2015-10-13 Planning & Organisation Committee Agenda

PLANNING & ORGANISATION COMMITTEE MEETING AGENDA                            13 OCTOBER 2015


Overview of project findings
    Oysters recruited in moderate numbers at nearly all sites in the Noosa Estuary.
    The highest recruitment occurred in Weyba Creek, the main channel around Tewantin
      and between Goat Island and the Noosa North Shore.
    The growth rates of oysters recruiting on the tiles were reasonably fast.
    At least two major oyster recruitment events occurred in the intertidal habitats –
      between December 2014 to January 2015 and from March to April 2015.
    The greatest number of oysters recruiting to tiles in intertidal habitats occurred around
      March to April.
    Two to five times fewer oysters recruited to tiles deployed in sub-tidal habitats.
    Sediment was a major issue and prevented oyster recruitment of the upper surface
      and most vertical surfaces, such that settlement was restricted to the underside of the
      tiles.
    Two species of oysters dominated the recruitment, Planostrea pestigris and Pinctada
      maculate.
    Surprisingly to the researchers, no Sydney rock oysters (Saccostrea glomerata) were
      observed settling despite the widespread presence of adults in the estuary. Possible
      explanations for this include the presence of high sediment loads (i.e. runoff and re-
      suspension) or that oyster settlement of S. glomerata occurred at a different time of
      year.
    The oyster species that did recruit to the tiles during the assessment are not known to
      be reef building species. However these species still provide structural habitat and an
      important food source for commercially and recreationally important fisheries species.
    Numerous other species of marine life recruited to the settlement tiles including
      barnacles, mussels, bryozoans, ascidians, sponges and polychaete worms.
    These species contribute to food webs and provide a filtration function similar to that of
      commercial oyster species.
    There was also evidence of both crabs and fish utilising the newly created habitat
      associated with the settlement tiles and structures.
Full details are included in the oyster recruitment investigation report in Attachment 1.

Next Steps
Following the successful conclusion of the preliminary scoping study, it is understood that
the Thomas Foundation will be proposing:
(a)   to submit a grant application to the Noosa Biosphere Reserve Foundation to establish
      small scale oyster reef restoration trials at two or three sites in the Noosa Estuary; and
(b)   to seek Council’s in-kind technical support and advice on any environmental approvals
      that may be required from the State, as well as flood modelling advice and data which
      will assist in development of the grant proposal for the oyster reef trials.

Previous Council Consideration

Restoration of oyster reefs was one of a suite of restoration options evaluated by a team of
scientific expects as having the greatest potential to improve fish abundance and biodiversity
in Noosa Estuary.



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