Carbon and nitrogen isotopic ratios of suspended particulate organic matter (SPOM) in the Black Sea water column

Çoban-Yıldız, Yeşim; Altabet, Mark A.; Yılmaz, Ali Özgür; Tuğrul, Süleyman

doi:10.1016/j.dsr2.2006.03.021

Cited by 61 publications

(45 citation statements)

References 58 publications

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“…4d) confirms the occurrence of chemolithoautotrophic production leading to predominantly organic matter produced in situ. A similar pattern was found by Coban-Yildiz et al (2006) in the Black Sea. A plot of C: N vs. δ 13 Corg -POM lead us to exclude the possibility of terrestrial influence, despite the proximity of our station to the coast (18 nm) and its location over the continental shelf, receiving high fresh water discharges from the Bio Bio River, mostly in wintertime.…”

Section: What Is the Relative Importance Of Chemo-vs Photoautotrophisupporting

confidence: 66%

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N2O and CH4 in an upwelling ecosystem

Farı́as¹,

Fernández

Faúndez³

et al. 2009

Biogeosciences

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Abstract. The high availability of electron donors occurring in coastal upwelling ecosystems with marked oxyclines favours chemoautotrophy, in turn leading to high N 2 O and CH 4 cycling associated with aerobic NH + 4 (AAO) and CH 4 oxidation (AMO). This is the case of the highly productive coastal upwelling area off central Chile (36 • S), where we evaluated the importance of total chemolithoautotrophic vs. photoautotrophic production, the specific contributions of AAO and AMO to chemosynthesis and their role in gas cycling. Chemolithoautotrophy was studied at a time-series station during monthly (2007)(2008)(2009)) and seasonal cruises (January 2008, September 2008, January 2009) and was assessed in terms of the natural C isotopic ratio of particulate organic carbon (δ 13 POC), total and specific (associated with AAO and AMO) dark carbon assimilation (CA), and N 2 O and CH 4 cycling experiments. At the oxycline, δ 13 POC averaged −22.2‰; this was significantly lighter compared to the surface (−19.7‰) and bottom layers (−20.7‰). Total integrated dark CA in the whole water column fluctuated between 19.4 and 2.924 mg C m −2 d −1 , was higher during active upwelling, and contributed 0.7 to 49.7% of the total integrated autotrophic CA (photo plus chemoautotrophy), which ranged from 135 to 7.626 mg C m −2 d −1 , and averaged 20.3% for the whole sampling period. Dark CA was reduced by 27 to 48% after adding a specific AAO inhibitor (ATU) and by 24 to 76% with GC7, a specific archaea inhibitor. This indicates that AAO and AMO microbes (most of them archaea) were performing dark CA through the oxidation of NH

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Section: What Is the Relative Importance Of Chemo-vs Photoautotrophisupporting

confidence: 66%

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N2O and CH4 in an upwelling ecosystem

Farı́as¹,

Fernández

Faúndez³

et al. 2009

Biogeosciences

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“…Thus, this process alone cannot explain the much lower N isotope values, down to -6%, reported for Archean sediments (Beaumont and Robert 1999;Pinti and Hashizume 2001;Papineau et al 2005;Pinti et al 2009). One model for generating 15 N-depleted values in anoxic systems (e.g., Fry et al 1991;Voss et al 1997;Coban-Yildiz et al 2006;Junium and Arthur 2007;Papineau et al 2009) invokes the uptake of isotopically light ammonium formed by the degradation of organic N in sediments and in the lower part of the water column.…”

Section: Sources Of Negative D 15 N Values In the Archean Biospherementioning

confidence: 99%

Geological constraints on the origin of oxygenic photosynthesis

2010

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This article examines the geological evidence for the rise of atmospheric oxygen and the origin of oxygenic photosynthesis. The evidence for the rise of atmospheric oxygen places a minimum time constraint before which oxygenic photosynthesis must have developed, and was subsequently established as the primary control on the atmospheric oxygen level. The geological evidence places the global rise of atmospheric oxygen, termed the Great Oxidation Event (GOE), between ~2.45 and ~2.32 Ga, and it is captured within the Duitschland Formation, which shows a transition from mass-independent to mass-dependent sulfur isotope fractionation. The rise of atmospheric oxygen during this interval is closely associated with a number of environmental changes, such as glaciations and intense continental weathering, and led to dramatic changes in the oxidation state of the ocean and the seawater inventory of transition elements. There are other features of the geologic record predating the GOE by as much as 200-300 million years, perhaps extending as far back as the Mesoarchean-Neoarchean boundary at 2.8 Ga, that suggest the presence of low level, transient or local, oxygenation. If verified, these features would not only imply an earlier origin for oxygenic photosynthesis, but also require a mechanism to decouple oxygen production from oxidation of Earth's surface environments. Most hypotheses for the GOE suggest that oxygen production by oxygenic photosynthesis is a precondition for the rise of oxygen, but that a synchronous change in atmospheric oxygen level is not required by the onset of this oxygen source. The potential lag-time in the response of Earth surface environments is related to the way that oxygen sinks, such as reduced Fe and sulfur compounds, respond to oxygen production. Changes in oxygen level imply an imbalance in the sources and sinks for oxygen. Changes in the cycling of oxygen have occurred at various times before and after the GOE, and do not appear to require corresponding changes in the intensity of oxygenic photosynthesis. The available geological constraints for these changes do not, however, disallow a direct role for this metabolism. The geological evidence for early oxygen and hypotheses for the controls on oxygen level are the basis for the interpretation of photosynthetic oxygen production as examined in this review.

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“…The negative δ 15 N in S5 is unusual even if N 2 -fixation and/or incomplete nitrate utilization occurred, and we speculate that another source of isotopically light nitrogen may have contributed to sedimentary N: recent studies in the Black Sea, which is permanently anoxic at depth and thus may be a suitable analogue for the S5 situation in the EMS, revealed that appreciable amounts of depleted particulate N must be produced by chemoautotrophic bacteria at the transition from suboxic to anoxic waters (Fry et al, 1991;Coban-Yildiz et al, 2006). This production is sustained by either assimilation of ammonia (Fry et al, 1991;Coban-Yildiz et al, 2006) or may derive from chemoautotrophic fixation of N 2 (McCarthy et al, 2007;Fuchsman et al, 2008) (Hoch et al, 1992;Voss et al, 1997), explaining the extremely low δ 15 N values of bacterial biomass.…”

Section: Alternative Explanations For 15 N Depletion In Sapropelsmentioning

confidence: 99%

“…This production is sustained by either assimilation of ammonia (Fry et al, 1991;Coban-Yildiz et al, 2006) or may derive from chemoautotrophic fixation of N 2 (McCarthy et al, 2007;Fuchsman et al, 2008) (Hoch et al, 1992;Voss et al, 1997), explaining the extremely low δ 15 N values of bacterial biomass.…”

Section: Alternative Explanations For 15 N Depletion In Sapropelsmentioning

confidence: 99%

Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

2010

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Abstract. The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually low δ 15 N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and δ 15 N in sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10-6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in δ 15 N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) present day TOC export production would suffice to create a sapropel like S1 under conditions of deepwater anoxia. This implies that both enhanced TOC accumulation and 15 N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt on the need of enhanced primary production for sapropel formation.

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Carbon and nitrogen isotopic ratios of suspended particulate organic matter (SPOM) in the Black Sea water column

Cited by 61 publications

References 58 publications

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N<sub>2</sub>O and CH<sub>4</sub> in an upwelling ecosystem

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N<sub>2</sub>O and CH<sub>4</sub> in an upwelling ecosystem

Geological constraints on the origin of oxygenic photosynthesis

Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

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Carbon and nitrogen isotopic ratios of suspended particulate organic matter (SPOM) in the Black Sea water column

Cited by 61 publications

References 58 publications

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N&lt;sub&gt;2&lt;/sub&gt;O and CH&lt;sub&gt;4&lt;/sub&gt; in an upwelling ecosystem

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N&lt;sub&gt;2&lt;/sub&gt;O and CH&lt;sub&gt;4&lt;/sub&gt; in an upwelling ecosystem

Geological constraints on the origin of oxygenic photosynthesis

Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

Contact Info

Product

Resources

About

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N<sub>2</sub>O and CH<sub>4</sub> in an upwelling ecosystem

Chemolithoautotrophic production mediating the cycling of the greenhouse gases N<sub>2</sub>O and CH<sub>4</sub> in an upwelling ecosystem