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

2012 ◽  
Vol 9 (12) ◽  
pp. 17139-17165
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 developed in the water column of the deep basins due to salinity differences. Stratification is only occasionally interrupted by mixing events, and 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. Individual BHP structures indicate contributions from as yet unknown redoxcline-specific bacteria (bacteriohopanetetrol isomer), methanotrophic bacteria (35-aminobacteriohopanetetrol), cyanobacteria (bacteriohopanetetrol cyclitol ether isomer) and, through allochthonous input after the Littorina transgression, from soil bacteria (adenosylhopane), 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 good correlation of BHP abundances with Corg and δ15N.

scholarly journals Are recent changes in sediment manganese sequestration in the euxinic basins of the Baltic Sea linked to the expansion of hypoxia?

2015 ◽  
Vol 12 (16) ◽  
pp. 4875-4894 ◽  
Author(s):  
C. Lenz ◽  
T. Jilbert ◽  
D.J. Conley ◽  
M. Wolthers ◽  
C.P. Slomp
Keyword(s):  
Baltic Sea ◽  
Water Column ◽  
North Sea ◽  
The Baltic Sea ◽  
The Past ◽  
Gotland Deep ◽  
Carbonate Formation ◽  
The Baltic ◽  
Mn Oxides ◽  
Deep Area

Abstract. Expanding hypoxia in the Baltic Sea over the past century has led to the development of anoxic and sulfidic (euxinic) deep basins that are only periodically ventilated by inflows of oxygenated waters from the North Sea. In this study, we investigate the potential consequences of the expanding hypoxia for manganese (Mn) burial in the Baltic Sea using a combination of pore water and sediment analyses of dated sediment cores from eight locations. Diffusive fluxes of dissolved Mn from sediments to overlying waters at oxic, hypoxic and euxinic sites are consistent with an active release of Mn from these areas. Although the present-day fluxes are significant (ranging up to ca. 240 μmol m−2 d−1), comparison to published water column data suggests that the current benthic release of Mn is small when compared to the large pool of Mn already present in the hypoxic and anoxic water column. Our results highlight two modes of Mn carbonate formation in sediments of the deep basins. In the Gotland Deep area, Mn carbonates likely form from Mn oxides that are precipitated from the water column directly following North Sea inflows. In the Landsort Deep, in contrast, Mn carbonate and Mn sulfide layers appear to form independently of inflow events, and are possibly related to the much larger and continuous input of Mn oxides linked to sediment focusing. Whereas Mn-enriched sediments continue to accumulate in the Landsort Deep, this does not hold for the Gotland Deep area. Here, a recent increase in euxinia, as evident from measured bottom water sulfide concentrations and elevated sediment molybdenum (Mo), coincides with a decline in sediment Mn content. Sediment analyses also reveal that recent inflows of oxygenated water (since ca. 1995) are no longer consistently recorded as Mn carbonate layers. Our data suggest that eutrophication has not only led to a recent rise in sulfate reduction rates but also to a decline in reactive Fe input to these basins. We hypothesize that these factors have jointly led to higher sulfide availability near the sediment–water interface after inflow events. As a consequence, the Mn oxides may be reductively dissolved more rapidly than in the past and Mn carbonates may no longer form. Using a simple diagenetic model for Mn dynamics in the surface sediment, we demonstrate that an enhancement of the rate of reduction of Mn oxides is consistent with such a scenario. Our results have important implications for the use of Mn carbonate enrichments as a redox proxy in marine systems.

Holocene history of the Baltic Sea as recorded in a sediment core from the Gotland Deep

1996 ◽  
Vol 134 (3-4) ◽  
pp. 183-201 ◽  
Author(s):  
G. Sohlenius ◽  
J. Sternbeck ◽  
E. Andrén ◽  
P. Westman
Keyword(s):  
Baltic Sea ◽  
Sediment Core ◽  
The Baltic Sea ◽  
Gotland Deep ◽  
History Of ◽  
The Baltic

Nutrient regeneration and benthic fluxes in the Coastal Baltic and North Sea

2020 ◽  
Author(s):  
Kirstin Dähnke ◽  
Andreas Neumann ◽  
Tina Sanders
Keyword(s):  
Stable Isotope ◽  
Baltic Sea ◽  
Water Column ◽  
North Sea ◽  
Surface Sediments ◽  
Nutrient Regeneration ◽  
The Baltic Sea ◽  
The North ◽  
The North Sea ◽  
The Baltic

<p>Sediments in the coastal ocean can play an important role in nutrient regeneration and in recharging the water column with dissolved inorganic nutrients. This function, however, depends on various variables, such as physical characteristics, but also on biological traits like fauna composition and activity. To unravel and quantify these effects, we investigated nutrient fluxes and nitrate stable isotope composition in water samples along a North Sea – Skagerrak – Baltic Sea gradient during the Maria S. Merian cruise MSM 50 in January 2016.</p><p>Especially in the North Sea and the Skagerrak region, d<sup>15</sup>N values of nitrate were unexpectedly high, suggesting that underlying sediments with relatively enriched isotope signatures were a source of nitrate. This nitrification signal, however, resembled an autumn situation rather than the expected winter values. Parallel sediment incubations confirm that the benthic rates of oxygen consumption and nutrient turnover were indeed very similar to respective rates in autumn and that the sediment was a source of recycled nitrate. From the North Sea towards the Baltic Sea, we found, in accordance with previous studies, a depletion in nitrate stable isotope values. This is indicative of different nitrate sources in the respective basins: in the North Sea region, N of anthropogenic origin leads to high N values in surface sediments and in newly generated nitrate. Due to a higher share of nitrogen fixation, the nitrogen stable isotope signal of surface sediments in the Baltic Sea was depleted, which in turn was mirrored in lower nitrate isotope values in the water column above the sediment.</p><p>Overall, the data highlight the importance of nitrate regeneration. Parallel flux measurements reveal that faunal activity shifts the nutrient balance from sequestration to regeneration. Seasonal differences enable us to unravel seasonal effects of fauna and microbiota on nutrient budgets.</p>

scholarly journals Are recent changes in sediment manganese sequestration in the euxinic basins of the Baltic Sea linked to the expansion of hypoxia?

2014 ◽  
Vol 11 (6) ◽  
pp. 9889-9918
Author(s):  
C. Lenz ◽  
T. Jilbert ◽  
D. J. Conley ◽  
M. Wolthers ◽  
C. P. Slomp
Keyword(s):  
Baltic Sea ◽  
Water Column ◽  
Pore Water ◽  
North Sea ◽  
The Baltic Sea ◽  
Gotland Deep ◽  
Carbonate Formation ◽  
The Baltic ◽  
Mn Oxides ◽  
Deep Area

Abstract. Expanding hypoxia in the Baltic Sea over the past century has led to anoxic and sulfidic (euxinic) deep basins that are only periodically ventilated by inflows of oxygenated waters from the North Sea. In this study, we investigate the consequences of the expanding hypoxia for manganese (Mn) burial in the Baltic Sea using a combination of pore water and sediment analyses of well-dated sediment cores from 8 locations. Diffusive fluxes of dissolved Mn from sediments to overlying waters at oxic and hypoxic sites are in line with an active release of Mn from these areas. However, this flux of Mn is only small when compared to the large pool of Mn already present in the hypoxic and anoxic water column. Our results highlight two modes of Mn carbonate formation in sediments of the deep basins. In the Gotland Deep area, Mn carbonates likely form from Mn oxides that are precipitated from the water column directly following North Sea inflows. In the Landsort Deep, in contrast, Mn carbonate and Mn sulfide layers form independent of inflow events, with pore water Mn produced in deeper layers of the sediment acting as a key Mn source. While formation of Mn enrichments in the Landsort Deep continues to the present, this does not hold for the Gotland Deep area. Here, increased euxinia, as evident from measured bottom water sulfide concentrations and elevated sediment molybdenum (Mo), goes hand in hand with a decline in sediment Mn and recent inflows of oxygenated water (since ca. 1995) are no longer consistently recorded as Mn carbonate layers. We postulate that the reduction of Mn oxides by hydrogen sulfide following inflows has become so rapid that Mn2+ is released to the water column before Mn carbonates can form. Our results have important implications for the use of Mn carbonate enrichments as a redox proxy in marine systems.

Russian Oil: Production and Exports

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto
Keyword(s):  
Baltic Sea ◽  
Statistical Data ◽  
Oil Production ◽  
The Baltic Sea ◽  
North West ◽  
The North ◽  
Oil Transportation ◽  
Sea Ports ◽  
The Baltic

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.

Paleoecological study of bottom sediments of the lake Goluboye (Karelian Isthmus) according to the results of diatom analysis

2019 ◽  
pp. 265-269
Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Bottom Sediments ◽  
Modern Science ◽  
Karelian Isthmus ◽  
The Baltic Sea ◽  
Diatom Analysis ◽  
North West ◽  
The North ◽  
Important Direction ◽  
The Baltic

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.

Contacts and Networks in the Baltic Sea Region

2019 ◽  
Keyword(s):  
Baltic Sea ◽  
Final Section ◽  
Religious Studies ◽  
The Baltic Sea ◽  
Cultural Goods ◽  
The Third ◽  
Baltic Sea Region ◽  
The World ◽  
History Of ◽  
The Baltic

Since prehistoric times, the Baltic Sea has functioned as a northern mare nostrum — a crucial nexus that has shaped the languages, folklore, religions, literature, technology, and identities of the Germanic, Finnic, Sámi, Baltic, and Slavic peoples. This anthology explores the networks among those peoples. The contributions to Contacts and Networks in the Baltic Sea Region: Austmarr as a Northern mare nostrum, ca. 500-1500 ad address different aspects of cultural contacts around and across the Baltic from the perspectives of history, archaeology, linguistics, literary studies, religious studies, and folklore. The introduction offers a general overview of crosscultural contacts in the Baltic Sea region as a framework for contextualizing the volume’s twelve chapters, organized in four sections. The first section concerns geographical conceptions as revealed in Old Norse and in classical texts through place names, terms of direction, and geographical descriptions. The second section discusses the movement of cultural goods and persons in connection with elite mobility, the slave trade, and rune-carving practice. The third section turns to the history of language contacts and influences, using examples of Finnic names in runic inscriptions and Low German loanwords in Finnish. The final section analyzes intercultural connections related to mythology and religion spanning Baltic, Finnic, Germanic, and Sámi cultures. Together these diverse articles present a dynamic picture of this distinctive part of the world.

The History of Cyanobacterial Blooms in the Baltic Sea

AMBIO ◽  
2001 ◽  
Vol 30 (4) ◽  
pp. 172-178 ◽  
Author(s):  
Terttu Finni ◽  
Kaisa Kononen ◽  
Riitta Olsonen ◽  
Kerstin Wallström
Keyword(s):  
Baltic Sea ◽  
Cyanobacterial Blooms ◽  
The Baltic Sea ◽  
History Of ◽  
The Baltic

scholarly journals The carbon budget of the Baltic Sea

2011 ◽  
Vol 8 (11) ◽  
pp. 3219-3230 ◽  
Author(s):  
K. Kuliński ◽  
J. Pempkowiak
Keyword(s):  
Organic Carbon ◽  
Baltic Sea ◽  
Carbon Budget ◽  
The Other ◽  
Minor Importance ◽  
The Baltic Sea ◽  
Sources And Sinks ◽  
The North ◽  
The North Sea ◽  
The Baltic

Abstract. This paper presents the results of a comprehensive study of the Baltic Sea carbon budget. The Baltic Sea is very much influenced by terrestrial carbon input. Rivers are the largest carbon source, and their input amounts to 10.90 Tg C yr−1 (Tg = 1012 g) with a 37.5% contribution of organic carbon. On the other hand, carbon is effectively exported from the Baltic to the North Sea (7.67 Tg C yr−1) and is also buried in bottom sediments (2.73 Tg C yr−1). The other sources and sinks of carbon are of minor importance. The net CO2 emission (1.05 Tg C yr−1) from the Baltic to the atmosphere was calculated as the closing term of the carbon budget presented here. There is a net loss of organic carbon, which indicates that the Baltic Sea is heterotrophic.

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