Biodiversity Strategy - Gosford City Council - NSW Government

Brisbane Water lies immediately adjacent to Gosford City’s central business district and many of
its suburbs. Urban areas have developed around the foreshore with the major concentrations
being centered in Gosford to the north and Woy Woy / Umina to the south west. The eastern
shore of the Estuary is also relatively heavily developed. The waterway is shallow and supports
a large oyster growing industry. Recreational boat usage is high and commercial vessels run
commuter and tourist services throughout the waterway. The high energy environment and
mobile sand shoals of the lower Estuary leads to the need to assess navigation issues
frequently.
Major tributaries of Brisbane Water include Woy Woy Creek, Corrumbine Creek, Narara Creek,
Erina Creek, Egan Creek, Kincumber Creek. Various other minor tributaries flow into the
Estuary. Kincumber Creek is the tributary of greatest concern with generally high levels of faecal
contamination and nutrients. Erina Creek also has high nutrient loads and development within
both these catchments will continue to put pressure on downstream ecosystems. Narara Creek
catchment contains most of Gosford's industrial estates and the creek has been polluted over
the years with a variety of toxic chemicals and heavy metals. Many of these toxicants are
persistent in the marine environment, accumulating in sediments and entering food chains.
Brisbane Water is listed in the Directory of Important Wetlands with approximately 23% and
25% of the total area of the saltmarshes and mangroves, respectively, is included in national
parks and nature reserves. Riley’s Island and Pelican Island nature reserves provide critical
feeding and breeding areas for a range of migratory wader species, twelve of which are listed in
JAMBA or CAMBA. The site is also important for the Bush Stone-curlew (Burhinus grallarius),
Pied Oystercatcher (Haematopus longirostris), Eastern Curlew (Numenius madagascariensis)
and a Pelican rookery. Brisbane Water has been identified as a second priority candidate site
(after Lake Macquarie) for an estuarine aquatic reserve within the Hawkesbury Shelf Marine
Bioregion (Breen et al. 2005). The estuary includes a rare combination of fish species and it
remains the only barrier estuary in the bioregion with an entrance not kept open by artificial
breakwalls.
Management of the estuary is guided by the Brisbane Water Plan of Management (GCC, 1995).
This document specifies appropriate controls and guidelines for regulating development in the
area as well as policy to control building activity and structures on and around Brisbane Water
and its standards also apply to building applications. However, the Management Plan is
relatively outdated and various new legislative controls need to be considered. Further,
understanding of estuarine processes and their interconnectivity with estuarine ecology has
advanced considerably since 1995.
Council is currently reviewing the Brisbane Water Plan of Management under the State's
Estuary Management Program. The new Brisbane Water Estuary Management Plan will replace
the old as the guiding document for management and conservation of biodiversity in the
estuary.
A major component of this work is the development of the Brisbane Water Estuary Processes
Study, which is due for completion in December 2006. Understanding complex interactions
between natural and anthropogenic processes is important to managing the natural resource
basis of the waterway. Therefore, a major component of the Study is the integration of
catchment land-use, hydrylogic/hydrdynamic modelling and ecological phenomena. For
example, modelling is being used to assess larval transport and link survival and settlement of
marine organisms to both natural and anthropogenic (man-made) processes within the
catchment, the estuary and the larger marine environment.
The Brisbane Water Estuary Processes study is linked to a number of other projects designed
to investigate and describe the ecology of the estuary. A major study is the Brisbane Water
Biodiversity Study, which will map patterns of distribution and abundance of marine fauna and
flora into Council's geographic information system (GIS). This project is nearing completion.
Biodiversity - Technical Report Page 141