As part of Australian Government's National Low Emission Coal Initiative (NLECI) and National CO2 Infrastructure Plan (NCIP), Geoscience Australia (GA) has been assessing offshore sedimentary basins for their CO2 storage potential. These studies, scheduled for completion by 30 June 2015, aim to identify potential sites for the geological storage of CO2 and provide pre-competitive information for the development of CO2 transport and storage infrastructure near major emission sources. The basins targeted for these studies are the Bonaparte Basin (Petrel Sub-basin), Browse Basin, Perth Basin (Vlaming Sub-basin) and Gippsland Basin. GA completed a series of marine surveys over the Petrel and Vlaming sub-basins and the Browse Basin during 2012-2013, that acquired 2D reflection seismic, multibeam bathymetry/backscatter and sub-bottom profiling data, and seabed samples and video footages. The datasets have been analysed to inform the assessment of potential CO2 storage capacity and containment for each study area. Integrated interpretation of the seabed, shallow subsurface and deep basin data has assisted the identification of potential fluid migration features that may indicate seal breach and the presence of migration pathways. Data on seabed environments and ecological habitats will provide a baseline for an assessment of the potential impacts of CO2 injection and storage, and associated infrastructure development.

Physical and biological characteristics of benthic communities are analysed from underwater video footage collected across the George V Shelf during the 2007/2008 CEAMARC voyage. Benthic habitats are strongly structured by physical processes operating over a range of temporal and spatial scales. Iceberg scouring recurs over timescales of years to centuries along shallower parts of the shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf and cross-shelf flow of high salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit and filter feeding communities. Long term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are important factors in the structure of benthic communities across the George V Shelf. The modern shelf communities mapped in this study largely represent colonisation over the past 8,000-12,000 years, following retreat of the icesheet and glaciers at the end of the last glaciation. Recolonisation on this shelf may have occurred from two sources: deep-sea environments and possible shelf refugia on the Mertz and Adélie Banks. However, any open shelf area would have been subject to intense iceberg scouring. Understanding the timescales over which shelf communities have evolved and the physical factors which shape them will allow better prediction of the distribution of Antarctic shelf communities and their vulnerability to change. This knowledge can aid better management regimes for the Antarctic margin.

The seascape of the vast Australian continental margin is characterised by numerous submarine canyons that represent an equally vast array of geomorphic and oceanographic heterogeneity. Theoretically, this heterogeneity translates into habitats that may vary equally widely in their ecological characteristics. Here we describe the methodology to develop a framework to broadly derive estimates of potential habitat condition (¿suitability¿ sensu lato) for pelagic and epibenthic megafauna (including demersal fishes), and benthic infauna in all of Australia¿s known submarine canyons. We find that the high geomorphic and oceanographic diversity of submarine canyons creates a multitude of potential habitat types. In general, it appears that canyons may be particularly high-quality for benthic species. Canyons that incise the shelf tend to score higher in habitat potential than those confined to the slope. Canyons with particularly high habitat potential are located mainly off the Great Barrier Reef, the NSW coast, the eastern margin of Tasmania and Bass Strait, and on the southern margin. Many of these canyons have complex bottom topography, are likely to be productive, and have less intense sediment disturbance regimes. The framework presented here can be relevant ¿ once refined and comprehensively validated with ecological data - in a management and conservation context to identify canyons (or groups of canyons) that are likely to represent high-value habitat along a vast continental margin where marine planning decisions may require spatial prioritization decisions. <b>Citation:</b> Zhi Huang, Thomas A. Schlacher, Scott Nichol, Alan Williams, Franziska Althaus, Rudy Kloser, A conceptual surrogacy framework to evaluate the habitat potential of submarine canyons, <i>Progress in Oceanography</i>, Volume 169, 2018, Pages 199-213, ISSN 0079-6611, https://doi.org/10.1016/j.pocean.2017.11.007

Geoscience Australia carried out a marine survey on Carnarvon shelf (WA) in 2008 (SOL4769) to map seabed bathymetry and characterise benthic environments through co-located sampling of surface sediments and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wave-generated currents. Data and samples were acquired using the Australian Institute of Marine Science (AIMS) Research Vessel Solander. Bathymetric mapping, sampling and video transects were completed in three survey areas that extended seaward from Ningaloo Reef to the shelf edge, including: Mandu Creek (80 sq km); Point Cloates (281 sq km), and; Gnaraloo (321 sq km). Additional bathymetric mapping (but no sampling or video) was completed between Mandu creek and Point Cloates, covering 277 sq km and north of Mandu Creek, covering 79 sq km. Two oceanographic moorings were deployed in the Point Cloates survey area. The survey also mapped and sampled an area to the northeast of the Muiron Islands covering 52 sq km. TheGA0308_Carnarvon_SOL4976 folder contains video footage and still images. The MS databse, the Excel files are video characterisation datasets: Carnarvon_video data (export).mdb; all_substrata_tx.xls (transect level); all_substrata_patch.xls (patch level); all_benthos_tx.xls (transect level); all_benthos_patch.xls (patch level); Carnarvon_QAQC_VIDEOlog.doc (QAQC document); Attribute_metadata.xls (attribute definition). Underwater towed-video footage abd still images represent the raw data. Video characterisation datasets include percent cover of substrata and benthic taxa characterised at two spatial scales: transect scale (mean values per transect) and patch scale (mean values for each patch type within a transect).

An integrated analysis of geoscience information and benthos data has been used to identify benthic biotopes (seafloor habitats and associated communities) in the nearshore marine environment of the Vestfold Hills, East Antarctica. High-resolution bathymetry and backscatter data were collected over 42km2 to depths of 215 m using a multibeam sonar system. Epibenthic community data and in situ observations of seafloor morphology, substrate composition and bedforms were obtained from towed underwater video. Analysis of the datasets was used to identify statistically distinct benthic assemblages and describe the physical habitat characteristics related to each assemblage, with seven discrete biotopes identified. The biotopes include a range of habitat types including shallow coastal embayments and rocky outcrops which are dominated by dense macroalgae communities, and deep muddy basins which are dominated by mixed invertebrate communities. Transition zones comprising steep slopes provide habitat for sessile invertebrate communities. Areas of flat sandy plains are relatively barren. The relationship between benthic community composition and environmental parameters is complex with many variables (e.g. depth, substrate type, longitude, latitude and slope) contributing to differences in community composition. Depth and substrate type were identified as the main drivers of benthic community composition, however, depth is likely a proxy for other unmeasured depth-dependent parameters such as light availability, frequency of disturbance by ice, currents and/or food availability. Sea ice cover is also an important driver and the benthic community in areas of extended sea ice cover is comprised of sessile invertebrates and devoid of macroalgae. This is the first study that has used an integrated sampling approach based on multibeam sonar and towed underwater video to investigate benthic assemblages across a range of habitats in a nearshore marine environment in East Antarctica. This study demonstrates the efficacy of using multibeam sonar and towed video systems to survey large areas of the seafloor and to collect non-destructive high-resolution data in the sensitive Antarctic marine environment. The multibeam data provide a physical framework for understanding benthic habitats and the distribution of benthic communities. This research provides a baseline for assessing environmental change across the nearshore marine environment. This research provides a baseline for assessing natural variability and human induced change on nearshore marine benthic communities (Australian Antarctic Science Project AAS-2201), contributes to Geoscience Australia's Marine Environmental Baseline Program, and supports Australian Government objectives to manage and protect the Antarctic marine environment.

Physical and biological characteristics of benthic communities on the George V Shelf have been analysed from underwater camera footage collecting during Aurora Australis voyages in 2007/08 and 2010/11. The 2007/08 data revealed a high degree of variability in the benthic communities across the shelf, with the benthic habitats strongly structured by physical processes. Iceberg scouring recurs over timescales of years to centuries along shallower parts of this shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf and cross-shelf flow of high salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit and filter feeding communities. Long term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These interacting physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are important factors in the structure of benthic communities across the George V Shelf. In February 2010, iceberg B09B collided with the Mertz Glacier Tongue, removing about 80% or 78km from the protruding tongue. This event provided a rare opportunity to access a region previously covered by the glacier tongue, as well as regions to the east where dense fast ice has built up over decades, restricting access. The 2010/11 voyage imaged 3 stations which were previously beneath the floating tongue, as well as 9 stations covered by multi-year and annual fast ice since the mid 1970s.

Presentation to be delivered at the Western Australian Marine Science Institution Symposium, Fremantle, 21 February Abstract text: Geoscience Australia, as the Australian Government's geoscience agency, has a long history of marine environment mapping and research on the North West Shelf of Australia. In recent times, several data acquisition surveys have been completed and subsequent interpretive products have been produced under Commonwealth Government programmes, including: the Offshore Energy Security Program (2006-2011); the Marine Biodiversity Hub under the Commonwealth Environmental Research Facilities (CERF) and the National Environmental Research Program (NERP), and; the National CO2 Infrastructure Plan (NCIP, 2011-15). Collaborations, such as those facilitated by CERF and NERP, and with the Australian Institute of Marine Science (AIMS), have resulted in further work in the region. Areas of investigation have included the North Perth Basin, Bonaparte Gulf and Timor Sea. Using data from these surveys and other sources, GA is continuing to develop regional-scale seabed datasets, including bathymetry, geomorphology, sediment properties, seabed disturbance and seabed hardness that are publicly available via the internet. A pilot program was started in 2010 to collate and archive environmental data generated by the offshore petroleum industry, with a focus on the North West Shelf. Geoscience Australia is currently undertaking marine surveys to provide seabed environmental information to support assessments of the CO2 storage potential of several offshore sedimentary basins under NCIP. A marine survey over the Browse Basin in May 2013, to be undertaken in collaboration with the AIMS, will acquire high-resolution bathymetry and information on seabed and shallow subsurface geology and ecology. Follow-up surveys are also proposed during 2013-2015. The Browse survey results will be publicly released as a data package integrating existing and the newly acquired seabed data, and in a report to the Department of Resources Energy and Tourism on the CO2 storage potential of selected areas of the Browse Basin.

An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Critical to this undertaking is understanding the distribution of benthic assemblages. Our aim is to identify the areas where benthic marine assemblages are likely to differ in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by known species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 30 types of geomorphic features of the seabed, 846 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of MPAs. We found that for existing MPAs no ecoregion has their full range of environmental types represented and 12 ecoregions have no MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 7 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 119 locations with spatially restricted environmental types, which should be considered for inclusion in future MPAs.

This report provides a description of the CERF Marine Biodiversity Hub's survey of the Carnarvon Shelf, Western Australia, in August and September, 2008. The survey was a collaboration between the Australian Institute of Marine Science (AIMS) and Geoscience Australia (GA) aboard RV Solander, as part of the Hub's Surrogates Program. The purpose of field surveys in the Surrogates Program is to collect high-quality, accurately co-located data to enable the robust testing of a range of physical parameters as surrogates of patterns of benthic biodiversity in strategically selected, spatially discrete areas that are representative of much broader benthic environments. The report describes the methods employed in the survey and the datasets collected. Additional processing of most of the physical data (wave and current measurements, multibeam sonar bathymetry and backscatter, sediment grab samples, acoustic sediment profiles) and biological data (towed underwater video and stills photography, bottom sediment samples, near-bottom plankton samples) collected is required before comparative analysis between the data sets can commence. However, a number of initial interpretations of the physical data have been made and examples of the types of biota encountered in the towed video and stills photography and initial interpretations of the benthic communities encountered, are provided. The survey was focussed on three strategically selected study areas on the southern Carnarvon Shelf at Mandu, Point Cloates and Gnaraloo. A small additional area was also examined near the Muiron Islands, in the mouth of Exmouth Gulf, at the end of the survey.

Geoscience Australia has undertaken a classification of biophysical datasets to create seabed habitat maps (termed 'seascapes') for the Australian margin and adjacent sea floor. Seascapes describe a layer of ecologically meaningful biophysical properties that spatially represents potential seabed habitats. Each seascape area corresponds to a region of the seabed that contains similar biophysical properties and, by association, potential habitats and communities. This dataset is a seascape classification for the on-shelf zone of the North-west bioregion. The on-shelf zone is separated from the off-shelf zone due to the availability of the effective disturbance layer for the on-shelf zone only. Also, a higher resolution sea floor temperature layer has been used in the on-shelf analysis.