Organic carbon in suspended particulate material in the North Sea: Effect of mixing resuspended and background particles

1998 ◽  
Vol 18 (11) ◽  
pp. 1333-1345 ◽  
Author(s):  
A.J. Bale ◽  
A.W. Morris
Keyword(s):  
Organic Carbon ◽  
North Sea ◽  
Particulate Material ◽  
The North ◽  
Suspended Particulate ◽  
Suspended Particulate Material ◽  
The North Sea

scholarly journals Association of Marine Archaea with the Digestive Tracts of Two Marine Fish Species

1998 ◽  
Vol 64 (8) ◽  
pp. 2894-2898 ◽  
Author(s):  
Marc J. E. C. van der Maarel ◽  
Rebekka R. E. Artz ◽  
René Haanstra ◽  
Larry J. Forney
Keyword(s):  
Particulate Matter ◽  
North Sea ◽  
Suspended Particulate Matter ◽  
Archaeal Community ◽  
Grey Mullet ◽  
The North ◽  
Suspended Particulate ◽  
The North Sea ◽  
Group Ii ◽  
Marine Archaea

ABSTRACT Recent studies have shown that archaea which were always thought to live under strict anoxic or extreme environmental conditions are also present in cold, oxygenated seawater, soils, the digestive tract of a holothurian deep-sea-deposit feeder, and a marine sponge. In this study, we show, by using PCR-mediated screening in other marine eukaryotes, that marine archaea are also present in the digestive tracts of flounder and grey mullet, two fish species common in the North Sea, in fecal samples of flounder, and in suspended particulate matter of the North Sea water column. No marine archaea could be detected in the digestive tracts of mussels or the fecal pellets of a copepod species. The archaeal 16S ribosomal DNA clone libraries of feces of flounder and the contents of the digestive tracts of grey mullet and flounder were dominated by group II marine archaea. The marine archaeal clones derived from flounder and grey mullet digestive tracts and feces formed a distinct cluster within the group II marine archaea, with 76.7 to 89.8% similarity to previously described group II clones. Fingerprinting of the archaeal community of flounder digestive tract contents and feces by terminal restriction fragment length polymorphism of archaeal 16S rRNA genes after restriction withHhaI showed a dominant fragment at 249 bp, which is likely to be derived from group II marine archaea. Clones of marine archaea that were closely related to the fish-associated marine archaea clones were obtained from suspended particulate matter of the water column at two stations in the North Sea. Terminal restriction fragment length polymorphism fingerprinting of the archaeal community present in suspended particulate matter showed the same fragment pattern as was found for the archaeal community of the flounder digestive tract contents and feces. These data demonstrate that marine archaea are present in the digestive tracts and feces of very common marine fish. It is possible that the marine archaea associated with the digestive tracts of marine fish are liberated into the water column through the feces and subsequently contribute to the marine archaeal community of suspended particulate matter.

scholarly journals Organic carbon in surface sediments of the North Sea and Skagerrak

2020 ◽  
Author(s):  
Markus Diesing ◽  
Terje Thorsnes ◽  
Lilja Rún Bjarnadóttir
Keyword(s):  
Organic Carbon ◽  
North Sea ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Complex Nature ◽  
Accumulation Rates ◽  
The North ◽  
Continental Shelves ◽  
Shelf Sediments ◽  
The North Sea

Abstract. Continental shelf sediments are places of both rapid organic carbon turnover and accumulation, while at the same time increasingly subjected to human-induced disturbances. Recent research suggests that shelf sediments might have a role to play as a natural climate solution, e.g. by protecting the seafloor against human-induced disturbance. However, we have an incomplete understanding about the centres of organic carbon accumulation and storage on continental shelves. To better constrain the rate of accumulation and the mass of organic carbon that is stored in sediments, we developed and applied a spatial modelling framework that allows to estimate those quantities from sparse observations and predictor variables known or suspected to influence the spatial patterns of these parameters. This paper presents spatial distribution patterns of organic carbon densities and accumulation rates in the North Sea and Skagerrak. We found that organic carbon stocks and accumulation rates are highest in the Norwegian Trough, while large parts of the North Sea are characterised by low stocks and zero net-accumulation. The total stock of organic carbon that is stored in the upper 0.1 m of sediments amounted to 230.5 ± 134.5 Tg, of which approximately 26 % are stored in the Norwegian Trough. Rates of organic carbon accumulation in the Norwegian Trough are on par with those reported from nearby fjords. We provide baseline datasets that could be used in marine management, e.g. for the establishment of carbon protection zones. Additionally, we highlight the complex nature of continental shelves with zones of rapid carbon cycling and accumulation juxtaposed, which will require further detailed and spatially explicit analyses to constrain sedimentary organic carbon stocks and accumulation rates globally.

scholarly journals Turbulent Mixing due to Surface Waves Indicated by Remote Sensing of Suspended Particulate Matter and Its Implementation into Coupled Modeling of Waves, Turbulence, and Circulation

2011 ◽  
Vol 41 (4) ◽  
pp. 708-724 ◽  
Author(s):  
Andrey Pleskachevsky ◽  
Mikhail Dobrynin ◽  
Alexander V. Babanin ◽  
Heinz Günther ◽  
Emil Stanev
Keyword(s):  
Particulate Matter ◽  
Surface Waves ◽  
North Sea ◽  
Suspended Particulate Matter ◽  
Turbulent Mixing ◽  
Satellite Observations ◽  
Mean Flow ◽  
The North ◽  
Suspended Particulate ◽  
The North Sea

Abstract This paper studies the impact of the surface waves on the turbulent mixing. The satellite observations of suspended particulate matter (SPM) at the ocean surface as an indicator of turbulent quantities of the flow are used. In a water column, SPM builds a vertical profile depending on settling velocities of the particles and on vertical mixing processes; thus, SPM is a perfect marker to study the turbulent quantities of the flow. Satellite observations in the North Sea show that surface SPM concentrations, in locations of its deposition, grow rapidly and build plume-shaped, long (many kilometers) uninterrupted and consistent structures during a storm. Also, satellites reveal that SPM rapidly sinks to the seabed after the storm peak has passed and wave height decreases (i.e., in the absence of strong turbulence). The nonbreaking wave-induced turbulence has been discussed, parameterized, and implemented into an equation of evolution of turbulent kinetic energy (TKE) in the frame of mean-flow concept, which can be used in existing circulation models. The ratio between dissipated and total wave energy is used to describe the influence of wave damping on the mean flow. The numerical tests reproduce experiments in a wave tank very well and are supported by observations of SPM in the North Sea. Their results show that the motion of an individual nonbreaking wave includes turbulent fluctuations if the critical Reynolds number for wave motion is exceeded, independent of the presence of currents due to wind or tides. These fluctuations can produce high diffusivity and strongly influence mixing in the upper water layer of the ocean.

scholarly journals Organic carbon densities and accumulation rates in surface sediments of the North Sea and Skagerrak

2021 ◽  
Vol 18 (6) ◽  
pp. 2139-2160
Author(s):  
Markus Diesing ◽  
Terje Thorsnes ◽  
Lilja Rún Bjarnadóttir
Keyword(s):  
Organic Carbon ◽  
North Sea ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Anthropogenic Activity ◽  
Accumulation Rates ◽  
The North ◽  
Continental Shelves ◽  
Shelf Sediments ◽  
The North Sea

Abstract. Continental shelf sediments are places of both rapid organic carbon turnover and accumulation, while at the same time increasingly subjected to human-induced disturbances. Recent research suggests that shelf sediments might have a role to play as a natural climate solution, e.g. by storing organic carbon if left undisturbed from anthropogenic activity. However, we have an incomplete understanding about the centres of organic carbon accumulation and storage on continental shelves. To better constrain the rate of accumulation and the mass of organic carbon that is stored in sediments, we developed and applied a spatial modelling framework that allows us to estimate those quantities from sparse observations and predictor variables known or suspected to influence the spatial patterns of these parameters. This paper presents spatial distribution patterns of organic carbon densities and accumulation rates in the North Sea and Skagerrak. We found that organic carbon stocks and accumulation rates are highest in the Norwegian Trough, while large parts of the North Sea are characterised by low stocks and zero net accumulation. The total stock of organic carbon that is stored in the upper 0.1 m of sediments amounted to 230.5 ± 134.5 Tg C, of which approximately 26 % is stored in the Norwegian Trough. Rates of organic carbon accumulation in the Norwegian Trough are comparable with those reported from nearby fjords. We provide baseline datasets that could be used in marine management, e.g. for the establishment of “carbon protection zones”. Additionally, we highlight the complex nature of continental shelves with zones of rapid carbon cycling and accumulation juxtaposed, which will require further detailed and spatially explicit analyses to constrain sedimentary organic carbon stocks and accumulation rates globally.

The benthic environment of the North Sea (56° to 61°N)

1988 ◽  
Vol 68 (1) ◽  
pp. 125-141 ◽  
Author(s):  
D. Basford ◽  
A. Eleftheriou
Keyword(s):  
Trace Metals ◽  
Organic Carbon ◽  
North Sea ◽  
Large Scale ◽  
Clay Content ◽  
The North ◽  
Benthic Environment ◽  
The North Sea ◽  
Sedimentation Basins ◽  
Physical And Chemical

In an attempt to describe the physical and chemical characteristics of the sediments as an environment for the invertebrate benthos, a total of 273 stations covering the sector from 56° N to 61° N in the North Sea was sampled. The sediment samples which were collected by grab and corer were analysed for particle size (as well as silt-clay content and sorting), organic carbon, plant pigments and trace metals (Cd, Pb, Zn, Ni, Co, Cu). On a smaller scale a few stations were sampled for redox potential, pH and pesticides.Taking into account the geological history and the on-going hydrographic processes, explanations for the formation of the sedimentary provinces in the North Sea were provided. The sediments were predominantly fine to medium sand, but there was a depth-related gradient with the finer grades, organic carbon and, to a lesser extent, plant pigment being found in the deeper sedimentation basins of the Fladen Grounds and Norwegian Trench.Trace metals and pesticide contaminants associated with the finer organic and inorganic fractions were higher in the sediments of the above deeper areas as well as in the vicinity of estuaries. It could be concluded that despite the enhanced concentrations of Cd, Ni, Pb and Co, at the east of Shetland, which were due to a geochemical anomaly, there was no evidence of any important or large-scale contamination of the North Sea as a whole.

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