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

                                                                                    and further distorts any potential
                                                                                    natural character of the substrate.

                                                                                    Placing shell in cages, which
                                                                                    decompose by rusting over time, may
                                                                                    allow time for oyster shells to cement
                                                                                    together by natural biogenic
                                                                                    processes, prior to the supporting
                                                                                    cage structure disappearing. However,
                                                                                    this design is yet to be fully tested and
                                                                                    is possibly best suited for sub-tidal
                                                                                    environments where the biogenic
                                                                                    structures are not subject to high
                                                                                    current and wave energy, which may
                                                                                    cause movement or erosion of the
                                                                                    biogenic reef structures.

                                                                                    Not augmenting the restoration
                                                                                    substrate with oyster shell and seeded
                                                                                    oyster cultch and live oysters risks
                                                                                    slow ecological recovery, or possibly
                                                                                    low recruitment due to the variable
                                                                                    nature of oyster recruitment.
                  Substrate            Substrates are designed to maximise          Alternative configurations could
                  design               stability, durability, rugosity,             include larger substrate footprints of
                  engineering          heterogeneity, prevent impediment to         continuous rock, but such structures
                                       fish passage, avoid pooling, minimise        would likely affect river flow, may
                                       wave refraction, and erosion of              create barriers to fish passage,
                                       shorelines.                                  enhance the erosion potential and
                                                                                    sediment accretion potential of the
                                                                                    substrates to the adjacent shoreline
                                                                                    and shoreline upstream and
                                                                                    downstream of the restoration site.

                  Works                The construction contractor will be          The work methods are standard
                  methods              responsible for all works, from material     practice which are refined for each
                                       storage and load out to construction,        estuary situation. Work methods are
                                       construction monitoring, risk                adaptively refined, if required, but the
                                       management and reporting.                    conservation of existing habitats is
                                                                                    paramount to the methods.
                                       The contractor will operate in accordance
                                       with the specifications in this plan, Site   The use of larger deployment
                                       Establishment and Management Plan and        equipment, deployment of smaller
                                       Construction and Environmental               amounts of substrate but this is
                                       Management Plan (CEMP) and all relevant      neither economically efficient nor
                                       permit conditions.                           enables the project to meet minimum
                                                                                    restoration targets in an effective
                                       Substrate deployment is timed to coincide    timeframe.
                                       with periods of the highest natural oyster


                                                                                                                           55




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