Enclosure 6 - ESP Letter

                                                                              Ecological Service Professionals
                                                                                                        Sustainable Science Solutions

to a current Resource Allocation Authority and Development Application to restore lost oyster
reef habitat through the QLD Government). The aim of this restoration project is to restore
the complexity of habitat in the estuarine seascape.



Assessment Method
1. A desktop study was completed to describe the historical status of oyster reefs in the
Noosa River Estuary, to provide a context for the field survey results and identify areas that
may be suitable for oyster growth. This mostly relied on the existing work compiled by Ruth
Thurstan, supplemented by other available reports / data where available. The desktop
assessment informed suitable locations to be visited in the field survey to confirm the
presence of oyster beds or reefs.
2. A field survey was completed on the 25th and 26th of October 2016 by Dr Simon Walker
(ESP) and Bryan Walsh (NPA), to provide a preliminary assessment and map of the extent of
oyster reef, bed and aggregation habitat in the lower estuary. Our assessment of the
substrate type was made at several locations within the estuary (largely focussed on areas
known to have hard substrate or sites proposed in Council’s Resource Allocation Authority).
Visual assessments were completed either from a boat, on foot or snorkel (in areas of poor
visibility) using an underwater video camera. The presence of dead shell or living oysters,
hard substrate or marine plants (primarily seagrass and macroalgae) were extent was
recorded using GPS. The extent of seagrass was interpolated from satellite imagery of the
area and field validated using a series of spot checks with a boat deployed camera or on
snorkel. The full extent of seagrass in the estuary was not mapped. The following habitat
categories were used in our assessment:
    Table 1       Habitat category descriptions

Habitat     Brief Habitat Description
Category




Shell bed   Aggregation of dead shell (conch) on the surface of sediment, including a dead shell from variety of species such
            as oysters, clams and snails.

Oyster      A dense aggregation of leaf oysters in low relief (<0.5 m) growing on soft sediment surface and providing
Bed         substrate for rock oysters and other sessile organisms to survive (Beck et al. 2009).

Oyster      A dense aggregation of oysters growing on dead oyster shell on soft sediment with high vertical relief (>0.5 m)
Reef        above sediment surface (Beck et al. 2009).

Rubble      Predominantly rocky rubble, gravel, pebbles and boulders protruding from the sediment surface, with oysters
Bank        aggregating on the surface or dead shell surrounding rock.

Rocky       Predominantly hard rock shelf protruding from the sediment surface, with oysters aggregating on the surface of
Reef        rocks.

Coffee      Predominantly coffee rock shelf protruding from the sediment surface, with sparse oysters growing on surface.
Rock Reef

Seagrass    Seagrass beds varied from 5 to >90% coverage, including Zostera mulleri, Halophila ovalis and Halodule spp..
beds



The extent of habitat was identified visually and mapped with a hand held GPS. A map
showing the areas searched is provided in Appendix A.



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