Appendix 3- Noosa restoration assessment report- Including Expert Elicitation Minutes

In contrast, Noosa Estuary has very little hard substrate such as biogenic reefs. Reefs formed
from oysters appear likely to have been a historical component of Noosa Estuary6,7,8 but are
now almost entirely missing. As such, restoring oyster reef habitat is likely to make an
important contribution to restoring the ecology of Noosa Estuary and particularly its
fisheries productivity. Other notable benefits of oyster reef restoration would likely include
improved water quality because of the filtration conducted by oysters 9, enhanced
productivity of existing mangroves and seagrass species as the connection between habitats
is important for many species, additional recreational fishing areas as many fish are likely to
be attracted to oyster reefs for feeding, and numerous citizen engagement opportunities in
their development and subsequent monitoring.
Oyster reef restoration would likely focus on Saccostrea glomerata (Sydney rock oyster, see
Figure 2) as this is the most abundant native oyster in Noosa Estuary. There is also the
possibility that reefs could be developed using may be multi-species including others that
are found in Noosa Estuary such as Isognomon ephippium (Rounded Tooth pearl oyster, see
Figure 3). Because the reconstruction of Saccostrea glomerata reefs has not previously been
undertaken, there are uncertainties around the design of the restored reefs (e.g., what
engineered structures to use), and the magnitude of the benefits that could be expected.
Similarly, although oysters are naturally present in the Noosa Estuary, it is uncertain
whether recruitment and survival of oysters is adequate to re-establish reefs without
hatchery raised spat. Another risk is that the establishment of large number of oysters in the
estuary could lead to increased incidence of oyster disease that may harm the existing
oyster populations in the estuary.
With regard to managing existing activities within Noosa Estuary, the option likely to deliver
the greatest benefit towards the objectives identified here was the cessation of commercial
prawn trawling. The principal reasons for this predicted impact are that the school prawns
targeted by the commercial fishery are a critical part of the Noosa Estuary aquatic
ecosystem (as identified in Table 1), and their current abundance is likely to be much
reduced from historical levels. Additionally, the use of beam-trawls to capture the prawns is
likely to do major damage to benthic habitats, such that cessation of trawling will deliver a
range of fisheries related benefits through both the increased abundance of prawns and the
increased integrity of benthic habitats in the estuary. Because any future management of
the prawn fishery is unlikely to involve either TTF or TNC, we have considered it further in
our recommendations.
For the options that involved restoration of the Kin Kin catchment and storm water
management, the experts involved did not feel able to evaluate the likely consequences
because the current level of impact each of these has on the Noosa Estuary aquatic
environment was not clearly known.



6
  Beck, M., D. R. Brumbaugh, L. Airoldi, A. Carranza, L. D. Coen, C. Crawford, O. Defeo, G. J. Edgar, B. Hancock, M. C. Kay, H. S. Lenihan, M.
W. Luckenback, C. L. Toropova, G. Zhang, and X. Guo. 2011. Oyster reefs at risk and recommendations for conservation, restoration, and
management. Bioscience 61:107-11
7
   Brown, E. R. 2000. Cooloola Coast: Noosa to Fraser Island: The Aboriginal and Settlers Histories of a Unique Environment. Univ. of
Queensland Press.
8
  Lergessner, J. G. 2006. Oysterers of Moreton Bay. James Lergessner.
9
   Zu Ermgassen, P. S., M. D. Spalding, R. E. Grizzle, and R. D. Brumbaugh. 2013. Quantifying the loss of a marine ecosystem service:
filtration by the eastern oyster in US estuaries. Estuaries and coasts 36:36-43.



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