Characteristics of Sedimentary Organic Matter and Phosphorus in Minor Rivers Discharging into Zhejiang Coast, China

In this study, the spatial distribution of lignin-derived phenols, bulk elemental composition and different phosphorus (P) species in surface sediments along six rivers discharging into Zhejiang coast, Southeast China, were investigated to improve the understanding of the carbon and P dynamics in these small river systems. The Shuang, Jiao, Ximen, Feiyun and Ao Rivers have total organic carbon (TOC) ranging from 0.29% to 2.77% and Λ (total lignin in mg/100 mg TOC) ranging from 0.24 to 4.24; Qiantang River has the lowest Λ (0.08–0.19) but the highest TOC (1.05%–6.46%). Jiao, Ximen, Feiyun and Ao Rivers have mean the total P (TP) and bioavailable P (BAP) of 34 to 124 mg/kg and 29 to 89 mg P/kg, and mean OC/OP molar ratio of 397–917. Qiantang River has the lowest mean TP and BAP of 13 mg P/kg and 7 mg P/kg, and highest OC/OP of 18,753; whereas Shuang River has the highest mean TP and BAP of 645 mg P/kg and 559 mg P/kg, and lowest mean OC/OP of 90. The lowest Λ, TP and BAP, but highest OC/OP, in the Qiantang River could be due to tidal bore causing rapid cycling of carbon and P. Trends of slight decrease in abundance of OC, Λ, TP and BAP, but increasing ratios of vanillic acid to vanillin [(Ad/Al)v], syringic acid to syringaldehyde [(Ad/Al)s] and OC/OP farther downstream of the rivers indicate a continuous decomposition of organic matter during transport along the rivers.

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Relationships between microbial distributions and the anaerobic decomposition of organic matter in surface sediments of long Island Sound, USA

Marine Biology ◽

10.1007/bf00390591 ◽

1980 ◽

Vol 56 (1) ◽

pp. 29-42 ◽

Cited By ~ 118

Author(s):

R. C. Aller ◽

J. Y. Yingst

Keyword(s):

Organic Matter ◽

Surface Sediments ◽

Long Island ◽

Long Island Sound ◽

Anaerobic Decomposition ◽

Decomposition Of Organic Matter ◽

Island Sound

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Potential Eutrophication Associated with Phosphorus Inputs from Shrimp Effluents in a Tropical Estuary

Geochimica Brasiliensis ◽

10.21715/gb2358-2812.2021351076 ◽

2021 ◽

pp. 76-85

Author(s):

Rafael Aquino ◽

Susan Rodrigues ◽

Pedro Souza-Filho ◽

Silvia Kawakami

Keyword(s):

Organic Matter ◽

Surface Sediments ◽

Sediment Cores ◽

River Estuary ◽

Maximum Activity ◽

Shrimp Farming ◽

Depositional History ◽

P Accumulation ◽

Shrimp Farms ◽

Total P

Shrimp farming has been associated with eutrophication due to the generation of effluents enriched with organic matter and nutrients. Phosphorus (P) distribution was investigated in the Coreaú River Estuary (NE Brazil) using surface sediments and sediment cores. In surface sediments, total P concentrations ranged from 349.2 to 633.5 μg g-1 (mean = 465.2) and were about three times lower than those of other Brazilian estuaries impacted by larger shrimp cultures. The predominance of P forms in surface sediments followed the sequence: iron-bound P (Fe-P, 30%) > organic-P (Org-P, 23%) > exchangeable-P (Exch-P, 20%) > authigenic apatite (Ca-P, 15%) > detrital apatite (De-P, 12%). No significant correlation was observed between Exch-P and Fe-P (r = 0.389; p < 0.05). Highest Exch-P and Org-P concentrations and a strong correlation between these forms were found (r = 0.706, p < 0.05), suggesting the same sources of P and organic matter. Total P accumulation along the cores was 10,211 and 15,632 μg g-1 at the estuary mouth (T1) and the upper estuary (T2), respectively. T1 exhibited the predominant sequence: De-P (36%) > Ca-P (25%) > Fe-P (22%) > Exch-P (9%) > Org-P (7%); whereas T2 showed: Fe-P (31%) > De-P (23%) > Org-P (21%) > Ca-P (17%) > Exch-P (9%). Phosphorus depositional history points to P accumulation episodes at the end of the 1980 and mid-1990, coinciding with increasing urbanization and the beginning or maximum activity of the shrimp farms. Despite the low total P concentrations, the proportions of the labile forms Exch-P, Fe-P and Org-P in surface sediments indicated a trend to a high potential for eutrophication.

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Relationships between microbial distributions and the anaerobic decomposition of organic matter in surface sediments of Long Island Sound, USA

Deep Sea Research Part B Oceanographic Literature Review ◽

10.1016/0198-0254(80)96056-2 ◽

1980 ◽

Vol 27 (12) ◽

pp. 894

Keyword(s):

Organic Matter ◽

Surface Sediments ◽

Long Island ◽

Long Island Sound ◽

Anaerobic Decomposition ◽

Decomposition Of Organic Matter ◽

Island Sound

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Composition of Sedimentary Organic Matter across the Laptev Sea Shelf: Evidences from Rock-Eval Parameters and Molecular Indicators

Water ◽

10.3390/w12123511 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3511

Author(s):

Elena Gershelis ◽

Andrey Grinko ◽

Irina Oberemok ◽

Elizaveta Klevantseva ◽

Natalina Poltavskaya ◽

...

Keyword(s):

Organic Matter ◽

Surface Sediments ◽

Continental Margins ◽

Laptev Sea ◽

Lena River ◽

Nearshore Sediments ◽

Rock Eval ◽

Molecular Indicators ◽

Sedimentation Regime ◽

The Laptev Sea

Global warming in high latitudes causes destabilization of vulnerable permafrost deposits followed by massive thaw-release of organic carbon. Permafrost-derived carbon may be buried in the nearshore sediments, transported towards the deeper basins or degraded into the greenhouse gases, potentially initiating a positive feedback to climate change. In the present study, we aim to identify the sources, distribution and degradation state of organic matter (OM) stored in the surface sediments of the Laptev Sea (LS), which receives a large input of terrestrial carbon from both Lena River discharge and intense coastal erosion. We applied a suite of geochemical indicators including the Rock Eval parameters, traditionally used for the matured OM characterization, and terrestrial lipid biomarkers. In addition, we analyzed a comprehensive grain size data in order to assess hydrodynamic sedimentation regime across the LS shelf. Rock-Eval (RE) data characterize LS sedimentary OM with generally low hydrogen index (100–200 mg HC/g TOC) and oxygen index (200 and 300 CO2/g TOC) both increasing off to the continental slope. According to Tpeak values, there is a clear regional distinction between two groups (369–401 °C for the inner and mid shelf; 451–464 °C for the outer shelf). We suggest that permafrost-derived OM is traced across the shallow and mid depths with high Tpeak and slightly elevated HI values if compared to other Arctic continental margins. Molecular-based degradation indicators show a trend to more degraded terrestrial OC with increasing distance from the coast corroborating with RE results. However, we observed much less variation of the degradation markers down to the deeper sampling horizons, which supports the notion that the most active OM degradation in LS land-shelf system takes part during the cross-shelf transport, not while getting buried deeper.

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The riverine bioreactor: An integrative perspective on biological decomposition of organic matter across riverine habitats

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.145494 ◽

2021 ◽

Vol 772 ◽

pp. 145494

Author(s):

Ignacio Peralta-Maraver ◽

Rachel Stubbington ◽

Shai Arnon ◽

Pavel Kratina ◽

Stefan Krause ◽

...

Keyword(s):

Organic Matter ◽

Decomposition Of Organic Matter ◽

Riverine Habitats ◽

Biological Decomposition

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Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores

Scientific Reports ◽

10.1038/s41598-021-83651-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hidekazu Yoshida ◽

Ryusei Kuma ◽

Hitoshi Hasegawa ◽

Nagayoshi Katsuta ◽

Sin-iti Sirono ◽

...

Keyword(s):

Organic Matter ◽

Early Diagenesis ◽

Ph Change ◽

Carbon Preference Index ◽

Diffusion Growth ◽

Silica Precipitation ◽

Precipitated Silica ◽

Preference Index ◽

Decomposition Of Organic Matter ◽

Growth Diagram

AbstractIsolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

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Linking patterns of freshwater discharge and sources of organic matter within the Río de la Plata estuary and adjacent marshes

Marine and Freshwater Research ◽

10.1071/mf16286 ◽

2017 ◽

Vol 68 (9) ◽

pp. 1704 ◽

Cited By ~ 5

Author(s):

Leandro Bergamino ◽

Mark Schuerch ◽

Adriana Tudurí ◽

Silvina Carretero ◽

Felipe García-Rodríguez

Keyword(s):

Organic Matter ◽

Surface Sediments ◽

Sediment Cores ◽

Freshwater Discharge ◽

C3 Plants ◽

Estuarine System ◽

Rio De La Plata ◽

Río De La Plata ◽

La Plata ◽

Matter Transport

We investigated carbon isotopic ratios (δ13C) v. carbon to nitrogen (C : N) ratios for surface sediments throughout a large estuarine system (Río de la Plata, RdlP), combined with sediment cores from adjacent marshes to infer main carbon sources. We also evaluated the influence of the El Niño–Southern Oscillation (ENSO) and associated high freshwater-discharge events on the organic-matter transport within the estuary. The isotopic pattern in surface sediments of the RdlP showed the upper reaches to be influenced by riverine particulate matter (δ13C range: –24 to –26‰). Similarly, in the sediment cores from marshes of the upper reaches, δ13C values decreased from –24‰ in ancient sediments to –28‰ in recent sediments, reflecting an increased contribution of organic matter from land, including C3 plants and freshwater phytoplankton, during the past 50 years. However, the lower reaches represent a depositional environment of marine algae (δ13C range: –21 to –23‰), with no influence of detritus from adjacent marshes, indicating minor erosion of the marshes in the lower reaches operating as carbon-sink habitats. Our isotopic analysis showed that the transport and deposition of terrigenous organic matter within the RdlP and adjacent marsh habitat appear to be both temporally and spatially linked to hydrology patterns.

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