2022-04-12 Planning & Environment Meeting Agenda

PLANNING & ENVIRONMENT COMMITTEE MEETING AGENDA    12 APRIL 2022


                                                  ATTACHMENT 6




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PLANNING & ENVIRONMENT COMMITTEE MEETING AGENDA                                              12 APRIL 2022

                                                                                           ATTACHMENT 6

     Date:     23 February 2022
     To:       Shaun Walsh — Noosa Council
     Ce:       Larry Sengstock, Kim Rawlings, Leo Jensen — Noosa Council
     From:     Dr Eddie Game - The Nature Conservancy
     Subject:  Response to questions to Noosa Council regarding QX and winter mortality disease risk
               to Sydney Rock Oyster ecosystem restoration in the Noosa River estuary.

    Thank you for the opportunity to respond to this inquiry. TNC is a science-based organization which
    takes environmental disease, biosecurity and other risks to project success very seriously. We
    therefore carefully evaluate and manage for these risks in restoration projects like the Noosa Oyster
    Ecosystem Restoration Project.
    Below is a summary of the key points in our response, followed by a more detailed explanation.

    @   QXand winter mortality disease are endemic to South-east Queensland and occur where rock
        oysters are found.

    e@  These diseases can cause high, but rarely total, mortality in rock oyster populations. Mortality
        rates are highly variable.

    @   Wild populations of oysters have some natural resilience to endemic disease.

    e@ = The larger and more genetically diverse an oyster population is, the greater its chances of
        developing natural resilience to disease.

    @   TNC has taken a careful and precautionary approach to ameliorate the impact of environmental
        risks such as QX and winter mortality disease to Noosa’s oyster restoration efforts.
        Supplementing natural recruitment with hatchery-reared Noosa oysters placed on the reefs will
        help combat oyster mortality due to disease and also other environmental factors.

    @   TNC will monitor the reefs closely and continue to rely on its extensive local and international
        network of shellfish experts to inform management responses and address threats to oyster
        restoration.

    @   Restoration is an action to boost the number, genetic diversity and thus resilience of rock
        oysters and associated species and is a key reason why human assisted oyster ecosystem
        restoration is required.

    About QX disease and winter mortality in Sydney rock oysters
    “QX' stands for ‘Queensland Unknown’, the title given to this disease before scientists discovered the
    parasitic organism that we now know causes it. In 1976, Marteilia sydneyi was formally described as
    the cause of OX disease in oysters. Marteilia sydneyi is a protozoan (single-celled) parasite that
    belongs to a small group of parasites that mostly affect bivalves (animals with two ‘shells’, such as

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