This web service contains sediment and geochemistry information for the Oceanic Shoals Commonwealth Marine Reserve (CMR) in the Timor Sea collected by Geoscience Australia during September and October 2012 on RV Solander (survey GA0339/SOL5650). Further information on the survey is available in the post-survey report published as Geoscience Australia Record 2013/38: Nichol, S.L., Howard, F.J.F., Kool, J., Stowar, M., Bouchet, P., Radke, L., Siwabessy, J., Przeslawski, R., Picard, K., Alvarez de Glasby, B., Colquhoun, J., Letessier, T. & Heyward, A.
Survey SOL5650/GA0339 was undertaken between 12 September and 6 October 2012, using the AIMS 35 m research vessel Solander with a science and technical support crew from AIMS, Geoscience Australia, University of Western Australia and the Museum and Art Gallery of the Northern Territory. The survey comprised a series of geophysical mapping and biophysical sampling activities in four areas within the Oceanic Shoals CMR. In each survey area, multibeam sonar data (bathymetry and backscatter) was collected to provide 100% spatial coverage, with sampling stations selected before the survey. Site selection used a spatially-balanced random stratified method (termed a Generalised Random-Tessellation Stratified [GRTS] design), that was weighted to shallow areas (<50 m water depth). Sampling included non-destructive techniques (towed underwater video, stills photography, baited underwater video) to record benthic and pelagic biota, plus physical sampling of sediments and epibenthic biota (grabs, benthic sled tows). Water column measurements (conductivity, temperature, turbidity) and sea surface samples were also taken at representative stations and during transits. To broadly characterise the sub-surface geology, shallow (<70 m) sub-surface data was collected across three of the survey areas with a sub-bottom profiler.
Sampling was undertaken at 70 stations across the four survey areas to characterise the geophysical and biological properties of the seabed and water column within each area; with sea surface samples collected at a further nine stations during transits. At each station, the type of sampling undertaken and the gear used was determined by the seabed composition, water depth and visibility. In particular, deployment of baited remote underwater video stations (BRUVS) was limited to water depths less than ~60 m due to high turbidity and low light conditions.
Sampling activities within the four survey areas included:
Towed underwater video transects at 52 stations to characterise seabed types and benthic communities;
Collection of replicate sediment samples at 61 stations for sedimentology, geochemistry and infauna analyses using either a Smith-McIntyre grab (29 stations) or a box corer (32 stations);
Benthic sled tows at 22 stations to sample epibenthos;
Deployment of BRUVS at 56 stations to characterise demersal fish communities;
Deployment of Stereo Imagery System for Shark and Tuna Assessments (SISSTAs) units at 120 stations to characterise pelagic fish communities;
Deployment of a Conductivity Temperature Depth (CTD) instrument at 63 stations to characterise water column properties, and;
Deployment of 10 ocean drifters to map surface ocean currents in the region.
A link to the post-survey report is available here: http://www.ga.gov.au/corporate_data/76658/Rec2013_038.pdf
You can also purchase hard copies of Geoscience Australia data and other products at http://www.ga.gov.au/products-services/how-to-order-products/sales-centre.html
