scholarly journals Remineralization of particulate organic carbon in an ocean oxygen minimum zone

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
E. L. Cavan ◽  
M. Trimmer ◽  
F. Shelley ◽  
R. Sanders
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Oxygen Minimum Zone ◽  
Minimum Zone ◽  
Oxygen Minimum

scholarly journals Macrobenthic assemblage structure and organismal stoichiometry control faunal processing of particulate organic carbon and nitrogen in oxygen minimum zone sediments

2012 ◽  
Vol 9 (3) ◽  
pp. 993-1006 ◽  
Author(s):  
W. R. Hunter ◽  
L. A. Levin ◽  
H. Kitazato ◽  
U. Witte
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Oxygen Minimum Zone ◽  
Oxygen Availability ◽  
Assemblage Structure ◽  
Sediment Geochemistry ◽  
Sea Floor ◽  
Carbon And Nitrogen ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. The Arabian Sea oxygen minimum zone (OMZ) impinges on the western Indian continental margin between 150 and 1500 m, causing gradients in oxygen availability and sediment geochemistry at the sea floor. Oxygen availability and sediment geochemistry are important factors structuring macrofaunal assemblages in marine sediments. However, relationships between macrofaunal assemblage structure and sea-floor carbon and nitrogen cycling are poorly understood. We conducted in situ 13C:15N tracer experiments in the OMZ core (540 m [O2] = 0.35 μmol l–1) and lower OMZ boundary (800–1100 m, [O2] = 2.2–15.0 μmol l–1) to investigate how macrofaunal assemblage structure, affected by different oxygen levels, and C:N coupling influence the fate of particulate organic matter. No macrofauna were present in the OMZ core. Within the OMZ boundary, relatively high abundance and biomass resulted in the highest macrofaunal assimilation of particulate organic carbon (POC) and nitrogen (PON) at the lower oxygen 800 m stations ([O2] = 2.2–2.36 μmol l–1). At these stations the numerically dominant cirratulid polychaetes exhibited greatest POC and PON uptake. By contrast, at the higher oxygen 1100 m station ([O2] = 15.0 μmol l–1) macrofaunal C and N assimilation was lower, with POC assimilation dominated by one large solitary ascidian. Macrofaunal POC and PON assimilation were influenced by changes in oxygen availability, and significantly correlated to differences in macrofaunal assemblage structure between stations. However, macrofaunal feeding responses were ultimately characterised by preferential organic nitrogen assimilation, relative to their internal C:N budgets.

scholarly journals Macrobenthic assemblage structure and organismal stoichiometry control faunal processing of particulate organic carbon and nitrogen in oxygen minimum zone sediments

2011 ◽  
Vol 8 (5) ◽  
pp. 10725-10760
Author(s):  
W. R. Hunter ◽  
L. A. Levin ◽  
H. Kitazato ◽  
U. Witte
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Oxygen Minimum Zone ◽  
Oxygen Availability ◽  
Assemblage Structure ◽  
Sediment Geochemistry ◽  
Sea Floor ◽  
Carbon And Nitrogen ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. The Arabian Sea oxygen minimum zone (OMZ) impinges on the western Indian continental margin between 150 and 1500 m, causing gradients in oxygen availability and sediment geochemistry at the sea floor. Oxygen availability and sediment geochemistry are important factors structuring macrofaunal assemblages in marine sediments. However, relationships between macrofaunal assemblage structure and sea-floor carbon and nitrogen cycling are poorly understood. We conducted in situ 13C:15N tracer experiments in the OMZ core (540 m [O2] = 0.35 μmol l−1) and lower OMZ boundary (800–1100 m, [O2] = 2.2–15.0 μmol l−1) to investigate how macrofaunal assemblage structure, affected by different oxygen levels, and C:N coupling influence the fate of particulate organic matter. No fauna were present in the OMZ core. Within the OMZ boundary, relatively high abundance and biomass resulted in the highest macrofaunal assimilation of particulate organic carbon (POC) and nitrogen (PON) at the lower oxygen 800 m stations ([O2] = 2.2–2.65 μmol l−1). At these stations the numerically dominant cirratulid polychaetes exhibited greatest POC and PON uptake. By contrast, at the higher oxygen 1100 m station ([O2] = 15.0 μmol l−1) macrofaunal C and N assimilation was lower, with POC assimilation dominated by one large solitary ascidian. Macrofaunal POC and PON assimilation were influenced by changes in oxygen availability, and significantly correlated to differences in macrofaunal assemblage structure between stations. POC and PON assimilation was characterised by carbon accumulation within the macrofauna, suggesting the importance of anaerobic metabolism at all stations. However, macrofaunal feeding responses were ultimately characterised by preferential organic nitrogen assimilation, relative to their internal C:N budgets.

scholarly journals Dark carbon fixation in the Arabian Sea oxygen minimum zone contributes to sedimentary organic carbon (SOM)

2019 ◽  
Vol 33 (12) ◽  
pp. 1715-1732 ◽  
Author(s):  
Sabine K. Lengger ◽  
Darci Rush ◽  
Jan Peter Mayser ◽  
Jerome Blewett ◽  
Rachel Schwartz‐Narbonne ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Arabian Sea ◽  
Carbon Fixation ◽  
Oxygen Minimum Zone ◽  
Sedimentary Organic Carbon ◽  
Minimum Zone ◽  
Dark Carbon Fixation ◽  
Oxygen Minimum

scholarly journals Fermentation and Anaerobic Oxidation of Organic Carbon in the Oxygen Minimum Zone of the Upwelling Ecosystem Off Concepción, in Central Chile

2020 ◽  
Vol 7 ◽  
Author(s):  
Benjamín M. Srain ◽  
Marcus Sobarzo ◽  
Giovanni Daneri ◽  
Humberto E. González ◽  
Giovanni Testa ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Oxygen Minimum Zone ◽  
Anaerobic Oxidation ◽  
Central Chile ◽  
Minimum Zone ◽  
Oxygen Minimum

scholarly journals Structure and function of nematode communities across the Indian western continental margin and its oxygen minimum zone

2016 ◽  
Vol 13 (1) ◽  
pp. 191-209 ◽  
Author(s):  
R. Singh ◽  
B. S. Ingole
Keyword(s):  
Organic Carbon ◽  
Continental Margin ◽  
Environmental Variables ◽  
Oxygen Minimum Zone ◽  
Structure And Function ◽  
Depth Range ◽  
Nematode Communities ◽  
Minimum Zone ◽  
And Function ◽  
Oxygen Minimum

Abstract. We studied patterns of nematode distribution along the western Indian continental margin to determine the influence of habitat heterogeneity and low oxygen levels on the community's taxonomic and functional structure. A single transect, perpendicular to the coast at 14° N latitude was sampled from 34 to 2546 m depth for biological and environmental variables during August 2007. The oxygen minimum zone extended from 102 to 1001 m. Nematodes (described and undescribed) were identified to species and classified according to biological and functional traits. A total of 110 nematode species belonging to 24 families were found along the transect. Three depth zones were identified: the shelf (depth range: 34–102 m; highest nematode mean density: 176.6 ± 37 ind 10 cm−2), the slope (525–1524 m; 124.3 ± 16 ind 10 cm−2), and the basin (2001–2546 m; 62.9 ± 2 ind 10 cm−2). Across the entire study area, the dominant species were Terschellingia longicaudata, Desmodora sp. 1, Sphaerolaimus gracilis, and Theristus ensifer; their maximum density was at shelf stations. Nematode communities in different zones differed in species composition. Chromadorita sp. 2 (2.78 %) and Sphaerolaimus gracilis (2.21 %) were dominant on the shelf, whereas Terschellingia longicaudata (4.73 %) and Desmodora sp. 1 (4.42 %) were dominant on the slope, but in the basin, Halalaimus sp. 1(1.11 %) and Acantholaimus elegans (1.11 %) were dominant. The information in a particular functional group was not a simple reflection of the information in species abundance. Ecological information captured by adult length, adult shape, and life-history strategy was less site-specific and thus differed notably from information contained in other taxonomic groups. The functional composition of nematodes was strongly linked to the organic-carbon and dissolved-oxygen concentration. Seven species were found exclusively in the oxygen minimum zone: Pselionema sp. 1, Choanolaimus sp. 2, Halichoanolaimus sp. 1, Cobbia dentata, Daptonema sp. 1, Trissonchulus sp. 1, and Minolaimus sp. 1. Correlation with a number of environmental variables indicated that food quantity (measured as the organic-carbon content and chlorophyll content) and oxygen level were the major factors that influenced nematode community structure and function.

scholarly journals Dark carbon fixation contributes to sedimentary organic carbon in the Arabian Sea oxygen minimum zone

2019 ◽  
Author(s):  
Sabine Lengger ◽  
Darci Rush ◽  
Jan Mayser ◽  
Jerome Blewett ◽  
Rachel Schwartz-Narbonne ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Arabian Sea ◽  
Carbon Fixation ◽  
Oxygen Minimum Zone ◽  
Sedimentary Organic Carbon ◽  
Minimum Zone ◽  
Dark Carbon Fixation ◽  
Oxygen Minimum
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