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The Tasmanian Shelf survey was conducted on the Challenger in collaboration with the Tasmanian Aquaculture and Fisheries Institute between the 13-16th June, 2008 and 23rd February to the 14th March, 2009 (GA survey #0315). The survey was operated as part of the Surrogates Program of the CERF Marine Biodiversity Hub. The objective was to collect co-located physical and biological data to enable the robust testing of a range of physical parameters as surrogates of benthic biodiversity patterns. A total of 55 video transects were surveyed from five study areas (Tasman Peninsula, Freycinet Peninsula, The Friars, Huon river, and Port Arthur channel) in water depths ranging from 15-110 m. Video was recorded to mini DV tapes, and copied to digital format. For further information on this survey please refer to the post-survey report (GA Record 2009/043 - Geocat #69755).
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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.
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The Petrel Sub-basin Marine Survey GA-0335 (SOL5463) was acquired 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. Underwater video footage and still photographic images (12 megapixel resolution) from towed-video were acquired from 11 stations. The quality of imagery varies among transects and some still images were not of suitable quality for analysis. No still images are available for stations 2, 4 and 7 due to system malfunction. Video and still image files and associated parent folders are named by station number, gear code (CAM = underwater camera system) and then the deployment number. For example 'STN08CAM06' would represent a video transect from Station 08 that was the 6th video transect of the survey. Please note that the Ultra-short Baseline (USBL) acoustic tracking system used to track the towed-camera system failed early in the survey; hence geo-location of video transects and stills could only be linked to the R.V. Solander's ship navigation.
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The Vlaming Basin survey (GA survey # 334) was conducted under the Nation CO2 Infrastructure Plan (NCIP) on the MV Southern Supporter between the 12th to the 21st April 2012, with technical support provided from Fugro. The survey obtained geological (sedimentological, geochemical, geophysical) and biological data to support assessments of offshore acerage release areas for potential CO2 storage, and investigate the relationships between the physical environment and associated biota for biodiversity prediction. The purpose of the survey was to contribute to the assessment of the Vlaming Sub-basin for containment risk, as well as complement and validate interpretation of seismic data in the same area. Underwater footage was collected from 12 stations, although quality varies between sites and among transect lines. Video folders are named according to station number, followed by gear code (CAM=Ray Tech Underwater system), then the deployment number, and followed by region. For example, 12CAM02_D1 represents a video transect from station 12 that was the 2nd video transect of the survey and located in area region D1. Multiple files within transect folders indicate location metadata (Start of line location). In addition, USBL (Ultra-short baseline) text files located in the same folder provide continuous navigational information on location, time (UTC) and depth of each video transect line.
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The value of integrated high-resolution data sets in understanding the marine environment has been demonstrated in numerous studies around the Australian margin, however this approach has rarely been applied to studies in East Antarctica. This integrated approach was applied to a survey in Antarctica which utilised a multibeam sonar system, underwater video and sediment sampling to aid the understanding of seabed character and benthic biotopes in the coastal waters of the Vestfold Hills, near the Australian station of Davis. The Vestfold Hills is one of the largest ice-free areas on the East Antarctic coast. The coastal area is a complex of small islands, embayments and fjords. High-resolution bathymetry and backscatter data were collected over 42km2 to depths of 215 m. Epibenthic community data and in situ observations of seafloor morphology, substrate composition and bedforms were obtained from towed underwater video. The new high resolution datasets reveal a mosaic of rocky outcrops and sediment-filled basins. 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 benthic 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. Flat to gently sloping plains with a thin sandy cover on shallow bedrock 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 controls 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 an important driver of benthic community composition, with dense macroalgae communities only found where ice-free conditions persist for most of the summer. The bathymetry data shows iceberg scouring is common, however, scouring does not appear to impact benthic community composition in the study area. This is the first study that has used an integrated sampling approach to investigate benthic assemblages across a range of habitats in a coastal marine environment in East Antarctica. This study demonstrates the efficacy of using multibeam and towed video systems to survey large areas of the seafloor in Antarctica where marine sampling is often logistically difficult, 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 natural variability and human-induced change across the coastal marine environment (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.
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The extent to which low-frequency sound from marine seismic surveys impacts marine fauna is a subject of growing concern. The predominant frequency range of seismic airgun emissions is within the hearing range of cetaceans, reptiles, and fishes, and it can also elicit a neurological response in some invertebrates. Offshore seismic surveys have long been considered to be disruptive to fisheries, but comparatively few studies target commercially important species in realistic exposure scenarios. One of the main challenges in underwater sound impact studies is the meaningful translation of laboratory results to the field. Underwater sound properties are affected by the sound source, as well as characteristics of the water column, substrate, and biological communities. The experimental set-up is also critical in determining accurate response measurements, and design features of holding tanks can lead to misinterpretation of results, particularly related to behaviour. It may be tempting to simplify laboratory results to show effect or no effect, where results should instead be interpreted in the context of realistic exposure scenarios and field conditions. This project was developed in response to concerns raised by the fishing industry during stakeholder consultation in the lead up to a proposed seismic survey in the Gippsland Basin (Victoria, Australia), in addition to a broader need to acquire baseline data that may be used to quantify potential impacts of seismic operations on marine organisms. The project involves seven experimental components conducted before, during and after the seismic survey in both control and experimental areas of the Gippsland Basin: 1) Theoretical noise modelling, 2) Field-based noise monitoring and modelling, 3) Image acquisition by Autonomous Underwater Vehicle (AUV), 4) Bivalve sampling by dredging, 5) Fish movement analysis by tagging, 6) Catch rate analysis, and 7) Environmental modelling during the 2010 mortality event. In this presentation, we describe these components and critically review our current understanding of low-frequency sound impact on marine fish and invertebrates.
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National seascapes describing a layer of ecologically-meaningful biophysical properties that spatially represent potential seabed habitats have been derived for the Australian margin and adjacent seafloor. Seascapes were derived separately for the shelf and off-shelf regions due to different data availability. A total of 13 and 9 seascapes were derived for the on-shelf and off-shelf regions, respectively, using the unsupervised ISOCLASS classification in the software package ERMapper. Generally, the on-shelf seascapes divide into two broad latitudinal groups. The southern group (seascapes 1-7) is characterised by sandy, cooler environments relative to the northern group (seascape 9-13) which is characterised by muddier, warmer environments. Seascape 8 occurs predominantly on the west and east margins, separating the two groups. Off-shelf seascapes lack a distinct latitudinal pattern and their distribution is more related to seafloor temperature as a function of depth. For the deep-sea regions on the southern and western margins the seascapes are principally defined by rugosity and primary production. For other areas off-shelf seascape distribution is more complex and related to bathymetry and slope (rugosity).
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Description of sampling and data acquisition activites carried out by Geoscience Australia staff as part of an Australian Antarctic Division survey to the George V Land margin, Antarctica. The survey was part of the Census of Antarctic Marine Life Project.
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The Marine Science Voyage (2010/11 VMS) to the Mertz Glacier region was a collaborative survey involving scientists from a number of research institutions, working across a number of different projects, with the overall aim of conducting a coordinated and comprehensive study to measure and monitor the impact of the Mertz Glacier calving event on the local and regional environment. The survey took place in January 2011 and enabled the collection of data shortly after the calving event so that physical, chemical and biological changes in response to the new conditions can be monitored over time. As such, data collected on VMS will provide a benchmark for tracking future change in the Mertz Glacier region environment. Geoscience Australia and the Australian Antarctic Division conducted a benthic community survey during the voyage. The purpose of the benthic community survey was to collect high-resolution still images of the sea floor to address three main objectives: 1. to investigate benthic community composition in the area previously covered by the MGT and to the east, an area previously covered by approximately 30 m of fast ice; 2. to investigate benthic community composition (or lack thereof) in areas of known iceberg scours; and 3. to investigate the lateral extent of hydrocoral communities along the shelf break. The survey collected over 1800 images of the sea floor on the continental shelf and slope in the Mertz Glacier region, including in the area previously covered by the Mertz Glacier tongue. There were 75 successful camera deployments and a further 7 stations where images were of poor quality but may still provide useful information. The benthic images will be examined in detail to provide information on benthic community composition and substrate type. The survey has provided a major new set of data which will greatly enhance the understanding of Antarctic marine biodiversity and the relationship between physical conditions and benthic communities.
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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.