2019-01-14 General Committee Agenda - Attachment 3 to Item 2 - Monitoring of Noosa River Oyster Reefs Nov 2018

Monitoring criteria 4- Other potential effects
Performance objective
Oyster reef restoration units do not cause a decline in the extent of marine plants within a 50
m radius of the restoration units, and are not attributed to erosion of adjacent shorelines or
other ambient environmental impacts.

Monitoring method
Map the area of marine plant habitats (seagrass, mangroves) in the immediate vicinity (i.e.
with a 50 m buffer) of each oyster restoration area, using high-resolution GPS (cm scale)
and field-validated aerial imagery (sourced from Nearmap) (NearMap, 2018). Monitor
changes in the composition coverage and condition of seagrass within 50 m radius around
the oyster reefs. Map the location and condition of estuarine shorelines that occur in the
immediate vicinity (i.e. with a 50 m buffer) of each oyster reef, using high-resolution GPS
(cm scale) and field-validated aerial imagery (sourced from Nearmap).

Frequency
Annually for a minimum of three years, or until any failed restoration units have been
removed.

Was the performance objective met?
All aspects of this performance objective were met, so no further action is necessary.

Supporting evidence
Mangroves and seagrasses were successfully mapped at each site using the described
methods (Figures 8-21). We identified no significant change in the distribution of mangroves
or seagrasses within the 50 m monitoring area (Table 8; t test, P>0.9), or any erosion to
nearby shorelines. Whilst the footprint of seagrass was lower at some sites, there was no
loss of seagrass attributable to the installation of the reefs (i.e. significant decline of
seagrass away from the reefs, especially within the RAA areas). Photographs of the
mangrove fringe and shoreline within the 50 m monitoring area both before the installation,
and during the 12 month monitoring event are available from USC upon request.

Table 8 Extent of seagrass and length of mangrove edge at within 50m of each oyster
restoration site at installation and 12 months post installation.

        Mangroves at        Mangroves at 12      Seagrass at           Seagrass at 12
                                                                2                2
 Reef   installation (m)    months (m)           installation (m )     months (m )
 2      113.9               119.4                0                     0
 3      92.0                87.9                 1995.9                1443.6
 4      135.6               133.8                0                     0
 5      162.3               175.2                0                     0
 6      39.4                43.6                 1372.1                1590.0
 7      43.1                48.2                 1480.8                1913.5
 8      108.8               112.0                0                     0
 9      180.8               181.8                0                     0
 10     110.7               114.4                0                     0
 11     138.5               137.5                0                     0
 12     114.4               116.9                151.9                 499.0
 13     81.7                82.3                 2105.0                1707.5
 14     134.5               136.2                854.6                 765.5
 16     0                   0                    0                     0




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