Baseline biogeochemical data from Australia’s continental margin links seabed sediments to water column characteristics  


Authors / CoAuthors

Radke, L. | Nicholas, T. | Thompson, P.A. | Li, J. | Raes, E. | Carey, M. | Atkinson, I. | Huang, Z. | Trafford, J. | Nichol, S.

Abstract

Surficial marine sediments are an important source of nutrients for productivity and biodiversity yet the biogeochemistry of these sediments is poorly known in Australia. Seabed samples were collected at >350 locations in Australia’s western, northern and eastern continental margins during federal government surveys (2007-2014). Parameters analysed included measures of organic matter (OM) source (δ13C, δ15N and C:N-ratios), concentration (total organic carbon (%TOC) and surface area normalised TOC (OC:SA)) and bioavailability (chlorin indices, total reactive chlorins, total oxygen uptake, total sediment metabolism (TSM), sediment oxygen demand (SOD) and SOD and TSM normalised to TOC). The aim of this study is to summarise these biogeochemical ‘baseline’ data, and make contextualised inferences about processes that govern the observed concentrations. The OM was mainly from marine sources and OC:SA broadly reflected water column productivity (MODIS). Approximately 40% of sediments were organic-poor by global standards reflecting seawater oligotrophy; ~12% were organic-rich due to benthic production, high water column productivity and pockmark formation. OM freshness varied due to pigment degradation in water columns and dilution with refractory OM in reworked sediments. δ15N values confirmed the importance of N2 fixation to Timor Sea productivity, and point to recycling of fixed nitrogen within food chains in Western Australia. <b>Citation:</b> Radke Lynda, Nicholas Tony, Thompson Peter A., Li Jin, Raes Eric, Carey Matthew, Atkinson Ian, Huang Zhi, Trafford Janice, Nichol Scott (2017) Baseline biogeochemical data from Australia’s continental margin links seabed sediments to water column characteristics. <i>Marine and Freshwater Research</i> <b>68</b>, 1593-1617. https://doi.org/10.1071/MF16219

Product Type

document

eCat Id

100112

Contact for the resource

  Point of contact

Commonwealth of Australia (Geoscience Australia)  
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

  Resource provider

 

  Point of contact

 
Contact instructions
Place and Communities

Keywords

theme.ANZRC Fields of Research.rdf
  • EARTH SCIENCES
  • diazotroph
  • particulate
  • organic carbon
  • totol nitrogen
  • Trichodesmium
  • marine, geochemistry, seabed, sediments
  • Published_External

Publication Date

2024-05-22T22:44:31

Creation Date

Security Constraints

Classification - unclassified

Legal Constraints

Creative Commons NonCommercial NoDerivs International Licence    

Access - license

Use - license

Status

completed

Purpose

Manuscript to be submitted to Marine and Freshwater Research

Maintenance Information

asNeeded

Topic Category

oceans

Series Information

Marine and Freshwater Research Volume 68, 2017 1593-1617

Lineage

Manuscript to be submitted to Marine and Freshwater Research

Parent Information

Extents

[-54.75, -9.2402, 112.92, 159.11]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

Link to Journal  

Source Information