2022-05-16 GC Agenda - Item 7 - Attachment 2 - Noosa Oyster Ecosystem Restoration Project - Project Restoration Plan

                 Figure 1.2: Lake Weyba Oyster Collecting circa 1914. Source: Sunshinecoast.spydus.com



                 Of note is the that due to the conversion of Hays Island into the Noosa Sound canal estate in the 1960s,
                 evidence of oyster beds from this area has been lost. Oysters persist though on rocks, gravel and pylons
                 along the southern fringes of Noosa Sound, indicating that oyster spat still settle and grow in the area.
                 The potential for restoration of oysters in the Noosa Sound therefore remains possible (TNC shellfish
                 ecologist, Boze Hancock, pers com).

                 In 2016, Ecological Service Professionals (ESP) quantified the historic spatial extent of oyster beds in the
                 Noosa River and concluded that it was likely to have been in the range of 41,530m2 to 207,650 m2, of
                 which approximately 16,850m2 of old oyster beds and oyster rubble remain buried by sediment in the
                 historical oyster lease areas2.

                 The loss of oyster biomass likely resulted in the ecosystem collapsing, with shellfish ecosystems now
                 replaced primarily by soft (sandy and muddy) sediments. Changes to the estuary’s physical-chemical
                 condition, canal development and shoreline armouring have also likely contributed to the decline of
                 the ecosystem or inhibited its natural recovery.

                 Today, no extant rock oyster ecosystems exist in the Noosa River estuary, despite the presence of
                 individual and small populations of rock oysters. The closest known intact oyster-dominated shellfish
                 ecosystem is found near North Stradbroke Island in Morton Bay. Notably, a recent study3 identified that
                 rock oyster dominated shellfish ecosystems are the most threatened marine ecosystem in Australia,
                 with up to 94 percent of the ecosystem lost throughout Australia since European settlement.




                 2
                   Walker, S. 2016. Assessment of Oyster Habitat in Noosa River Estuary. Report to Noosa Shire Council by Ecological Service Professionals
                 (ESP). October 2016.

                 3
                   Gillies et al. 2018. Australian Shellfish Ecosystems: past distribution, current status and future management. PLoS ONE 13(2):e0190914.
                 https://doi.org/10.1371/journal.pone.0190914

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Document Set ID: 21802641
Version: 1, Version Date: 31/01/2022