AusGeo News  March 2007  Issue No. 85

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New information on Australia’s Near-Pristine Estuaries

Fig 1. Australia’s near-pristine estuaries according to geomorphic type.

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.

Figure 1. Australia’s near-pristine estuaries according to geomorphic type and in relation to IMCRA bioregions (IMCRA 1998). Estuary classification from National Land and Water Resources Audit 2002. (Larger image [GIF 294.7kb])

Australia’s near-pristine estuaries are some of our most valuable natural assets. They are important for:

Fig 2. Detailed map of near-pristine estuaries of Tasmania.

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.

Figure 2. Detailed map of IMCRA regions and near-pristine estuaries of Tasmania. (Larger image [GIF 364.5kb])

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 emma.murray@ga.gov.au)

Related websites

Near-Pristine Estuaries Project page

Several reports on Australia’s near-pristine estuaries are also available on the Coastal CRC website. These include:

References

  1. Heap A, Bryce S, Ryan D, Radke L, Smith C, Harris P & Heggie D. 2001. Australian Estuaries and Coastal Waterways: A geoscience perspective for improved and integrated resource management. A report to the National Land and Water Resources Audit, Theme 7: Ecosystem Health. Australian Geological Survey Organisation Record. 2001/07. http://dbforms.ga.gov.au/pls/www/npm.ozest.pubs_reports
  2. IMCRA. 1998. Interim Marine and Coastal Regionalisation for Australia: an ecosystem-based classification for marine and coastal environments. Version 3.3. Interim Marine and Coastal Regionalisation for Australia Technical Group, Environment Australia, Canberra. www.deh.gov.au/coasts/mpa/nrsmpa/pubs/imcra.pdf
  3. NLWRA. 2002. Australian Catchment, River and Estuary Assessment 2002, volume 1. National Land and Water Resources Audit, Commonwealth Government, Canberra. http://audit.ea.gov.au/anra/coasts/coasts_frame.cfm?region_type=AUS&region_code=AUS&info=estuaries Data also available at www.ozestuaries.org
  4. Ryan DA, Heap AD, Radke L & Heggie DT. 2003. Conceptual models of Australia’s estuaries and coastal waterways: applications for coastal resource management. Geoscience Australia Record. 2003/09. Geoscience Australia, Canberra. www.ozestuaries.org/conceptual_mods/conceptual.jsp

New geophysical datasets released

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
Map Sheets		 Line Spacing (m),
terrain clearance (m),
orientation		 Line Km Contractor
Bowen – Surat North (Qld) Magnetic, Radiometric, Elevation Jan – July 2006
Springsure, Baralaba, Monto, Eddystone, Taroom, Mundubbera, Mitchell, Roma, Chinchilla		 400,
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
96 000		 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
and Camooweal
(eastern half);
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 murray.richardson@ga.gov.au)

Related websites

NT Geological Survey

Geological Survey of WA

Geological Survey of Qld

Geological Survey of NSW

Price drop for Synthetic Aperture Radar (SAR) satellite imagery

Fig 1. Earth Resources Satellite SAR image over Whitsunday Islands, Queensland.

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.

Figure 1. Earth Resources Satellite SAR image over Whitsunday Islands, Queensland © European Space Agency. (Larger image [JPG 408.4kb])

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

Related websites

European Space Agency (ESA)

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