AusGeo News March 2007 Issue No. 85
Around half of Australia’s estuaries (that is, 470 out of 974) were classified as ‘near-pristine’ during the National Land and Water Resources Audit (NLWRA) conducted in 2001 (NLWRA 2002). The NLWRA definition of a near-pristine estuary includes those estuaries with greater than 90 per cent natural vegetation cover in a catchment which has no dams, alterations to tidal flow or aquaculture, and minimal fishing.
Australia’s near-pristine estuaries are some of our most valuable natural assets. They are important for:
Many countries have only a few or no remaining near-pristine estuaries and therefore lack opportunities for significant biodiversity conservation and scientific research.
Australia’s near-pristine estuaries are located away from major population centres in the most remote and inaccessible parts of the coastline, such as across northern Australia and southwest Tasmania. They also differ according to the region, for example, estuaries in northern Australia are shaped mainly by tides, whereas in southern Australia they are shaped mainly by waves (Ryan et al 2003). Most near-pristine estuaries in Australia (approximately 65 per cent) fall into tide-dominated classifications.
Geoscience Australia, in collaboration with CSIRO Land and Water and the Coastal CRC, has recently released online resources and information about Australia’s near-pristine estuaries through the OzEstuaries and Coastal CRC websites.
The Near-Pristine Estuaries Project page in OzEstuaries includes a map showing the location and geomorphic type of Australia’s near-pristine estuaries (figure 1) in relation to coastal IMCRA bioregions (Interim Marine and Coastal Regionalisation for Australia; IMCRA 1998). Visitors can also zoom in on specific regions to load more detailed maps (figure 2). The webpage also includes an interactive map that can summarise typical pristine characteristics of estuaries by region around the Australian coastline. In showing the estuaries against a backdrop of IMCRA bioregions, these maps can be used to help plan a system of representative marine protected areas.
For more information phone Emma Murray on +61 2 6249 9019 (email firstname.lastname@example.org)
Several reports on Australia’s near-pristine estuaries are also available on the Coastal CRC website. These include:
Datasets from nine new geophysical surveys, released since August 2006, will be a valuable tool in assessing the mineral potential of the respective survey areas.
They include seven airborne magnetic and radiometric surveys in the Bowen-Surat and Mt Isa regions in Queensland, the Tiwi Islands in the Northern Territory, the Musgrave Extensions in Western Australia as well as the Eromanga-Thomson area and the Southern Darling and Murray Basins in New South Wales. The new gravity surveys include the Webb region in Western Australia and part of the Mt Isa region in Queensland.
The data were acquired in surveys conducted in 2005 and 2006 and, except those in New South Wales, were managed by Geoscience Australia on behalf of the Geological Surveys of Queensland, Western Australia and the Northern Territory. The three surveys in New South Wales were acquired in 2005 and managed by the Geological Survey of NSW.
The datasets have been incorporated into the national geophysical databases. The point-located and gridded data for the nine surveys can be obtained free online using the GADDS download facility.
Table 1. Details of the airborne surveys.
|Survey||Survey Type||Date of Acquisition||1:250 000
|Line Spacing (m),
terrain clearance (m),
|Bowen – Surat North (Qld)||Magnetic, Radiometric, Elevation||Jan – July 2006||
Springsure, Baralaba, Monto, Eddystone, Taroom, Mundubbera, Mitchell, Roma, Chinchilla
80, east – west
|169 882||UTS Geophysics|
Mount Isa South – West (Qld)
|Magnetic, Radiometric, Elevation||April – Aug 2006||Mount Whelan, Bedourie, Machattie, Birdsville, Betoota||400,
80, east – west
|140 500||Fugro Airborne Surveys|
|Tiwi Islands (NT)||Magnetic, Radiometric, Elevation||Oct – Nov 2006||Bathurst Island, Melville Island, Darwin||400,
80, north – south
|29 874||Fugro Airborne Surveys|
|Musgrave Extensions (WA)||
Magnetic, Radiometric, Elevation
|June – Oct 2006||Musgrave North: Bentley, Scott, Cobb; Musgrave South: Talbot, Cooper||Musgrave North: 400,
60, north – south
Musgrave South: 400, 60, east – west
|82 094||Fugro Airborne Surveys|
|Southern Darling Basin (NSW)||Magnetic, Radiometric, Elevation||March – June 2005||Manara, Ivanhoe||400,
60, north – south
|18 000||Fugro Airborne Surveys|
|Murray Basin (NSW)||Magnetic, Radiometric, Elevation||April – Aug 2005||Menindee, Anabranch, Pooncarie Mildura, Balranald||400,
60, east – west
|Fugro Airborne Surveys|
|Eromanga-Thomson (NSW)||Magnetic, Radiometric, Elevation||Aug – Dec 2005||Urisino, White Cliffs, Yantabulla, Louth||250 & 400, 60, east – west or north - south||166 000||
Fugro Airborne Surveys
Table 2. Details of the gravity surveys.
|Survey (State)||Survey Type||Date of Acquisition||1:250 000 Map Sheets||Station Spacing/ orientation||Stations||Contractor|
|Webb (WA)||Gravity||Aug – Sept 2006||Webb, Wilson, Ryan, Macdonald||2.5 x 2.5 km
east - west
|4 103||Daishsat Geodetic Surveyors|
|Mount Isa Area B (Qld)||Gravity||Sept – Oct 2006||Lawn Hill, Donors Hill, Camooweal, Dobbyn, Mt Isa (western half)|| 2.0 x 2.0 km east – west on Dobbyn
4.0 x 4.0 km east – west (remainder)
|9 857||Fugro Ground Geophysics|
For more information phone Murray Richardson on +61 2 6249 9229 (email email@example.com)
Geoscience Australia is pleased to announce a major price reduction in Synthetic Aperture Radar (SAR) products downloaded from the Earth Resource Satellite (ERS). Prices have fallen from over $2000 to $590 as a result of greater pricing flexibility by the satellite operator. The reduced price will increase the attractiveness and utilisation of the SAR data produced by ERS to a wide range of users. In addition, and for a small fee, customers may also place requests for the ERS satellite to acquire data over a particular area in the future.
SAR products have been available from Geoscience Australia’s remote sensing unit (ACRES) since 1993. A major advantage of SAR data is its ability to image the Earth through cloud or at night. C-band SAR data is particularly useful in coastal and ocean environments where it has been successfully used in helping to identify oil seeps and slicks, and ship detection.
Geoscience Australia holds a large and comprehensive archive of SAR data covering Australia and New Zealand, including complete continental coverages from the ERS-1 and ERS-2 tandem mission undertaken over nine months in 1995–96. During the tandem mission the orbit configuration enabled global observations, one day apart, from the two satellites. This data is particularly suited for interferometric applications, including subsidence monitoring and Digital Elevation Model (DEM) generation. The ERS-1 and ERS-2 SAR data may also be used for time-series studies with the currently available Envisat ASAR data.
For more information vist www.ga.gov.au/acres/prod_ser/ersdata.jsp