2016-12-12 General Committee - Attachments 1, 2, 3 to Item 10 - Oyster Restoration Project

                                                             Ecological Service Professionals
                                                                                 Sustainable Science Solutions

aggregations of shell (a preferred settlement surface) at a suitable vertical height on the
shore (above LAT) and with sufficient vertical relief to mimic natural oyster reefs (i.e. >0.5 m).
The whole of Weyba Creek has conditions conducive to optimal growth of oysters in terms of
water temperature, salinity and depth (Table 3), however there are currently limited areas of
suitable structure particularly at an appropriate height above the sediment surface to allow
for oyster growth due to accumulation of fine sediment.
The negative impact of sedimentation on survival of oyster spat was highlighted in a recent
recruitment study (TNC & ESP 2015), which found that there was very limited recruitment to
the upper sides of settlement plates due to deposition of fine sediment and algae within just a
2 months of deployment. The current field assessment further highlighted the impact of the
accumulation of fine sediment on the available hard surfaces (Figure 19; Figure 20 & Figure
23). A plume of fine sediment on rocks was easily mobilised by creating a turbulent current
(sweeping hand motion) exposing dead oysters (Figure 20).




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