scholarly journals The foraminiferal record in the Holocene evolution of the Mecklenburg Bay (south-western Baltic Sea)

2021 ◽  
Vol 50 (2) ◽  
pp. 169-183
Author(s):  
Robert Kostecki ◽  
Teresa Radziejewska
Keyword(s):  
Baltic Sea ◽  
Environmental Changes ◽  
Thick Layer ◽  
Sediment Geochemistry ◽  
Foraminiferal Assemblage ◽  
The Holocene ◽  
The Core ◽  
Dominance Structure ◽  
Foraminiferal Record ◽  
Group Species

Abstract Foraminiferal assemblages were analyzed in a 620-cm long core retrieved from the central part of the Mecklenburg Bay (MB, south-western Baltic Sea) to aid in the reconstruction of environmental changes occurring in the area during the Holocene and to complement a set of previously investigated palaeoenvironmental proxies. A total of five foraminifera-based stratigraphic units were identified, including an initial 80-cm thick layer devoid of foraminifera. The next two units featured an increasing abundance of the foraminiferal assemblage dominated by the calcareous Ammonia group species. Nearly all the calcareous foraminifera found in the core were decalcified. Following the maximum abundance within the 470–410 cm layer, the foraminiferal abundance declined sharply and the assemblage’s dominance structure changed to domination of the agglutinated foraminiferal species, Eggerelloides scaber, which continued up to the top of the core and marked a pronounced shift in environmental conditions (shallower depth, lower salinity, more dynamic sedimentation conditions). The foraminifera-based stratigraphy of the core proved to be complementary to that emerging from previous analyses of diatoms and sediment geochemistry.

scholarly journals Rapid environmental responses to climate-induced hydrographic changes in the Baltic Sea entrance

2019 ◽  
Vol 16 (19) ◽  
pp. 3835-3852 ◽  
Author(s):  
Laurie M. Charrieau ◽  
Karl Ljung ◽  
Frederik Schenk ◽  
Ute Daewel ◽  
Emma Kritzberg ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Baltic Sea ◽  
Oxygen Concentration ◽  
Environmental Conditions ◽  
Nutrient Loading ◽  
Environmental Changes ◽  
Organic Matter Content ◽  
Sediment Geochemistry ◽  
Dissolved Oxygen Concentration ◽  
Foraminiferal Assemblage

Abstract. The Öresund (the Sound), which is a part of the Danish straits, is linking the marine North Sea and the brackish Baltic Sea. It is a transition zone where ecosystems are subjected to large gradients in terms of salinity, temperature, carbonate chemistry, and dissolved oxygen concentration. In addition to the highly variable environmental conditions, the area is responding to anthropogenic disturbances in, e.g., nutrient loading, temperature, and pH. We have reconstructed environmental changes in the Öresund during the last ca. 200 years, and especially dissolved oxygen concentration, salinity, organic matter content, and pollution levels, using benthic foraminifera and sediment geochemistry. Five zones with characteristic foraminiferal assemblages were identified, each reflecting the environmental conditions for the respective period. The largest changes occurred around 1950, when the foraminiferal assemblage shifted from a low diversity fauna dominated by the species Stainforthia fusiformis to higher diversity and abundance and dominance of the Elphidium species. Concurrently, the grain-size distribution shifted from clayey to sandier sediment. To explore the causes of the environmental changes, we used time series of reconstructed wind conditions coupled with large-scale climate variations as recorded by the North Atlantic Oscillation (NAO) index as well as the ECOSMO II model of currents in the Öresund area. The results indicate increased changes in the water circulation towards stronger currents in the area after the 1950s. The foraminiferal fauna responded quickly (<10 years) to the environmental changes. Notably, when the wind conditions, and thereby the current system, returned in the 1980s to the previous pattern, the foraminiferal assemblage did not rebound. Instead, the foraminiferal faunas displayed a new equilibrium state.

Geological, Paleoclimatological, and Archaeological History of the Baltic Sea Region Since the Last Glaciation

2020 ◽  
Author(s):  
Jan Harff ◽  
Hauke Jöns ◽  
Alar Rosentau
Keyword(s):  
Baltic Sea ◽  
Sea Level Rise ◽  
Sea Level ◽  
Little Ice Age ◽  
Environmental Changes ◽  
Ice Age ◽  
The Baltic Sea ◽  
The Holocene ◽  
Socioeconomic System ◽  
The Baltic

The correlation of climate variability; the change environment, in particular the change of coastlines; and the development of human societies during the last millennia can be studied exemplarily in the Baltic area. The retreat of the Scandinavian ice-sheet vertical crustal movement (glacio-isostatic adjustment), together with climatically controlled sea-level rise and a continuously warming atmosphere, determine a dramatic competition between different forcings of the environment that advancing humans are occupying step by step after the glaciation. These spatially and temporally changing life conditions require a stepwise adjustment of survival strategies. Changes in the natural environment can be reconstructed from sedimentary, biological proxy data and archaeological information. According to these reconstructions, the main shift in the Baltic area’s environment happened about 8,500 years before present (BP) when the Baltic Sea became permanently connected to the Atlantic Ocean via the Danish straits and the Sound, and changed the environment from lacustrine to brackish-marine conditions. Human reaction to environmental changes in prehistoric times is mainly reconstructed from remains of ancient settlements—onshore in the uplifting North and underwater in the South dominated by sea-level rise. According to the available data, the human response to environmental change was mainly passive before the successful establishment of agriculture. But it became increasingly active after people settled down and the socioeconomic system changed from hunter-gatherer to farming communities. This change, mainly triggered by the climatic change from the Holocene cool phase to the warming period, is clearly visible in Baltic basin sediment cores as a regime shift 6,000 years (BP). But the archaeological findings prove that the relatively abrupt environmental shift is reflected in the socioeconomic system by a period of transition when hunter-gatherer and farming societies lived in parallel for several centuries. After the Holocene warming, the permanent regression in the Northern Baltic Sea and the transgression in the South did affect the socioeconomic response of the Baltic coastal societies, who migrated downslope at the regressive coast and upslope at the transgressive coast. The following cooling phases, in particular the Late Antique Little Ice Age (LALIA) and the Little Ice Age (LIA), are directly connected with migration and severe changes of the socioeconomic system. After millennia of passive reaction to climate and environmental changes, the Industrial Revolution finally enabled humans to influence and protect actively the environment, and in particular the Baltic Sea shore, by coastal constructions. On the other hand, this ability also affected climate and environment negatively because of the disturbance of the natural balance between climate, geosystem, and ecosystem.

scholarly journals Sediment geochemistry studies in the Gulf of Finland and the Baltic Sea : a retrospective view

Baltica ◽  
2016 ◽  
Vol 29 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Henry Vallius
Keyword(s):  
Baltic Sea ◽  
Environmental Changes ◽  
Great Part ◽  
Sediment Geochemistry ◽  
Gulf Of Finland ◽  
The Baltic Sea ◽  
Retrospective View ◽  
Research Programmes ◽  
The Baltic ◽  
The Gulf Of Finland

Our recent knowledge of the chemistry of the seafloor of the Baltic Sea has been gained during the last century only and most of it during the last three to four decades. When thinking about the start of the industrialization it seems unfortunately late. However, fortunately the seafloor archives all environmental changes in the sedimentary column like pages in a book and they can be later observed and interpreted. The Geological Survey of Finland has performed seabed geochemistry studies for decades. The first studies were performed onboard cruises of the old research vessel Aranda and later on the new Aranda as well as on the surveys on our own vessels Geola, Kaita, and Geomari. A great part of the work has been done as collaboration in international research programmes, but especially the Marine Ecogeological Patrol by the A. P. Karpinsky Russian Geological Research Institute has been of great importance for Gulf of Finland studies and as a trigger for later studies in the Gulf of Finland as well as the Baltic Sea.

scholarly journals Rapid environmental responses to climate-induced hydrographic changes in the Baltic Sea entrance

2019 ◽  
Author(s):  
Laurie M. Charrieau ◽  
Karl Ljung ◽  
Frederik Schenk ◽  
Ute Daewel ◽  
Emma Kritzberg ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Baltic Sea ◽  
Oxygen Concentration ◽  
Environmental Conditions ◽  
Nutrient Loading ◽  
Environmental Changes ◽  
Organic Matter Content ◽  
Sediment Geochemistry ◽  
Sandy Sediment ◽  
Dissolved Oxygen Concentration

Abstract. The Öresund (the Sound), which is a part of the Danish straits, is linking the marine North Sea and the brackish Baltic Sea. It is a transition zone where ecosystems are subjected to large gradients in terms of salinity, temperature, carbonate chemistry, and dissolved oxygen concentration. In addition to the highly variable environmental conditions, the area is responding to anthropogenic disturbances in e.g. nutrient loading, temperature, and pH. We have reconstructed environmental changes in the Öresund during the last c. 200 years, and especially dissolved oxygen concentration, salinity, organic matter content, and pollution levels, using benthic foraminifera and sediment geochemistry. Five zones with characteristic foraminiferal assemblages were identified, each reflecting the environmental conditions for respective period. The largest changes occurred ~ 1950, when the foraminiferal assemblage shifted from a low diversity fauna, dominated by the species Stainforthia fusiformis to higher diversity and abundance, and dominance of the Elphidium group. Concurrently, the grain-size distribution shifted from clayey – to more sandy sediment. To explore the causes for the environmental changes, we used time-series of reconstructed wind conditions coupled with large-scale climate variations as recorded by the NAO index, as well as the ECOSMO II model of currents in the Öresund area. The results indicate increased changes in the water circulation towards stronger currents in the area since the 1950's. The foraminiferal fauna responded quickly (

scholarly journals Metagenomics Uncovers a Core SAR11 Population in Brackish Surface Waters of the Baltic Sea

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 501 ◽  
Author(s):  
Poorna Vidanage ◽  
Seok-Oh Ko ◽  
Seungdae Oh
Keyword(s):  
Baltic Sea ◽  
Relative Abundance ◽  
Surface Waters ◽  
Environmental Changes ◽  
Rrna Gene ◽  
The Baltic Sea ◽  
Bacterial Populations ◽  
The Core ◽  
The Baltic ◽  
Seasonal Shifts

The Baltic Sea represents one of the largest brackish ecosystems where various environmental factors control dynamic seasonal shifts in the structure, diversity, and function of the planktonic microbial communities. In this study, despite seasonal fluctuations, several bacterial populations (<2% of the total OTUs) that are highly dominant (25% of relative abundance) and highly frequently occurring (>85% of occurrence) over four seasons were identified. Mathematical models using occurrence frequency and relative abundance data were able to describe community assembly persisting over time. Further, this work uncovered one of the core bacterial populations phylogenetically affiliated to SAR11 subclade IIIa. The analysis of the hypervariable region of 16S rRNA gene and single copy housekeeping genes recovered from metagenomic datasets suggested that the population was unexpectedly evolutionarily closely related to those inhabiting a mesosaline lacustrine ecosystem rather than other marine/coastal members. Our metagenomic results further revealed that the newly-identified population was the major driver facilitating the seasonal shifts in the overall community structure over the brackish waters of the Baltic Sea. The core community uncovered in this study supports the presence of a brackish water microbiome distinguishable from other marine and freshwater counterparts and will be a useful sentinel for monitoring local/global environmental changes posed on brackish surface waters.

When were the straits between the Baltic Sea and the Kattegat inundated by the sea during the Holocene?

Boreas ◽  
2021 ◽  
Author(s):  
Ole Bennike ◽  
Jørn Bo Jensen ◽  
Niels Nørgaard‐Pedersen ◽  
Katrine Juul Andresen ◽  
Marit‐Solveig Seidenkrantz ◽  
...  
Keyword(s):  
Baltic Sea ◽  
The Baltic Sea ◽  
The Holocene ◽  
The Baltic

Environmental evolution and anthropogenic forcing in the Garigliano coastal plain (Italy) during the Holocene

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Halinka Di Lorenzo ◽  
Pietro Aucelli ◽  
Giuseppe Corrado ◽  
Mario De Iorio ◽  
Marcello Schiattarella ◽  
...  
Keyword(s):  
Human Activity ◽  
Coastal Plain ◽  
Forest Cover ◽  
Environmental Changes ◽  
Pollen Data ◽  
Human Environment ◽  
The Holocene ◽  
Natural Processes ◽  
History Of ◽  
The Rich

The Garigliano alluvial-coastal plain, at the Latium-Campania border (Italy), witnessed a long-lasting history of human-environment interactions, as demonstrated by the rich archaeological knowledge. With the aim of reconstructing the evolution of the landscape and its interaction with human activity during the last millennia, new pollen results from the coastal sector of the Garigliano Plain were compared with the available pollen data from other nearby sites. The use of pollen data from both the coastal and marine environment allowed integrating the local vegetation dynamics within a wider regional context spanning the last 8000 years. The new pollen data presented in this study derive from the analysis of a core, drilled in the coastal sector, which intercepted the lagoon-marshy environments that occurred in the plain as a response to the Holocene transgression and subsequent coastal progradation. Three radiocarbon ages indicate that the chronology of the analyzed core interval ranges from c. 7200 to c. 2000 cal yr BP. The whole data indicate that a dense forest cover characterized the landscape all along the Prehistoric period, when a few signs of human activity are recorded in the spectra, such as cereal crops, pasture activity and fires. The main environmental changes, forced by natural processes (coastal progradation) but probably enhanced by reclamation works, started from the Graeco-Roman period and led to the reduction of swampy areas that favoured the colonisation of the outer plain.

The Upper Cretaceous foraminiferal record of IODP Site U1512 (Great Australian Bight, Indian Ocean)

2021 ◽  
Author(s):  
Erik Wolfgring ◽  
Michael A. Kaminski ◽  
Anna Waśkowska ◽  
Maria Rose Petrizzo ◽  
Eun Young Lee ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Ocean Circulation ◽  
Planktonic Foraminifera ◽  
Late Eocene ◽  
Foraminiferal Assemblage ◽  
Benthic Foraminiferal Assemblage ◽  
International Ocean Discovery Program ◽  
Foraminiferal Record ◽  
Great Australian Bight ◽  
Microfossil Assemblage

&lt;p&gt;Site U1512 was drilled during Expedition 369 of the International Ocean Discovery Program (IODP), which is located in the Great Australian Bight, southern Indian Ocean. It provides exceptional insights into the benthic foraminiferal biostratigraphy and paleoecology of a high southern latitude restricted marginal marine basin during the Late Cretaceous hot greenhouse climate and the rifting between Australia and Antarctica. The sedimentary sequence recovered at Site U1512 presents a rare record of a deep water agglutinated foraminifera (DWAF) community from the Southern High Latitudes. The Cretaceous record at Site U1512 covers the lower Turonian through Santonian (nannofossil zones UC8b to UC12/CC10b to CC16, &lt;em&gt;H. helvetica&lt;/em&gt; to &lt;em&gt;Marginotruncana&lt;/em&gt; spp. - &lt;em&gt;Planoheterohelix papula&lt;/em&gt; - &lt;em&gt;Globotruncana linneana&lt;/em&gt; planktonic foraminifera zones). Diverse benthic foraminiferal assemblages yield many new taxa that are yet to be described.&lt;/p&gt;&lt;p&gt;Agglutinated forms dominate the assemblage in most intervals. In lower to mid Turonian and Santonian strata, calcareous benthic as well as planktonic foraminifera are frequent. Abundant radiolaria are recovered from the mid Turonian, and they increase up-section and exceed 50% of the microfossil assemblage. We documented a diverse benthic foraminiferal assemblage consisting of 162 taxa (110 agglutinated and 52 calcareous). The most common taxa of the DWAF assemblage are tubular (i.e., &lt;em&gt;Kalamopsis grzybowskii,&lt;/em&gt; &lt;em&gt;Bathysiphon&lt;/em&gt; spp.) and planispiral forms (i.e., &lt;em&gt;Ammodiscus&lt;/em&gt; spp., &lt;em&gt;Haplophragmoides&lt;/em&gt; spp., &lt;em&gt;Buzasina&lt;/em&gt; sp., &lt;em&gt;Labrospira&lt;/em&gt; spp.).&lt;/p&gt;&lt;p&gt;The Turonian strata yield highly abundant &lt;em&gt;Bulbobaculites problematicus&lt;/em&gt; and &lt;em&gt;Spiroplectammina navarroana&lt;/em&gt;. The presence of the agglutinated foraminiferal marker taxa &lt;em&gt;Uvigerinammina jankoi&lt;/em&gt; and &lt;em&gt;Bulbobaculites problematicus&lt;/em&gt; provides a tie-point to the Tethyan DWAF biozonation of Geroch and Nowak (1984). The composition of foraminiferal assemblages and the increase in radiolaria abundance suggest unstable environmental conditions at Site U1512 during the early Turonian through Santonian. These characteristics refer to changes in bathymetry associated with changing ocean chemistry. Results of quantitative analyses of the benthic foraminiferal assemblages indicate a restricted paleoenvironmental regime, dictated by changes in paleobathymetry, unstable patterns in ocean circulation, and the discharge of a nearby river delta system.&lt;/p&gt;&lt;p&gt;References: Geroch, S., Nowak, K., 1984. Proposal of zonation for the Late Tithonian &amp;#8211; late Eocene. based upon arenaceous Foraminifera from the Outer Carpathians, Poland, 225-239, In: Oertli, H.J. (Ed.), Benthos &amp;#180;83; 2nd international 915 Symposium on Benthic Foraminifera, Pau (France) April 11-15, 1983, Elf Aquitaine, ESO REP and TOTAL CFP, Pau and Bordeaux.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

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