chosen as locations for oyster reef restoration in the Noosa
River (Figure 3) because they:
   1) are in reaches of the lower Noosa River estuary and in Weyba Creek from which
        oysters were harvested historically;
   2) are within the depth range known to be suitable for oyster reefs to grow;
   3) are in locations where viable oyster larvae were recorded during recent recruitment
        studies; and
   4) have an extent where the final restored area will not exceed the historical areal
        extent of oyster reefs before commercial harvesting took place.




Figure 1 Coir mesh bag filled with recycled oyster shells; the principle restoration unit




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