2015-11-10 - P&O Agenda - Item 7, Attach 2 - Assessment of Oyster Recruitment

system could have positive benefits for the estuary through increased protection of banks,
increased biodiversity and potentially increase the recreational fisheries productivity
(particularly for reef loving species such as bream) as it has done in other estuaries in the
Eastern USA (Cohen et al. 1999; Brumbaugh et al. 2006; Schulte et al. 2009).


4.2 Recommendations
Recommendations based on the results of this assessment of recruitment for the design of
any artificial reef structure in the Noosa Estuary include:

            Incorporating a variety of surface orientations particularly horizontal surfaces
             designed to maximise overhanging areas to ensure that recruits are not
             smothered by sediment and algal growth. Recruitment occurred on lower
             horizontal surfaces despite being places in locations with high rates of sediment
             deposition such as Lake Doonella.
            Locating the reef in an area where it will not interfere with normal vessel
             movement through the estuary (i.e. outside main channels, primarily along the
             banks).
            Locating the reef in an appropriate depth of water – oysters recruited in both
             intertidal and subtidal depths to <1.5 m deep, although the greatest total number
             were found intertidally approximately 0.1-0.2 m above the Low Tide Mark.
            The success of any oyster reef reintroduction program will likely be maximised by
             locating reefs in the main estuary around Tewantin, in the narrow channel
             between Goat Island and Noosa North Shore, or in Weyba Creek.
            Timing the deployment period to coincide with period of maximum recruitment
             potential (summer to autumn based on the results if this study but further
             investigation is needed).
            A range of surface materials including concrete and recycled plastic could be
             suitable for use as initial settlement structures.
            Considering opportunities for multiple use benefits from the placement of
             structures – i.e. incorporating into seagrass friendly moorings the need for
             anchoring larger vessels in the main estuary to maximise return on investment.

Determining clear objectives for the placement of any artificial reef is essential to succuss of
the program (Brumbaugh et al. 2006). In this case the objectives may include:



Restoration of Noosa Estuary: An Assessment of Oyster Recruitment                               18