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geoscientificInformation

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  • The principle aim of this project was to map the fine-scale spatial distribution of key abalone habitat impacted by urchins in < 25 m water depth using multibeam acoustic imagery. Detailed substrate type (Pavement Reef, Megaclast Reef, Mixed Consolidated Sediment/Reef and Sand), and kelp coverage maps have been produced for the east coast of Tasmania. Large urchin barrens have been predicted and the minimum quantifiable unit of which small incipient barrens can be detected has been identified using this acoustic water column technique. This data provides a snapshot of the 2021 distribution of seafloor habitats and associated vegetation distribution, and will assist in the facilitation of strategic decision making for urchin control and abalone management. Data for download has been split by fishing block (22-24, 27-30). This record describes *FISHING BLOCK 23*. The following data products are available for download, for each fishing block: • 50cm resolution bathymetry • 50cm resolution substrate type (Seamap Australia classification) • bathymetry derivatives (seabed slope, curvature, rugosity, 1 and 2m contours) • water column data - 1m mean signal • water column data - 9m2 raw block statistic • water column data - vegetation likelihood classification See associated records for access to data from other fishing blocks (22, 24, 27, 28, 29, 30).

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    The Petrel Sub-basin Marine Environmental Survey GA-0335, (SOL5463) was undertaken by the RV Solander during May 2012 as part of the Commonwealth Government's National Low Emission Coal Initiative (NLECI). The survey was undertaken as a collaboration between the Australian Institute of Marine Science (AIMS) and GA. The purpose was to acquire geophysical and biophysical data on shallow (less then 100m water depth) seabed environments within two targeted areas in the Petrel Sub-basin to support investigation for CO2 storage potential in these areas. This dataset comprises an interpreted geomorphic map. Interpreted local-scale geomorphic maps were produced for each survey area in the Petrel Sub-basin using multibeam bathymetry and backscatter grids at 2 m resolution and bathymetric derivatives (e.g. slope; 1-m contours). Five geomorphic units; bank, plain, ridge, terrace and valley, were identified and mapped using definitions suitable for interpretation at the local scale (nominally 1:10 000). Maps and polygons were manual digitised in ArcGIS using the spatial analyst and 3D analyst toolboxes.

  • Raised features were derived by aggregating and dissolving the boundaries of the 1 degree S57 file series for the Australian continental shelf and Lord Howe Island shelf (200 m) depicting depth area features. An algorithm was applied to the data that isolated these features from surrounding lower features or plains.

  • Depth areas were derived by aggregating and dissolving the boundaries of the 1 degree S57 file series for the Australian continental shelf and Lord Howe Island shelf (200 m) depicting depth area polygons.

  • The intertidal area was derived by aggregating and dissolving the boundaries of the 1 degree S57 file series for the Australian continental shelf and Lord Howe Island shelf (200 m) depicting depth area features.

  • Voyage IN2019_V04 contributed an additional 29,000 kms2 of seafloor survey data to the Coral Sea knowledge base. From this new bathymetric data individual seamounts have been extracted and have been classified to the Geoscience Australia Geomorphology Classification Scheme. This dataset contains two layers representing the classification layers- 1) Surface (Plain, Slope, Escarpment) and 2) fine scale Geomorphology of the seamount for the Cassowary Seamount. Ongoing research with this survey data will provide new insights into the detailed geomorphic shape and spatial relationships between adjacent seabed features. This information will be released in future publications to show the potential of how the scale of such seafloor data can be used for predictive habitat modelling when analysed with the biological data overlays.

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    This dataset comprises derived bathymetric isobaths (depth contour lines) generated from the Geoscience Australia (GA) AusBathyTopo 250m 2024 gridded bathymetric dataset (https://dx.doi.org/10.26186/150050). The AusBathyTopo 250m grid provides a high-resolution terrain model for Australia, covering ocean and land areas from 92°E to 172°E and 8°S to 60°S at a resolution of 250 metres. The bathymetric contours are clipped to the boundaries of the Australian Exclusive Economic Zone (EEZ: https://amsis-geoscience-au.hub.arcgis.com/datasets/geoscience-au::exclusive-economic-zone-limits/about), and includes all regions including and below Mean Sea Level (MSL). Four contour datasets are provided: 1) 100 m intervals: full EEZ coverage. 2) 5 m intervals: shallow regions between 0–200 m depth (nominally the Australian continental shelf and shallow oceanic features). 3) 1 m intervals: shallow regions between 0–200 m depth. 4) Composite product: Multi-resolution contours with full EEZ coverage, including: • 2 m intervals for depths 0–30 m. • 5 m intervals for depths 30–100 m. • 10 m intervals for depths 100–200 m. • 50 m intervals for depths 200–2,000 m. • 100 m intervals for depths 2,000–8,000 m. These contour datasets are intended for use in marine spatial planning, mapping visualisation, and broad-scale analysis. Due to the smoothing procedures applied during their creation the are not suitable for engineering or high-precision applications. The contours presented through the Web Mapping Services (WMS) linked to this record are optimised for visualisation purposes and have been simplified using a tolerance of 10 meters for efficient rendering in mapping applications. For users requiring full-resolution data, the download packages include the original, unsimplified contour products.

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    Perpendicular seismic refraction profiles collected at 11 sites along and across the ice flow unit boundary between ice units coming from the Lambert Glacier and the Mawson Escarpment Ice Stream. Survey sites are located upstream of Gillock Island.

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    Fine-scale bathymetry mapping was conducted in the Franklin and Zeehan Australian Marine Parks (AMPs) located off the west coast of Tasmania, Australia. The primary objective of this mapping exercise was to map seafloor features of the shelf areas of these AMPs for the first time and to understand the distribution of benthic habitats and key sessile invertebrate species within these areas. Characterisation of the seafloor was undertaken in two phases. The first stage used multibeam sonar to comprehensively map the study areas, extracting bathymetry and backscatter products. This was followed by extensive ground validation undertaken by a panoramic stereo drop-camera system that also recorded the presence of dominant sessile invertebrate fauna as well as benthic/demersal fish species. This record describes and provides data access to the fine-scale substratum mapping extracted from the combination of multibeam bathymetry and video ground-truthing data. Access to the (1) bathymetry survey data; and (2) annotated seafloor imagery, are provided through the 'Download and Links' section of this record.

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    The principle aim of this project was to map the fine-scale spatial distribution of key abalone habitat impacted by urchins in < 25 m water depth using multibeam acoustic imagery. Detailed substrate type (Pavement Reef, Megaclast Reef, Mixed Consolidated Sediment/Reef and Sand), and kelp coverage maps have been produced for the east coast of Tasmania. Large urchin barrens have been predicted and the minimum quantifiable unit of which small incipient barrens can be detected has been identified using this acoustic water column technique. This data provides a snapshot of the 2021 distribution of seafloor habitats and associated vegetation distribution, and will assist in the facilitation of strategic decision making for urchin control and abalone management. All spatial datasets and derivatives of the have been uploaded onto the Seamap Australia data portal for visualisation as a resource for both managers and scientists for further analysis and study. Data packages have been split by fishing block (22-24, 27-30) and are available to download from each of the 'child' records linked to this record (below).