Annex 1 - Noosa River Habitat Survey Report - ESP

                                                                   Ecological Service Professionals
                                                                                     Sustainable Science Solutions




   Figure 3.10 Narrow area of rock rubble with rock oysters adjacent to council chambers with narrow
               band of grey mangroves further landward




   Figure 3.11 Intertidal rock rubble and gravel adjacent to the existing boat ramp and jetty

In subtidal areas, exposed rock surfaces had a high coverage of fine algal turf that trapped a
thick sediment layer. Macroalgae growing on rocks was dominated by Padina sp.,
particularly in shallow subtidal areas along the edge of the existing navigation channel and
around the existing channel marker (Figure 3.12). These species were generally restricted to
subtidal areas and cover was typically sparse (less than 15% of the surface area),
particularly in rocky areas close to the shoreline (Figure 3.12). There was a small section of
more substantial rocky reef with high vertical relief around the existing channel marker sign,
where the densest aggregation of macroalgae (<30% cover) occurred (Figure 3.14). There
was also denser macroalgae growing on rubble at the edge of the main river channel and
also south of the existing boat ramp adjacent to the bathing area and marina (Figure 3.15).
The macroalgal assemblages were in relatively poor condition due to high sediment loads
observed on and around the existing rocky reef and rubble areas, with some sections of reef
having a high coverage of fine sediment (Figure 3.16).
Given the speed at which Padina can colonise hard surfaces (dead oyster shell) elsewhere in
the estuary (ESP 2021), it is anticipated that supplementary habitat provided as part of the
proposed restoration project would be colonised rapidly within 1 year of deployment, and that
coverage would be similar to the current condition within 2 to 3 years post deployment,
particularly in sections that remain subtidal and not covered by fine silt.




Noosa Oyster Reef Restoration: Marine Benthic Habitat Assessment                                              16