2019-01-14 General Committee Agenda - Attachment 2 to Item 2 - Aquatic Restoration and Management Options

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      Table 3 Expert evaluation of restoration and management options for Noosa Estuary. The predicted consequence for a range of indictors is illustrated with arrows. The direction of the arrow indicates
      either a predicted increase or decrease, and the relative size of the arrow provides a relative measure of the extent of the change likely as a result of each option (i.e., a larger arrow means a relatively
      larger expected impact for that indicator). Also presented for each option are associated ancillary benefits, key uncertainties, an estimate of cost, and potential risks to success of the option.

Option         Key actions              Consequence for chosen indicators                                                         Other benefits             Key uncertainties          Cost            Pre-mortem
                                                                                                                                                                                        estimate
                                        Prawns     Bream      Whiting     Mullet     Birds      Yabbies Crabs          Biodiver
                                                                                                                       sity
Restoration     Restore seagrass                                                                                                  Increased fisheries       Negative sentiment       $5k per          Community backlash and
of seagrass      habitat through                                                                                                    productivity               from community who       boat              lack of support
                 improved control                                                                                                  Increased availability     want “clean” sandy       mooring          Vessels anchoring rather
                 and redesign (e.g.,
                 swing moorings) of
                                                                                                        
                                                                                                                                    of habitat
                                                                                                                                   Carbon
                                                                                                                                                               beaches rather than
                                                                                                                                                               seagrass
                                                                                                                                                                                                          than using available
                                                                                                                                                                                                          seagrass friendly
                 boat moorings                                                         *#                                          sequestration                                                         moorings
                                                                                                                                   Improved
                                                                                                                                    management of
                                                                                                                                    boat mooring areas
Oyster reef     Create oyster reefs                                                                                               Improved water            Possible disease         $100K per        No community support
restoration      initially in Weyba                                                                                                 quality                    transmission             year              or community backlash
                 Creek and Lake                                                                                                    Sediment                  Natural recruitment      initially for    Increased oyster disease



                                                                                                          
                 Weyba                                                                                                              stabilisation              rates                    5 year            transmission

                                                                                                                                Citizen engagement
                                                                                                                                   Increased fishing
                                                                                                                                                              Survival of oysters
                                                                                                                                                              Design of reefs
                                                                                                                                                                                        pilot then
                                                                                                                                                                                        ongoing
                                                                                                                                                                                                         Increased E. coli
                                                                                                                                                                                                         No impact on the
                                                                                         *                                          aggregation               Future magnitude of                        receiving environment
                                                                                                                                   Enhancing existing         water quality                             Loss of other habitats
                                                                                                                                    mangrove and               improvements
                                                                                                                                    seagrass habitat
Living          Replace hardened                                                                                                  Increased public          Engineering viability    $1000+           Exacerbate erosion in
shorelines       shoreline protection                                                                                               awareness and             Public support through                     some areas
                 with structures that                                                                                               ownership                  shoreline stewardship                     Community backlash
                 incorporate                                                                                                       Erosion protection                                                   Inability to manage
                 mangroves and
                 oyster reefs
                                                                                                                    
                                                                                                                                   Improved natural
                                                                                                                                    aesthetics
                                                                                                                                                                                                          marine plants due to
                                                                                                                                                                                                          legislative implications
                Improve biological                                                      *                                         Atonement for past
                 connectivity and                                                                                                   actions
                 extent of habitat
                 mosaic between
                 Noosa and Tewantin
Provide         Sub-tidal reef                                                                                                    Oysters recruiting        Engineering              $100k+           Navigation hazards
habitat/hard     structures in the                                                                                                  naturally and              complexities /                            Fish attraction not
substrate
stepping
                 main channel
                 between Noosa and                                                                                  
                                                                                                                                    associated benefits
                                                                                                                                   Increased
                                                                                                                                                               modified
                                                                                                                                                               hydrodynamics
                                                                                                                                                                                                          production
                                                                                                                                                                                                         Invasion by exotic
stones           Tewantin                                                                *                                          recruitment of some       Meta-population                            species
                Improve biological                                                                                                 fisheries species          dynamics                                  Suffocate action
                 connectivity                                                                                                      Fish aggregation          Size and spacing of                       Reduction in soft


       – Positive effect on indicator species                            * shorebirds (e.g. migratory waders, oystercatchers etc.); # raptors; ^ seabirds; § consequence not able to be assessed due to a

       – Negative effect on indicator species                              lack of specificity about the actions to be taken