Oceanic Shoals Commonwealth Marine Reserve - Bulk organic carbon and nitrogen concentrations and isotopes in seabed sediment.

Brief description

This resource contains geochemistry data 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). This dataset comprises bulk organic carbon and nitrogen concentrations (and isotopes) from the upper 2 cm of seabed sediment. The Oceanic Shoals Commonwealth Marine Reserve survey was undertaken as an activity within the Australian Government's National Environmental Research Program Marine Biodiversity Hub and was the key component of Research Theme 4 - Regional Biodiversity Discovery to Support Marine Bioregional Plans. Hub partners involved in the survey included the Australian Institute of Marine Science, Geoscience Australia, the University of Western Australia, Museum Victoria and the Museum and Art Gallery of the Northern Territory. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; sub-bottom acoustic profiles; physical samples of seabed sediments, infauna and epibenthic biota; towed underwater video and still camera observations of seabed habitats; baited video observations of demersal and pelagic fish, and; oceanographic measurements of the water column from CTD (conductivity, temperature, depth) casts and from deployment of sea surface drifters. 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. 2013. Oceanic Shoals Commonwealth Marine Reserve (Timor Sea) Biodiversity Survey: GA0339/SOL5650 - Post Survey Report. Record 2013/38. Geoscience Australia: Canberra. (GEOCAT #76658).

Lineage

Maintenance and Update Frequency: asNeeded

Statement: Bottom sediments were collected using either a Smith McIntyre grab or a Box Core. Surface sediments (~0-2 cm) within the grab were spooned into falcon vials and the porewaters were removed by centrifugation. The samples were then frozen for transport to the laboratories at Geoscience Australia where they were freeze-dried, ground in a tungsten carbide mill and decarbonated. The decarbonated powders were sent to Environmental Isotopes Pty Ltd (Sydney) for isotopic analysis by mass spectrometry. Samples were back-corrected to account for the carbonate removal, using carbonate concentrations derived from the bomb method. Error estimates for the C and N isotope values are ±0.15. The carbonate measurements (used to back correct) were better than 5%. Thanks to the crew of the RV Solander for help with sample collection. Environmental Isotopes Pty. Sydney provided the analyses after sample processing by T. Watson and with the administrative support of J. Chen.