2019-01-14 General Committee Agenda - Attachment 2 to Item 2 - Aquatic Restoration and Management Options

to elicit risk information5. These additional pieces of assessment are also presented in Table
3.


Evaluation results
Based on the judgement of the experts involved in the workshop, the two options likely to
have the largest positive impact on the suite of indicators species are, oyster reef
restoration, and cessation of commercial prawn trawling (Table 3). Compared with the other
restoration activities considered, the recreation of oyster reefs within Noosa Estuary was
predicted to ultimately lead to relatively larger increases in important, structure using
recreational fish species (represent by bream in the indicator list), crab populations, and the
overall biodiversity of the estuary. The principal reasons why oyster reefs were considered
likely to have relatively larger impact than restoration of other habitats such as mangroves
and seagrass, is that that Noosa Estuary has retained a large amount of intact mangrove
habitat (Figure 4) such that it is unlikely to be a limiting feature in the system. Therefore
restoring additional mangrove habitat, while positive, is likely to only have a small impact on
the objectives considered here. Similarly for seagrass; there is a reasonable amount of
seagrass remaining in Noosa Estuary, and only a small number of places where additional
restoration would likely be successful.




Figure 4 Healthy mangrove habitat, Lake Cootharaba, Noosa.


5
 Game, E. T., J. A. Fitzsimons, G. Lipsett-Moore, and E. McDonald-Madden. 2013. Subjective risk assessment for planning conservation
projects. Environmental Research Letters 8:045027.



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