Dispersal, concentration and deposition of suspended matter in the North Sea

Eisma, D.; Kalf, J.

doi:10.1144/gsjgs.144.1.0161

Cited by 159 publications

(70 citation statements)

References 33 publications

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“…Due to limited ship time, the Frisian Front was sampled only in autumn 1999 with RV 'Pelagia'. The sample sites were chosen to reflect gradients in sedimentation rates (Cadée 1984, Puls et al 1997) and in organic matter supply (Eisma & Kalf 1987, Kröncke & Knust 1995. The co-ordinates and some characteristics of the sites are given in Table 1 and Fig.…”

Section: Methodsmentioning

confidence: 99%

Phospholipid fatty acid profiles at depositional and non-depositional sites in the North Sea

Stoeck¹,

Kröncke²,

Duineveld³

et al. 2002

Mar. Ecol. Prog. Ser.

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The distribution of ester-linked phospholipid fatty acid (PLFA) in sediments of 12 sampling stations located in the German Bight, Skagerrak/northern Kattegat, Frisian Front, Oyster Ground, eastern North Sea and the Dogger Bank area was studied to compare the in situ microbial community structure of depositional and non-depositional sites. A total of 36 fatty acids in the range of C 12 to C 24 were determined. They consisted of saturated, branched, monounsaturated, polyunsaturated and hydroxy fatty acids, and variation was revealed in the relative proportions (mol %) of these fatty acids. The distribution of specific fatty acids was significantly different between depositional and non-depositional sites. Additionally, we could discriminate communities of sites which are intermediate in sedimentation regime. Highest total PLFA content was found at depositional sites. The PLFA profiles of all sites were dominated by bacteria, with highest bacterial contribution to the sedimentary PLFA pool at depositional sites. A high proportion of aerobic prokaryotes (up to 40%) at depositional sites indicated the occurrence of aerobic microniches in the corresponding anoxic sediments. Bacterial groups being a component of the degradation pathways of complex macromolecules (e.g. Cytophaga and Actinomycetes) were found in significant higher abundances at depositional sites compared to the other sites. At depositional sites, sulphate-reducing bacteria (SRB) (e.g. Desulfobacter spp.) were more abundant compared to the other stations. The relative contribution of microeukaryotes to the sedimentary PLFA pool was significantly higher at depositional sites. A nutritionally limited benthic system at non-depositional sites in the offshore is indicated by a microbial community exposed to higher physiological stress than those of the organically enriched sediments of the depositional sites.

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Section: Methodsmentioning

confidence: 99%

Phospholipid fatty acid profiles at depositional and non-depositional sites in the North Sea

Stoeck¹,

Kröncke²,

Duineveld³

et al. 2002

Mar. Ecol. Prog. Ser.

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“…During the last glacial maximum the plateau was exposed and coastal sands were deposited. Younger sediments of the Holocene have not been found in this area because tidal currents prevent deposition (Eisma and Kalf, 1987). The Gullfaks hydrocarbon reservoir is situated in a depth of almost 3 km (Hovland and Judd, 1988).…”

Section: Sampling Sitesmentioning

confidence: 99%

Biogeochemical processes and microbial diversity of the Gullfaks and Tommeliten methane seeps (Northern North Sea)

et al. 2008

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Abstract. Fluid flow related seafloor structures and gas seeps were detected in the North Sea in the 1970s and 1980s by acoustic sub-bottom profiling and oil rig surveys. A variety of features like pockmarks, gas vents and authigenic carbonate cements were found to be associated with sites of oil and gas exploration, indicating a link between these surface structures and the underlying, deep hydrocarbon reservoirs. In this study we performed acoustic surveys and videographic observation at Gullfaks, Holene Trench, Tommeliten, Witch's Hole and the giant pockmarks of the UK Block 15/25, to investigate the occurrence and distribution of cold seep ecosystems in the Northern North Sea. The most active gas seep sites, i.e. Gullfaks and Tommeliten, were investigated in detail. At both sites, gas bubbles escaped continuously from small holes in the seabed to the water column, reaching the upper mixed surface layer. At Gullfaks a gas emitting, flat area of 0.1 km 2 of sandy seabed covered by filamentous sulfur-oxidizing bacteria was detected. At Tommeliten, we found a patchy distribution of small bacterial mats indicating sites of gas seepage. Below the patches the seafloor consisted of sand from which gas emissions were observed. At both sites, the anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) was the major source of sulfide. Molecular analyses targeting specific lipid biomarkers and 16S rRNA gene sequences identified an active microbial community dominated by sulfur-oxidizing and sulfate-reducing bacteria (SRB) as well as methanotrophic bacteria and archaea. Stable carbon isotope values of specific, microbial fatty acids and alcohols from both sites were highly depleted in the heavy isotope 13 C, indicating that the Correspondence to: G. Wegener (gwegener@mpi-bremen.de) microbial community incorporates methane or its metabolites. The microbial community composition of both shallow seeps shows high similarities to the deep water seeps associated with gas hydrates such as Hydrate Ridge or the Eel River basin.

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“…The main water exchange with the Atlantic Ocean (51 000 km 3 year -1 inflow and 56 700 km 3 year -1 outflow) occurs via the northern boundary, while through the Dover Strait between the Netherlands and Great Britain~4900 km 3 year -1 enter the North Sea (Eisma and Kalf, 1987). Compared with these numbers, the flow into the system via precipitation, riverine freshwater input and the Baltic Sea in the East is relatively small and sums up to 895-955 km 3 year -1 (Thomas et al, 2005;Radach and Pätsch, 2007).…”

Section: Introductionmentioning

confidence: 99%

Deciphering associations between dissolved organic molecules and bacterial communities in a pelagic marine system

et al. 2016

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Dissolved organic matter (DOM) is the main substrate and energy source for heterotrophic bacterioplankton. To understand the interactions between DOM and the bacterial community (BC), it is important to identify the key factors on both sides in detail, chemically distinct moieties in DOM and the various bacterial taxa. Next-generation sequencing facilitates the classification of millions of reads of environmental DNA and RNA amplicons and ultrahigh-resolution mass spectrometry yields up to 10 000 DOM molecular formulae in a marine water sample. Linking this detailed biological and chemical information is a crucial first step toward a mechanistic understanding of the role of microorganisms in the marine carbon cycle. In this study, we interpreted the complex microbiological and molecular information via a novel combination of multivariate statistics. We were able to reveal distinct relationships between the key factors of organic matter cycling along a latitudinal transect across the North Sea. Total BC and DOM composition were mainly driven by mixing of distinct water masses and presumably retain their respective terrigenous imprint on similar timescales on their way through the North Sea. The active microbial community, however, was rather influenced by local events and correlated with specific DOM molecular formulae indicative of compounds that are easily degradable. These trends were most pronounced on the highest resolved level, that is, operationally defined 'species', reflecting the functional diversity of microorganisms at high taxonomic resolution.

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Dispersal, concentration and deposition of suspended matter in the North Sea

Cited by 159 publications

References 33 publications

Phospholipid fatty acid profiles at depositional and non-depositional sites in the North Sea

Phospholipid fatty acid profiles at depositional and non-depositional sites in the North Sea

Biogeochemical processes and microbial diversity of the Gullfaks and Tommeliten methane seeps (Northern North Sea)

Deciphering associations between dissolved organic molecules and bacterial communities in a pelagic marine system

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