2022-11-08 Planning & Environment Meeting Agenda

PLANNING & ENVIRONMENT COMMITTEE MEETING AGENDA   8 NOVEMBER 2022




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PLANNING & ENVIRONMENT COMMITTEE MEETING AGENDA                                                          8 NOVEMBER 2022

                                                                                           TheNature (%&
                                                                                           Conservancy \
                                                                                                        Australia

         Seagrass as habitat                                           Why seagrass changes
         Seagrass meadows provide food and shelter for a diverse       Seagrasses are highly sensitive to changes in
         range of marine fauna. They also support benthic              environmental conditions and declines in water quality
         macroinvertebrate communities, which in turn provide          (particularly high levels of suspended sediment in the
         food for many larger, commercially and recreationally         water) and are therefore considered indicators of
         important species of crustacean, mollusc and finfish.         environmental stress or degradation.
                                                                       As a result, the spatial distribution of seagrass can be
         Current seagrass extent                                       highly dynamic, with large interannual changes in the
                     .          .     .               .                extent of seagrass habitats and community structure
         Lie Nooss River eral s comin       by sok sec dfs ° ry        resulting from natural disturbances, These natural
         with aevensl seneast veod u“ ' wri     ‘nth -    : 5,         disturbances however, do not typically result in a net loss
                        grass  meadows occurring in the lowe           of seagrass coverage over time,
         estuary.                                                                                      ,
         The seagrass meadows are dominated by Long Eelgrass           What is next for Noosa’s seagrass
         (Zostera muelleri sub sp,capricomi) with occasional sparse    Becaue of their importance for estuarine ecosystems, the
         patches of Halophila ovalis. Z, muelleri meadow are           precise drivers for the decline and lack of recovery of the
         predominantly found in dense, but patchy, beds along the      Noosa River Estuary seagrass meadows need urgent
         main channel and around several small islands,                investigation, Better understanding of the Noosa River
                                                                       system would advise river managers, who could advocate
         Seagr ass decline                                             for resources to enable research and recovery action,
         Since 1989, the Noosa River estuary has lost 80 percent of
         iits seagrass and is showing no signs of recovery (see Table  Final comment from the expert
         1). In 1989, seagrass covered 337.4 hectares of Noosa         “Recovery from impacts such as flooding in other similar
         estuary, By 2006, this coverage had fallen to just 53,7 ha.   seagrass meadows has occurred within a few years. This is
         The largest seagrass declines have been in the main           not the case in Noosa, ”
         channel, Lake Weyba and Lake Cooroibah,                       Simon Walker (Director and Principal Ecologist -
         Studies in 2009 and 2020 confirmed that despite some          EcologicalService Professionals)
         minor seasonal fluctuations, Noosa’s seagrass meadows
         have not recovered, In other parts of Queensland,            Full report
         including the southeast, Zostera-dominated seagrass           Walker SJ, Hayes M, Watson €, Goodwin S & Thorburn L.
         meadows typically recover quickly from significant losses,    2021, Current and historical distribution of seagrass in the
         often within a few years, The lack of seagrass recovery in    Noosa   Estuary, Report  prepared   for  The   Nature
          Noosa is therefore alarming,                                 Conservancy, September 2021. 37pp.
         What caused the seagrass loss
         Storms and flooding most likely caused the major loss of
         seagrass in the Noosa River estuary. The big question
         today is: What is preventing the recovery of the
         Noosa River estuary’s seagrass meadows?

           Table 1, Results of the Seagrass mapping comparison from 1987 to 2020.
            Reach                        Area (m?) of Seagrass                              Oe Tre be     Bo)
                                            cL ad      FEES)     2006      2009      2020   2020 (%)
            Lake Cooroibah                   NA     229,624    71,323    61,672         0               -100
            Noosa River — Tewantin       106,651    134.541    39,360    36,731    28,540                79
            Noosa River — Goat Island    93,865     105.247    28831     23,539     9,313                01
                 ba Creek                    NA     647.065   270,366   239,551   205,510                68
                                (my          NA   3,374,086   537,038   725,258   561,512                -83
           Total            Area
            Total Seagrass Area (Ha)
            Noosa Estuary                   NA        337.4      53.7      725       564                -83

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