scholarly journals <I>nirS</I>-containing denitrifier communities in the water column and sediment of the Baltic Sea

2007 ◽  
Vol 4 (3) ◽  
pp. 255-268 ◽  
Author(s):  
S. Falk ◽  
M. Hannig ◽  
C. Gliesche ◽  
R. Wardenga ◽  
M. Köster ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Baltic Sea ◽  
Water Column ◽  
Community Composition ◽  
Environmental Gradients ◽  
Marker Gene ◽  
The Baltic Sea ◽  
Marine Habitats ◽  
The Baltic ◽  
Denitrifier Communities

Abstract. The aim of this study was to compare structural differences in the nirS-type denitrifying microbial communities along the environmental gradients observed in the water column and coastal sediments of the Baltic Sea. To link community structure and environmental gradients, denitrifier communities were analyzed by terminal restriction fragment length polymorphism (T-RFLP) based on nirS as a functional marker gene for denitrification. nirS-type denitrifier community composition was further evaluated by phylogenetic analysis of nirS sequences from clone libraries. T-RFLP analysis indicated some overlap but also major differences between communities from the water column and the sediment. Shifts in community composition along the biogeochemical gradients were observed only in the water column while denitrifier communities were rather uniform within the upper 30 mm of the sediment. Specific terminal restriction fragments (T-RFs) indicative of the sulfidic zone suggest the presence of nitrate-reducing and sulfide-oxidizing microorganisms that were previously shown to be important at the suboxic-sulfidic interface in the water column of the Baltic Sea. Phylogenetic analysis of nirS genes from the Baltic Sea and of sequences from marine habitats all over the world indicated distinct denitrifier communities that grouped mostly according to their habitats. We suggest that these subgroups of denitrifiers had developed after selection through several factors, i.e. their habitats (water column or sediment), impact by prevalent environmental conditions and isolation by large geographic distances between habitats.

scholarly journals <i>NirS</i>-containing denitrifier communities in the water column and sediment of the Baltic Sea

2006 ◽  
Vol 3 (3) ◽  
pp. 697-727 ◽  
Author(s):  
S. Falk ◽  
M. Hannig ◽  
G. Braker ◽  
R. Wardenga ◽  
M. Köster ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Baltic Sea ◽  
Water Column ◽  
Community Composition ◽  
Environmental Gradients ◽  
Marker Gene ◽  
The Baltic Sea ◽  
Marine Habitats ◽  
The Baltic ◽  
Denitrifier Communities

Abstract. The aim of this study was to compare structural differences in the denitrifying microbial communities along the environmental gradients observed in the water column and coastal sediments of the Baltic Sea. To link community structure and environmental gradients, denitrifier communities were analyzed by terminal restriction fragment length polymorphism (T-RFLP) based on nirS as a functional marker gene for denitrification. NirS-type denitrifier community composition was further evaluated by phylogenetic analysis of nirS sequences from clone libraries. T-RFLP analysis indicated some overlap but also major differences of communities from the water column and the sediment. Shifts in community composition along the biogeochemical gradients were observed only in the water column while denitrifier communities were rather uniform within the upper 30 mm of the sediment. Specific terminal restriction fragments (T-RFs) indicative for the sulfidic zone suggest the presence of nitrate-reducing and sulfide-oxidizing microorganisms that were previously shown to be important at the suboxic-sulfidic interface in the water column of the Baltic Sea. Phylogenetic analysis of nirS genes from the Baltic Sea and of sequences from marine habitats all over the world indicated distinct denitrifier communities that grouped mostly according to their habitat. We suggest that these subgroups of denitrifiers had developed after selection through several factors, i.e. their habitats (water column or sediment), impact by prevalent environmental conditions and isolation by large geographic distances between habitats.

scholarly journals Bacteriohopanepolyols record stratification, nitrogen fixation and other biogeochemical perturbations in Holocene sediments of the central Baltic Sea

2013 ◽  
Vol 10 (4) ◽  
pp. 2725-2735 ◽  
Author(s):  
M. Blumenberg ◽  
C. Berndmeyer ◽  
M. Moros ◽  
M. Muschalla ◽  
O. Schmale ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Water Column ◽  
Stable Stratification ◽  
The Baltic Sea ◽  
Allochthonous Input ◽  
The North ◽  
Water Column Stratification ◽  
Gotland Deep ◽  
History Of ◽  
The Baltic

Abstract. The Baltic Sea, one of the world's largest brackish-marine basins, established after deglaciation of Scandinavia about 17 000 to 15 000 yr ago. In the changeable history of the Baltic Sea, the initial freshwater system was connected to the North Sea about 8000 yr ago and the modern brackish-marine setting (Littorina Sea) was established. Today, a relatively stable stratification has developed in the water column of the deep basins due to salinity differences. Stratification is only occasionally interrupted by mixing events, and it controls nutrient availability and growth of specifically adapted microorganisms and algae. We studied bacteriohopanepolyols (BHPs), lipids of specific bacterial groups, in a sediment core from the central Baltic Sea (Gotland Deep) and found considerable differences between the distinct stages of the Baltic Sea's history. Some individual BHP structures indicate contributions from as yet unknown redoxcline-specific bacteria (bacteriohopanetetrol isomer), methanotrophic bacteria (35-aminobacteriohopanetetrol), cyanobacteria (bacteriohopanetetrol cyclitol ether isomer) and from soil bacteria (adenosylhopane) through allochthonous input after the Littorina transgression, whereas the origin of other BHPs in the core has still to be identified. Notably high BHP abundances were observed in the deposits of the brackish-marine Littorina phase, particularly in laminated sediment layers. Because these sediments record periods of stable water column stratification, bacteria specifically adapted to these conditions may account for the high portions of BHPs. An additional and/or accompanying source may be nitrogen-fixing (cyano)bacteria, which is indicated by a positive correlation of BHP abundances with Corg and δ15N.

scholarly journals Development of marine landscape maps for the Baltic Sea and the Kattegat using geophysical and hydrographical parameters

2007 ◽  
Vol 13 ◽  
pp. 61-64 ◽  
Author(s):  
Zyad K. Al-Hamdani ◽  
Johnny Reker ◽  
Jørgen O. Leth ◽  
Anu Reijonen ◽  
Aarno T. Kotilainen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Marine Environment ◽  
Leisure Activities ◽  
Biological Information ◽  
Marine Biodiversity ◽  
The European Union ◽  
The Baltic Sea ◽  
Marine Habitats ◽  
The Baltic ◽  
Bothnian Bay

The Baltic Sea is one of the largest brackish water bodies in the world (Segerstråle 1957) with a number of basins varying from almost fresh water in the northern part of the Bothnian Bay via the more brackish conditions in the southern part to the saline waters of the Kattegat. The Baltic Sea is subject to severe environmental degradation caused by commercial and leisure activities, including fisheries, dredging, tourism, coas t a l development and land-based pollution sources. This causes severe pressures on vulnerable marine habitats and natural re- sources, and a tool for aiding marine management is therefore strongly needed. The marine landscape concept presented by Roff &Taylor (2000) is based on the use of available broad-scale geological, physical and hydrographical data to prepare ecologically meaningful maps for areas with little or no biological information. The concept, which was elaborated by Day & Roff (2000) was applied in UK waters (Connor et al. 2006) before it was adopted by the BALANCE project described here. The aim of developing marine landscape maps is to characterise the marine environment of the Baltic Sea region (the Baltic Sea together with the Kattegat) using geophysical and hydrographical parameters. Such maps can be applied, for example, to an assessment of the Baltic-wide network of marine protected areas, and thus provide a sustainable ecosystem-based approach to the protection of the marine environment from human activities, and contribute to the conservation of marine biodiversity. The BALANCE project is based on transnational and cross-sectoral co-operation with participants from nine countries surrounding the Baltic Sea as well as Norway (Fig. 1), and is partially financed by the European Union through the BSR INTERREG IIIB programme.

scholarly journals Hypoxia and nitrogen processing in the Baltic Sea water column

2012 ◽  
Vol 57 (1) ◽  
pp. 325-337 ◽  
Author(s):  
Susanna Hietanen ◽  
Helena Jäntti ◽  
Christo Buizert ◽  
Klaus Jürgens ◽  
Matthias Labrenz ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Water Column ◽  
Sea Water ◽  
The Baltic Sea ◽  
The Baltic

scholarly journals Evolution at two time-frames: ancient and common origin of two structural variants involved in local adaptation of the European plaice (Pleuronectes platessa)

2019 ◽  
Author(s):  
Alan Le Moan ◽  
Dorte Bekkevold ◽  
Jakob Hemmer-Hansen
Keyword(s):  
Population Structure ◽  
Baltic Sea ◽  
Allele Frequency ◽  
Environmental Gradients ◽  
Common Origin ◽  
The Baltic Sea ◽  
Pleuronectes Platessa ◽  
The North ◽  
The Baltic ◽  
Time Frames

AbstractChanging environmental conditions can lead to population diversification through differential selection on standing genetic variation. Structural variant (SV) polymorphisms provide examples of ancient alleles that in time become associated with novel environmental gradients. The European plaice (Pleuronectes platessa) is a marine flatfish showing large allele frequency differences at two putative SVs associated with environmental variation. In this study, we explored the contribution of these SVs to population structure across the North East Atlantic. We compared genome wide population structure using sets of RAD sequencing SNPs with the spatial structure of the SVs. We found that in contrast to the rest of the genome, the SVs were only weakly associated with an isolation-by-distance pattern. Indeed, both SVs showed important allele frequency differences associated with two different environmental gradients, with the same allele increasing both along the salinity gradient of the Baltic Sea, and the latitudinal gradient along the Norwegian coast. Nevertheless, both SVs were found to be polymorphic across most sampling sites, even in the Icelandic population inferred to originate from a different glacial refuge than the remaining populations from the European continental shelf. Phylogenetic analyses suggested that the SV alleles are much older than the age of the Baltic Sea itself. These results suggest that the SVs are older than the age of the environmental gradients with which they currently co-vary. Interestingly, both SVs shared similar phylogenetic and genetic diversity, suggesting that they have a common origin. Altogether, our results suggest that the plaice SVs were shaped by evolutionary processes occurring at two time-frames, firstly following their common origin and secondly related to their current association with more recent environmental gradients such as those found in the North Sea − Baltic Sea transition zone.

Tracking the spatiotemporal variability of the oxic–anoxic interface in the Baltic Sea with broadband acoustics

2020 ◽  
Author(s):  
Elizabeth Weidner ◽  
Christian Stranne ◽  
Jonas Hentati Sundberg ◽  
Thomas C Weber ◽  
Larry Mayer ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Baltic Sea ◽  
Water Column ◽  
Acoustic Scattering ◽  
Spatiotemporal Variability ◽  
Coastal Zones ◽  
Anoxic Zone ◽  
The Baltic Sea ◽  
Impedance Contrast ◽  
The Baltic

Abstract Anoxic zones, regions of the water column completely devoid of dissolved oxygen, occur in open oceans and coastal zones worldwide. The Baltic Sea is characterized by strong salinity-driven stratification, maintained by occasional water inflows from the Danish Straights and freshwater input from rivers. Between inflow events, the stratification interface between surface and deep waters hinders mixing and ventilation of deep water; consequently, the bottom waters of large regions of the Baltic are anoxic. The onset of the anoxic zone is closely coincident with the depth of the halocline and, as a result, the interface between oxic and anoxic waters corresponds to a strong impedance contrast. Here, we track acoustic scattering from the impedance contrast utilizing a broadband split-beam echosounder in the Western Gotland Basin and link it to a dissolved oxygen level of 2 ml/l using ground truth stations. The broadband acoustic dataset provides the means to remotely observe the spatiotemporal variations in the oxic–anoxic interface, map out the extent of the anoxic zone with high resolution, and identify several mechanisms influencing the vertical distribution of oxygen in the water column. The method described here can be used to study other systems with applications in ongoing oceanographic monitoring programs.

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