Evidence of terrestrial organic carbon inputs on Niger Delta Sea Shelf

2021 ◽  
Vol 19 (3) ◽  
pp. 83-100
Author(s):  
M.U. Uzoegbu
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Niger Delta ◽  
Organic Nitrogen ◽  
Constant Ratio ◽  
Sedimentation Pattern ◽  
Δ13c Values ◽  
Shelf Sediments ◽  
Niger River ◽  
River Niger

The objective of this research is to determine the actual source of organic matter in the Niger Delta Sea Shelf (NDSS). Organic carbon (OC) and n-alkanes were investigated in the suspended matter (SM) and surfcial sediments of the Niger and Imo Rivers and the opposite Niger Delta Sea Shelf. Organic nitrogen and carbon isotope (δ13C) values were determined as additional parameters in the sediments. OC and n-alkane concentrations were highly variable. This variability was interpreted as the result of sources of materials from the inland basins and a complex sedimentation pattern involving the discharges of these two rivers. Using the constant ratio of high molecular weight odd n-alkanes to OC in both rivers, the estimated value of more than 70% of the OC preserved in shelf sediments were terrestrially-derived. This result was substantiated by the overall dominance of land-derived n-alkanes. A second approach using δ13C values and assuming binary dilution of riverine and marine OC led to the determined source of organic matter. Keywords: Organic carbon; δ13C; n-Alkanes; Niger River; Imo River; Niger Delta Sea Shelf. 

scholarly journals Mineralization of soil organic nitrogen under waterlogged conditions in relation to other properties of tropical rice soils

Soil Research ◽  
1983 ◽  
Vol 21 (2) ◽  
pp. 133 ◽  
Author(s):  
KL Sahrawat
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Properties ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Wetland Rice ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Wide Range ◽  
Mineralizable Nitrogen

The mineralizable nitrogen pool in wetland rice soils plays a dominant role in the nitrogen nutrition of rice even in fertilized paddies. There is a lack of information on how different soil properties affect ammonification of organic nitrogen in wetland rice soils. Surface samples of 39 diverse Philippine soils representing a wide range of pH, organic matter and texture were studied to determine the relationships between ammonification of organic nitrogen and soil properties. Simple correlation analysis showed that ammonium production was correlated highly significantly with total nitrogen (r = 0.94**), organic carbon (r = 0.91**) and C/N ratio (r = -0.46**), but it was not significantly correlated with cation exchange capacity, clay or pH. Multiple regression analayses showed that organic matter (organic carbon and total nitrogen) accounted for most of the variation in mineralizable nitrogen. These results suggest that organic carbon content is a good index of mineralizable nitrogen in tropical wetland rice soils.

Proteins: Amino Acids and Amines

2011 ◽  
Author(s):  
Thomas S. Bianchi ◽  
Elizabeth A. Canuel
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Particulate Organic Carbon ◽  
Nitrogen Cycle ◽  
Organic Nitrogen ◽  
Building Blocks ◽  
Marine Organisms ◽  
Carbon And Nitrogen

This chapter discusses proteins, which make up approximately 50% of organic matter and contain about 85% of the organic nitrogen in marine organisms. Peptides and proteins comprise an important fraction of the particulate organic carbon (13–37%) and particulate organic nitrogen (30–81%), as well as dissolved organic nitrogen (5–20%) and dissolved organic carbon (3–4%) in oceanic and coastal waters. In sediments, proteins account for approximately 7 to 25% of organic carbon and an estimated 30 to 90% of total nitrogen. Amino acids are the basic building blocks of proteins. This class of compounds is essential to all organisms and represents one of the most important components in the organic nitrogen cycle. Amino acids represent one of the most labile pools of organic carbon and nitrogen.

Studies on soil organic matter: Part III. The extraction of organic carbon and nitrogen from soil

1949 ◽  
Vol 39 (3) ◽  
pp. 280-282 ◽  
Author(s):  
J. M. Bremner
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Organic Nitrogen ◽  
Carbon And Nitrogen

A study has been made of the extraction of organic carbon and nitrogen from soil by various inorganic reagents. The results show that the organic carbon and nitrogen of soil are so intimately associated that, under the influence of any one of the reagents tested, the organic carbon is dissolved only along with, and in proportion to, the organic nitrogen. The relative proportions of carbon and nitrogen extracted vary, however, with both the soil and the extractant.

Impact of Wastewater Treatment Processes on Organic Carbon, Organic Nitrogen, and DBP Precursors in Effluent Organic Matter

2009 ◽  
Vol 43 (8) ◽  
pp. 2911-2918 ◽  
Author(s):  
Stuart W. Krasner ◽  
Paul Westerhoff ◽  
Baiyang Chen ◽  
Bruce E. Rittmann ◽  
Seong-Nam Nam ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Organic Carbon ◽  
Organic Nitrogen ◽  
Effluent Organic Matter ◽  
Treatment Processes

Carbon and nitrogen content of food and the assimilation efficiencies of penaeid prawns in the Gulf of Carpentaria

1981 ◽  
Vol 32 (2) ◽  
pp. 245 ◽  
Author(s):  
DJW Moriarty ◽  
MC Barclay
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Organic Nitrogen ◽  
Inorganic Carbon ◽  
Bacterial Biomass ◽  
Muramic Acid ◽  
Carbon And Nitrogen ◽  
Growing Seasons ◽  
Organic And Inorganic Carbon ◽  
Carbon And Nitrogen Content

The food of seven species of penaeid prawns from the Gulf of Carpentaria consists predominantly of Foraminifera, small molluscs, crustaceans and polychaetes. Measurements of organic and inorganic carbon, organic nitrogen and bacterial biomass were made. Foregut contents of adult prawns contained between 72 and 223 mg organic carbon/g dry wt. Protein constituted between 43 and 64% of the organic matter. Approximate assimilation efficiencies of food in prawns caught in the gulf, determined for four species, varied from 48 to 77% of organic carbon and from 42 to 77% of organic nitrogen. The food of juvenile Penaeus merguiensis was examined for two growing seasons. In the 1976-1977 season the foregut contents contained a mean of 41 mg organic nitrogen /g dry wt and 181 mg organic carbon /g dry wt. In the 1977-1978 season, significantly lower proportions of organic nitrogen and carbon were eaten, viz, 21 mg organic nitrogenlg dry wt and 101 mg organic carbon /g dry wt. Improved assay procedures for muramic acid have shown that bacteria are less important in the food of prawns than previously reported. Bacteria constituted less than 2% of the organic matter in the adults of all species, but in many juvenile P. merguiensis bacteria were more important, constituting up to 14% of organic matter.

Feeding of Holothuria atra and Stichopus chloronotus on bacteria, organic carbon and organic nitrogen in sediments of the Great Barrier Reef

1982 ◽  
Vol 33 (2) ◽  
pp. 255 ◽  
Author(s):  
DJW Moriarty
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Great Barrier Reef ◽  
Organic Nitrogen ◽  
Bacterial Biomass ◽  
Gut Contents ◽  
Barrier Reef ◽  
Muramic Acid ◽  
Blue Green Algae ◽  
Carbon And Nitrogen

Organic carbon and nitrogen and bacterial biomass were measured in the sediments and gut contents of H. atra and S. chloronotuson the Great Barrier Reef. Organic carbon averaged from 3.4 to 4.7 mg g-1, organic nitrogen from 0.20 to 0.31 mg g-1 and muramic acid from 1.4 to 3.3�g g-1 dry weight of surface sandy sediments. Bacterial biomass, determined by muramic acid measurements, averaged 3-8% of organic carbon in the sediments; blue-green algae accounted for 3-7% of muramic acid. Significantly higher values of organic carbon and nitrogen and muramic acid were found in foregut contents of the holothurians, indicating selective feeding on organically rich components of the sediment. Carbon values were 16-34% higher in the foregut than in the sediment. nitrogen values 35-111% higher and muramic acid values 33-300% higher. These values indicate that bacteria and nitrogenous components of the organic matter were selectively eaten. Values for organic carbon and nitrogen and muramic acid were generally lower in the hindgut than in the foregut, due to digestion and assimilation. Assimilation efficiencies averaged 30% for organic carbon, 40% for organic nitrogen and 30-40% for muramic acid (bacteria). Detritus (non-living matter) probably constituted 60-80% of the organic matter in the sediment and thus the food of the holothurians.

Mercury in the Sediments of the Gulf of St. Lawrence

1975 ◽  
Vol 12 (7) ◽  
pp. 1219-1237 ◽  
Author(s):  
D. H. Loring
Keyword(s):  
Organic Matter ◽  
Total Mercury ◽  
Terrestrial Organic Matter ◽  
Sedimentation Pattern ◽  
Lawrence Estuary ◽  
Fine Grained ◽  
Depositional Processes ◽  
Saguenay Fjord ◽  
Shelf Sediments ◽  
St Lawrence Estuary

In sediments collected from the Saguenay fjord, the St. Lawrence estuary, and open Gulf of St. Lawrence, total mercury varies with sediment texture and location from 10 to 12 300 ppb (average 386 ppb). The highest concentrations occur in the Saguenay fjord (average 2980 ppb) and the lowest in the open Gulf of St. Lawrence (average 150 ppb). The concentration of mercury increases with decreasing grain size, the highest concentrations occur in the fine-grained sediments of the submarine troughs and shelf valleys and the lowest in the sandy shelf sediments. Analyses of the sediments from the Saguenay fjord, where mercury values range from 12 300 ppb at its head to > 500 ppb in the lower reaches, indicate that most of the mercury (70 to 90% of the total) is held by the organic matter in the sediments. The distribution of mercury in the fjord is apparently controlled by the downstream dispersal from local industrial sources of mercury-rich organic matter, most likely of terrestrial origin because of its high C/N ratio. In the St. Lawrence estuary where mercury values range from 30 to 950 ppb, and in the open Gulf where correlations between variables are lower and scattered anomalies exist, analyses indicate that mercury accumulates along with the fine-grained inorganic and organic matter in response to the present depositional processes. The distribution of mercury appears to be controlled by the sedimentation pattern. Terrestrial organic matter and industrial waste originating in the Saguenay drainage area have the strongest influence on its distribution.

scholarly journals Origin of the Particulate Organic Matter in a Monsoon-Controlled Bay in Southern China

2021 ◽  
Vol 9 (5) ◽  
pp. 541
Author(s):  
Jiacheng Li ◽  
Fajin Chen ◽  
Shuwen Zhang ◽  
Chao Huang ◽  
Chunqing Chen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Particulate Organic Matter ◽  
Southern China ◽  
Organic Carbon Content ◽  
Particulate Nitrogen ◽  
Δ13c And Δ15n ◽  
Δ13c Values ◽  
Chl A ◽  
Marine Organic Matter

In this study, the isotopic composition (δ13C and δ15N), total organic carbon content, total nitrogen content, and C/N ratios of suspended particulate organic matter (POM) in Zhanjiang Bay, which is a semi-enclosed bay with concentrated artificial activities in Southern China, were analyzed in order to investigate the seasonal variations in the principal POM sources in the monsoon region. In summer, the δ13C and δ15N values showed a weak correlation with the chlorophyll a (Chl a), suggesting that terrigenous sources were dominant. However, in winter, the particulate organic carbon and particulate nitrogen values were correlated with the Chl a in the middle bay and bay mouth. Moreover, the δ13C values showed a significant correlation with Chl a during the winter, indicating that the contribution of the in situ phytoplankton was relatively important and was affected by the monsoon in winter. Compared with the corresponding δ13C values, the δ15N values exhibited a complex spatial distribution. By using a Bayesian mixing model, in the upper bay, the source of POM was mainly from marine organic matter (49%) in summer, and almost an equilibrated contribution of all sources in winter. In the middle bay and bay mouth, the POM contribution mainly originated from marine organic matter (53%) during the winter. In contrast, the POM source was mainly soil organic matter (63%) in summer, suggesting that the POM was sourced from the runoff from the upstream basin. Our results suggest that the seasonal shifts of the source of POM should be taken into account when estimating C or N mass balance in the monsoon-controlled bay.

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