Organic carbon and bacterial heterotrophic activity in the maximum turbidity zone of the Seine estuary (France)

2006 ◽  
Vol 68 (1) ◽  
pp. 78-85
Author(s):  
Pierre Servais ◽  
Josette Garnier
Keyword(s):  
Organic Carbon ◽  
Seine Estuary ◽  
Heterotrophic Activity ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity

scholarly journals Controls on soil organic carbon stocks in tidal marshes along an estuarine salinity gradient

2016 ◽  
Vol 13 (24) ◽  
pp. 6611-6624 ◽  
Author(s):  
Marijn Van de Broek ◽  
Stijn Temmerman ◽  
Roel Merckx ◽  
Gerard Govers
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Salt Marshes ◽  
Salinity Gradient ◽  
Tidal Marshes ◽  
Freshwater Marshes ◽  
Marsh Sediments ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity ◽  
Soc Stocks

Abstract. Tidal marshes are sedimentary environments and are among the most productive ecosystems on Earth. As a consequence they have the potential to reduce atmospheric greenhouse gas concentrations by sequestering organic carbon (OC). In the past decades, most research on soil organic carbon (SOC) storage in marsh environments has focused on salt marshes, leaving carbon dynamics in brackish and freshwater marshes largely understudied and neglecting the diversity among tidal marshes. We therefore conducted an extensive sampling campaign to quantify and characterize SOC stock in marshes along a salinity gradient in the Scheldt estuary (Belgium and the Netherlands). We find that SOC stocks vary significantly along the estuary, from 46 in freshwater marshes to 10 kg OC m−2 in salt marshes. Our data also show that most existing studies underestimate total SOC stocks due to shallow soil sampling, which also influences reported patterns in OC storage along estuaries. In all sampled tidal marsh sediments the SOC concentration is more or less constant from a certain depth downward. However, this concentration decreases with increasing salinity, indicating that the amount of stable SOC decreases from the upper estuary towards the coast. Although the net primary production of macrophytes differs along the estuary, our data suggest that the differences in OC storage are caused mainly by variations in suspended sediment concentration and stable particulate OC (POC) content in the water along the estuary. The fraction of terrestrial suspended sediments and POC that is transported downstream of the maximum turbidity zone is very limited, contributing to smaller amounts of long-term OC sequestration in brackish and salt marsh sediments. In addition, high rates of sediment deposition on freshwater tidal marshes in the maximum turbidity zone promote efficient burial of OC in these marsh sediments.

scholarly journals Oxic/anoxic oscillations and organic carbon mineralization in an estuarine maximum turbidity zone (The Gironde, France)

1999 ◽  
Vol 44 (5) ◽  
pp. 1304-1315 ◽  
Author(s):  
GwenaËl Abril ◽  
Henri Etcheber ◽  
Pierre Le Hir ◽  
Philippe Bassoullet ◽  
Bernard Boutier ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Mineralization ◽  
Organic Carbon Mineralization ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity

scholarly journals The importance of an estuarine salinity gradient on soil organic carbon stocks of tidal marshes

2016 ◽  
Author(s):  
Marijn Van de Broek ◽  
Stijn Temmerman ◽  
Roel Merckx ◽  
Gerard Govers
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Salt Marshes ◽  
Net Primary Production ◽  
Salinity Gradient ◽  
Tidal Marshes ◽  
Freshwater Marshes ◽  
Marsh Sediments ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity

Abstract. Tidal marshes are sedimentary environments that are among the most productive ecosystems on earth. As a consequence tidal marshes, and vegetated coastal ecosystems in general, have the potential to reduce atmospheric greenhouse gas concentrations as they efficiently sequester soil organic carbon (SOC). In the past decades, most research has focused on salt marshes, leaving carbon dynamics in brackish- and freshwater marshes largely understudied and neglecting the diversity among tidal marshes. Moreover, most existing studies underestimate total organic carbon (OC) stocks due to shallow soil sampling, which also influences reported patterns in OC storage along estuaries. We find that SOC stocks vary significantly along the salinity gradient of a temperate estuary (Scheldt estuary, Belgium and The Netherlands), from 46 kg OC m−2 in freshwater marshes to 10 kg OC m−2 in saltmarshes. In all tidal marsh sediments the OC concentration has a constant value from a certain depth below the surface downward. However, this concentration decreases with increasing salinity, indicating that the amount of stabile SOC decreases from the upper estuary towards the coast. Although net primary production of macrophytes differs along the estuary, our data suggest that these differences in OC storage are caused mainly by variations in suspended sediment concentration and stable particulate OC (POC) content in the water along the estuary. The fraction of suspended sediments and POC that is transported downstream the maximum turbidity zone is very limited, contributing to smaller amounts of long term OC sequestration in brackish- and saltmarsh sediments. In addition, high rates of sediment deposition on freshwater tidal marshes in the maximum turbidity zone promote efficient burial of OC in these marsh sediments.

Life Under Exceptional Conditions—Isotopic Niches of Benthic Invertebrates in the Estuarine Maximum Turbidity Zone

2016 ◽  
Vol 40 (2) ◽  
pp. 502-512 ◽  
Author(s):  
Thomas Taupp ◽  
Claudia Hellmann ◽  
René Gergs ◽  
Carola Winkelmann ◽  
Markus A. Wetzel
Keyword(s):  
Benthic Invertebrates ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity

Bacterial and phytoplankton production in the maximum turbidity zone of three European estuaries: the Elbe, Westerschelde and Gironde

1999 ◽  
Vol 22 (2-3) ◽  
pp. 151-171 ◽  
Author(s):  
Nico K Goosen ◽  
Jacco Kromkamp ◽  
Jan Peene ◽  
Pieter van Rijswijk ◽  
Peter van Breugel
Keyword(s):  
Phytoplankton Production ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity ◽  
European Estuaries

scholarly journals Dynamic Model and Numerical Simulation of Maximum Turbidity Zone Formation in River Inlet

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Huawei Xie ◽  
Shubham Sharma ◽  
Milad Sadeghzadeh ◽  
Alibek Issakhov
Keyword(s):  
Numerical Simulation ◽  
Dynamic Model ◽  
Salt Water ◽  
Transitional Zone ◽  
Reynolds Stress Model ◽  
Natural Habitats ◽  
Zone Formation ◽  
Maximum Turbidity Zone ◽  
Maximum Turbidity

The estuary of a river can be seen as a relatively free and partially closed coastal body. It is connected to the ocean and is a transitional zone of rivers, which contains processes from land to sea and from fresh water to salt water. The estuary is one of the most productive natural habitats in the world and carries a large number of sediments due to natural factors such as changes in runoff and tides. Therefore, many coastal areas with river estuaries have become the most densely populated areas in the human population. In this paper, the RSM (Reynolds stress model) turbulence model and the PID (proportional integral derivative) algorithm are successfully used to simulate the dynamic model and for the numerical simulation of the formation of turbidity maximum zone in the estuary, which provides a theoretical basis for the follow-up of the similar research studies.

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