2015-11-10 - P&O Agenda - Item 7, Attach 2 - Assessment of Oyster Recruitment

The enhancement of fisheries habitat through restoration of functional oyster reefs in
estuarine ecosystems has become a conservation priority in many locations (Brumbaugh et
al. 2006) (as a mechanism to improve the ecological function of estuaries through the
provision of increased habitat, improved water filtration and enhanced biodiversity,
particularly of recreational fish species), and was identified as a potential restoration activity
an expert workshop held in October 2015 in Brisbane by The Nature Conservancy. Natural
oyster reefs in estuaries globally have been in decline relative to historical records, due
primarily to overfishing (among other factors), and are considered functionally extinct in many
coastal estuaries, including along the East Coast of Australia (Beck et al. 2011).

Oysters have previously been a favourite food source for local indigenous populations in the
lower Noosa River Estuary, as evidenced by shell remains in midden mounds (Brown 2000).
Furthermore, according to historical accounts, Sydney rock oysters (Saccostrea glomerata)
grew extensively on rocks and other molluscs in the intertidal, and also in the shallow muddy
bottoms of the river channels and lakes at Noosa (Brown 2000). The Moreton Bay Oyster
Company dredged oysters from the Noosa River in the early 1900’s (Brown 2000). The
culture (seed oysters) was then sent to Moreton Bay for fattening, until environmental
changes from urbanisation and agricultural changes in the catchment destroyed the trade
(Brown 2000; Lergessner 2006).

Subtidal and intertidal reefs of Sydney rock oysters were also once extensive in nearby
Pumicestone Passage down to at least 4 m below the low tide mark (Lergessner 2006).
However, oyster reefs are now functionally extinct in Pumicestone Passage due largely to a
failure of oyster recruitment from declining water quality (Diggles 2013). Similarly, oyster
reefs are not currently a dominant ecosystem type within the Noosa estuary: suitability for
oystering has not been identified as a environmental value for any waters in the Noosa
Catchment under Schedule 1 of the EPP Water (DERM 2010).




Restoration of Noosa Estuary: An Assessment of Oyster Recruitment                                    2