Seasonal Dynamics of Surface Dissolved Organic Matter in the South China Sea and the Straits of Malacca: Implications for Biogeochemical Province Delineation of Marginal Seas

Fe and Mn oxides and (oxy)-hydroxides are the most abundant solid-phase electron acceptors in marine sediments, and dissimilatory Fe/Mn reduction usually links with the anaerobic oxidation of methane (AOM) and organic matter oxidation (OMO) in sediments. In this study, we report the results from subsurface marine sediments in the Dongsha hydrate-bearing area in the South China Sea. The petrological and geochemical signatures show that the Fe/Mn reduction mediated by AOM and OMO might occur in sediments above the sulfate-methane transition zone. X-ray diffraction and scanning electron microscopy analyses of sediments indicate that Fe(III)/Mn(IV)-oxides and authigenic carbonate minerals coexisted in the Fe/Mn reduction zone. The lower δ13C values of dissolved inorganic carbon, coupled with an evident increase in total inorganic carbon contents and a decrease in Ca2+ and Mg2+ concentrations indicate the onset of AOM in this zone, and the greater variation of PO43− and NH4+ concentrations in pore water suggests the higher OMO rates in subsurface sediments. Geochemical and mineralogical analyses suggest that the previously buried Fe(III)/Mn(IV) oxides might be activated and lead to the onset of Fe/Mn reduction induced by AOM and OMO. These findings may extend our understanding of the biogeochemical processes involved in Fe/Mn reduction in continental shelves with abundant methane, organic matter, and terrigenous metal oxides.

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Composition of the organic matter of the water, suspended matter, and bottom sediments in Nha Trang Bay in Vietnam in the South China Sea

Oceanology ◽

10.1134/s0001437011060130 ◽

2011 ◽

Vol 51 (6) ◽

pp. 959-968 ◽

Cited By ~ 2

Author(s):

V. I. Peresypkin ◽

A. V. Smurov ◽

N. A. Shulga ◽

E. S. Safonova ◽

T. G. Smurova ◽

...

Keyword(s):

Organic Matter ◽

South China Sea ◽

Bottom Sediments ◽

South China ◽

Suspended Matter ◽

The South China Sea ◽

The South ◽

China Sea ◽

Nha Trang Bay

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Unchanged nitrogen isotopic composition of organic matter in the South China Sea during the last climatic cycle: Global implications

Paleoceanography ◽

10.1029/1999pa000407 ◽

2000 ◽

Vol 15 (2) ◽

pp. 244-253 ◽

Cited By ~ 83

Author(s):

Markus Kienast

Keyword(s):

Organic Matter ◽

South China Sea ◽

Isotopic Composition ◽

South China ◽

The South China Sea ◽

The South ◽

China Sea ◽

Climatic Cycle ◽

Nitrogen Isotopic Composition

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Diversity and biogeography of picoplankton communities from the Straits of Malacca to the South China Sea

Oceanological and Hydrobiological Studies ◽

10.1515/ohs-2020-0003 ◽

2020 ◽

Vol 49 (1) ◽

pp. 23-33

Author(s):

Zhao-Yu Jiang ◽

Fu-Lin Sun

Keyword(s):

Community Structure ◽

South China Sea ◽

South China ◽

Marine Ecosystem ◽

The South China Sea ◽

Rrna Genes ◽

The South ◽

China Sea ◽

Open Sea ◽

Straits Of Malacca

AbstractMarine picoplankton, including prokaryotic and eukaryotic picoplankton, drive many biogeochemical processes, such as carbon, nitrogen and sulfur cycles, making them crucial to the marine ecosystem. Despite the fact that picoplankton is prevalent, its diversity and spatial distribution from the Straits of Malacca (SM) to the South China Sea (SCS) remain poorly investigated. This work explores the phylogenetic diversity and community structure of picoplankton in relation to environmental factors from the SM to the SCS. To this end, the Illumina MiSeq sequencing technique was applied to 16S and 18S rRNA genes. The results showed significant differences in the dynamics of picoplankton between the open sea and the strait region. Proteobacteria and Cyanobacteria constituted a larger part of the prokaryotic group. Within Cyanobacteria, the abundance of Prochlorococcus in the open sea was significantly higher than that of Synechococcus, while the opposite trend was observed in the strait. Dinoflagellata, Cnidaria, Retaria, Tunicata, and Arthropoda dominated among the eukaryotic taxa. High-throughput sequencing data indicated that salinity, temperature and NO2-N were the key factors determining the prokaryotic community structure, while temperature and dissolved oxygen determined the eukaryotic community structure in the studied region. The network analysis demonstrated that the cooperation and competition were also important factors affecting the picoplankton community.

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State Practices in Southeast Asia: Possible Collaboration amongst Claimants in the South China Sea Dispute

The International Journal of Marine and Coastal Law ◽

10.1163/15718085-12322057 ◽

2017 ◽

Vol 32 (2) ◽

pp. 364-372 ◽

Cited By ~ 2

Author(s):

Arif Havas Oegroseno

Keyword(s):

South China Sea ◽

Southeast Asia ◽

South China ◽

The South China Sea ◽

Coral Triangle ◽

The South ◽

China Sea ◽

Joint Activities ◽

Territorial Sovereignty ◽

Straits Of Malacca

This article considers the prospects for cooperation between the claimants in the South China Sea dispute. A number of reasons are provided to explain why the likelihood of resolving the dispute over territorial sovereignty is slim. Nonetheless, such disagreements need not stand in the way of managing the South China Sea dispute. In this regard, inspiration is sought in other practices in Southeast Asia where joint activities are conducted in areas where not all maritime boundaries and sovereignty disputes have been settled. These practices are (1) the management of the Straits of Malacca and Singapore, and (2) the Coral Triangle Initiative. The author suggests that China and the asean member states should gain first-hand information about these practices with a view to establishing comparable joint activities in the South China Sea.

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