scholarly journals Holocene Spatiotemporal Redox Variations in the Southern Baltic Sea

2021 ◽  
Vol 9 ◽  
Author(s):  
Dalton S. Hardisty ◽  
Natascha Riedinger ◽  
Noah J. Planavsky ◽  
Dan Asael ◽  
Steven M. Bates ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Solid Phase ◽  
Bornholm Basin ◽  
The Holocene ◽  
Isotope Data ◽  
Fe Speciation ◽  
Baltic Proper ◽  
Southern Baltic ◽  
The Baltic ◽  
Ancylus Lake

Low oxygen conditions in the modern Baltic Sea are exacerbated by human activities; however, anoxic conditions also prevailed naturally over the Holocene. Few studies have characterized the specific paleoredox conditions (manganous, ferruginous, euxinic) and their frequency in southern Baltic sub-basins during these ancient events. Here, we apply a suite of isotope systems (Fe, Mo, S) and associated elemental proxies (e.g., Fe speciation, Mn) to specifically define water column redox regimes through the Baltic Holocene in a sill-proximal to sill-distal transect (Lille Belt, Bornholm Basin, Landsort Deep) using samples collected during the Integrated Ocean Drilling Program Expedition 347. At the sill-proximal Lille Belt, there is evidence for anoxic manganous/ferruginous conditions for most of the cored interval following the transition from the Ancylus Lake to Littorina Sea but with no clear excursion to more reducing or euxinic conditions associated with the Holocene Thermal Maximum (HTM) or Medieval Climate Anomaly (MCA) events. At the sill-distal southern sub-basin, Bornholm Basin, a combination of Fe speciation, pore water Fe, and solid phase Mo concentration and isotope data point to manganous/ferruginous conditions during the Ancylus Lake-to-Littorina Sea transition and HTM but with only brief excursions to intermittently or weakly euxinic conditions during this interval. At the western Baltic Proper sub-basin, Landsort Deep, new Fe and S isotope data bolster previous Mo isotope records and Fe speciation evidence for two distinct anoxic periods but also suggest that sulfide accumulation beyond transient levels was largely restricted to the sediment-water interface. Ultimately, the combined data from all three locations indicate that Fe enrichments typically indicative of euxinia may be best explained by Fe deposition as oxides following events likely analogous to the periodic incursions of oxygenated North Sea waters observed today, with subsequent pyrite formation in sulfidic pore waters. Additionally, the Mo isotope data from multiple Baltic Sea southern basins argue against restricted and widespread euxinic conditions, as has been demonstrated in the Baltic Proper and Bothnian Sea during the HTM or MCA. Instead, similar to today, each past Baltic anoxic event is characterized by redox conditions that become progressively more reducing with increasing distance from the sill.

scholarly journals Ferruginous groundwaters as a source of P, Fe, and DIC for coastal waters of the southern Baltic Sea: (Isotope) hydrobiogeochemistry and the role of an iron curtain

2018 ◽  
Vol 54 ◽  
pp. 00019
Author(s):  
Marko Lipka ◽  
Michael E. Böttcher ◽  
Zijun Wu ◽  
Jürgen Sültenfuß ◽  
Anna-K. Jenner ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Ground Water ◽  
Sea Water ◽  
Solid Phase ◽  
Glacial Sediments ◽  
Southern Baltic Sea ◽  
Biogenic Carbon ◽  
First Results ◽  
Southern Baltic ◽  
The Baltic

We report first results from a study on water and element exchange across the land-ocean boundary at the southern Baltic Sea. The focus is set on ferruginous fresh ground waters escaping at the shore line, flowing in air contact before entering a subterranean mixing zone with brackish Baltic Sea water. The present study combines the results from multiple sampling campaigns that investigated the composition of several springs as well as the surface and subsurface development of fresh waters on the way to the Baltic Sea. This is achieved by a combination of hydroand solid-phase geochemical and stable isotope measurements with ground water dating. Results are compared to the composition of groundwaters recovered from wells in the catchment area and the local isotope meteoric water line developed for Warnemünde. The spring water is shown to be impacted by the dissolution of biogenic carbon dioxide and marine carbonate as well as the oxidation of pyrite in glacial sediments. Dating yields a surprisingly high diversity between some closely associated springs with average ages of about 25 to 32 years, but different mixing proportions with older tritium-free ground-water.

scholarly journals The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: an evaluation of their application as tracers of past nitrogen fixation

2017 ◽  
Vol 14 (24) ◽  
pp. 5789-5804 ◽  
Author(s):  
Martina Sollai ◽  
Ellen C. Hopmans ◽  
Nicole J. Bale ◽  
Anchelique Mets ◽  
Lisa Warden ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Cyanobacterial Blooms ◽  
The Baltic Sea ◽  
The Holocene ◽  
Heterocystous Cyanobacteria ◽  
Cyanobacterial Species ◽  
The Baltic ◽  
Abundance And Distribution ◽  
Yoldia Sea ◽  
Ancylus Lake

Abstract. Heterocyst glycolipids (HGs) are lipids exclusively produced by heterocystous dinitrogen-fixing cyanobacteria. The Baltic Sea is an ideal environment to study the distribution of HGs and test their potential as biomarkers because of its recurring summer phytoplankton blooms, dominated by a few heterocystous cyanobacterial species of the genera Nodularia and Aphanizomenon. A multi-core and a gravity core from the Gotland Basin were analyzed to determine the abundance and distribution of a suite of selected HGs at a high resolution to investigate the changes in past cyanobacterial communities during the Holocene. The HG distribution of the sediments deposited during the Modern Warm Period (MoWP) was compared with those of cultivated heterocystous cyanobacteria, including those isolated from Baltic Sea waters, revealing high similarity. However, the abundance of HGs dropped substantially with depth, and this may be caused by either a decrease in the occurrence of the cyanobacterial blooms or diagenesis, resulting in partial destruction of the HGs. The record also shows that the HG distribution has remained stable since the Baltic turned into a brackish semi-enclosed basin ∼ 7200 cal. yr BP. This suggests that the heterocystous cyanobacterial species composition remained relatively stable as well. During the earlier freshwater phase of the Baltic (i.e., the Ancylus Lake and Yoldia Sea phases), the distribution of the HGs varied much more than in the subsequent brackish phase, and the absolute abundance of HGs was much lower than during the brackish phase. This suggests that the cyanobacterial community adjusted to the different environmental conditions in the basin. Our results confirm the potential of HGs as a specific biomarker of heterocystous cyanobacteria in paleo-environmental studies.

scholarly journals The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: Evaluation of their application as tracers of past nitrogen fixation

2017 ◽  
Author(s):  
Martina Sollai ◽  
Ellen C. Hopmans ◽  
Nicole J. Bale ◽  
Anchelique Mets ◽  
Matthias Moros ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Cyanobacterial Blooms ◽  
The Baltic Sea ◽  
The Holocene ◽  
Heterocystous Cyanobacteria ◽  
Cyanobacterial Species ◽  
The Baltic ◽  
Abundance And Distribution ◽  
Ancylus Lake ◽  
Partial Destruction

Abstract. Heterocyst glycolipids (HGs) are lipids exclusively produced by heterocystous dinitrogen-fixing cyanobacteria. The Baltic Sea is an ideal environment to study the distribution of HGs and test their potential as biomarkers because of its recurring summer phytoplankton blooms, dominated by a few heterocystous cyanobacterial species. A multicore and a gravity core from the Gotland basin were analyzed to determine the abundance and distribution of HGs at high resolution to investigate the changes in past cyanobacterial communities during the Holocene. The HG distribution of the sediments deposited during the Modern Warm Period (MoWP) was compared with those of cultivated heterocystous cyanobacteria, revealing high similarity. However, the abundance of HGs dropped substantially with depth and this may be caused by either a decrease of the cyanobacterial blooms or diagenesis, resulting in partial destruction of the HGs. The record also shows that the HGs distribution has remained stable since the Baltic has turned into a brackish semi-enclosed basin ~ 7200 yrs BP. This suggests that the heterocystous cyanobacterial species composition remained relatively stable as well. During the earlier freshwater phase of the Baltic (i.e. the Ancylus Lake phase) the distribution of the HGs varied much more than in the subsequent brackish phase and the absolute abundance of HGs was much lower than during the brackish phase. This suggests that the cyanobacterial community adjusted to the different environmental conditions in the basin. Our results confirm the potential of HGs as specific biomarker of heterocystous cyanobacteria in paleo-environmental studies.

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)

2008 ◽  
Vol 37 (4) ◽  
Author(s):  
Małgorzata Leśniewska ◽  
Małgorzata Witak
Keyword(s):  
Baltic Sea ◽  
The South ◽  
Gulf Of Gdańsk ◽  
The Baltic Sea ◽  
Southern Baltic Sea ◽  
Gulf Of Gdansk ◽  
Southern Baltic ◽  
The Baltic ◽  
Palaeoenvironmental Changes

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)The palaeoenvironmental changes of the south-western part of the Gulf of Gdańsk during the last 8,000 years, with reference to the stages of the Baltic Sea, were reconstructed. Diatom analyses of two cores taken from the shallower and deeper parts of the basin enabled the conclusion to be drawn that the microflora studied developed in the three Baltic phases: Mastogloia, Littorina and Post-Littorina. Moreover, the so-called anthropogenic assemblage was observed in subbottom sediments of the study area.

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

scholarly journals Nutrient transports in the Baltic Sea – results from a 30-year physical–biogeochemical reanalysis

2017 ◽  
Vol 14 (8) ◽  
pp. 2113-2131 ◽  
Author(s):  
Ye Liu ◽  
H. E. Markus Meier ◽  
Kari Eilola
Keyword(s):  
Baltic Sea ◽  
Cross Sections ◽  
Ocean Model ◽  
Optimal Interpolation ◽  
Nutrient Concentrations ◽  
Biogeochemical Model ◽  
The Baltic Sea ◽  
Gulf Of Riga ◽  
Baltic Proper ◽  
The Baltic

Abstract. Long-term oxygen and nutrient transports in the Baltic Sea are reconstructed using the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the Rossby Centre Ocean model (RCO). Two simulations with and without data assimilation covering the period 1970–1999 are carried out. Here, the weakly coupled scheme with the Ensemble Optimal Interpolation (EnOI) method is adopted to assimilate observed profiles in the reanalysis system. The reanalysis shows considerable improvement in the simulation of both oxygen and nutrient concentrations relative to the free run. Further, the results suggest that the assimilation of biogeochemical observations has a significant effect on the simulation of the oxygen-dependent dynamics of biogeochemical cycles. From the reanalysis, nutrient transports between sub-basins, between the coastal zone and the open sea, and across latitudinal and longitudinal cross sections are calculated. Further, the spatial distributions of regions with nutrient import or export are examined. Our results emphasize the important role of the Baltic proper for the entire Baltic Sea, with large net transport (export minus import) of nutrients from the Baltic proper into the surrounding sub-basins (except the net phosphorus import from the Gulf of Riga and the net nitrogen import from the Gulf of Riga and Danish Straits). In agreement with previous studies, we found that the Bothnian Sea imports large amounts of phosphorus from the Baltic proper that are retained in this sub-basin. For the calculation of sub-basin budgets, the location of the lateral borders of the sub-basins is crucial, because net transports may change sign with the location of the border. Although the overall transport patterns resemble the results of previous studies, our calculated estimates differ in detail considerably.

The first large-scale assessment of three-spined stickleback (Gasterosteus aculeatus) biomass and spatial distribution in the Baltic Sea

2019 ◽  
Vol 76 (6) ◽  
pp. 1653-1665 ◽  
Author(s):  
Jens Olsson ◽  
Eglė Jakubavičiūtė ◽  
Olavi Kaljuste ◽  
Niklas Larsson ◽  
Ulf Bergström ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Baltic Sea ◽  
Gasterosteus Aculeatus ◽  
Population Characteristics ◽  
Alternative Methods ◽  
The Baltic Sea ◽  
Baltic Proper ◽  
The Baltic ◽  
The Impact ◽  
Bothnian Sea

Abstract Declines in predatory fish in combination with the impact of climate change and eutrophication have caused planktivores, including three-spined stickleback (Gasterosteus aculeatus), to increase dramatically in parts of the Baltic Sea. Resulting impacts of stickleback on coastal and offshore foodwebs have been observed, highlighting the need for increased knowledge on its population characteristics. In this article, we quantify abundance, biomass, size structure, and spatial distribution of stickleback using data from the Swedish and Finnish parts of the Baltic International Acoustic Survey (BIAS) during 2001–2014. Two alternative methods for biomass estimation suggest an increase in biomass of stickleback in the Baltic Proper, stable or increasing mean size over time, and larger individuals toward the north. The highest abundance was found in the central parts of the Baltic Proper and Bothnian Sea. The proportion of stickleback biomass in the total planktivore biomass increased from 4 to 10% in the Baltic Proper and averaged 6% of the total planktivore biomass in the Bothnian Sea. In some years, however, stickleback biomass has ranged from half to almost twice that of sprat (Sprattus sprattus) in both basins. Given the recent population expansion of stickleback and its potential role in the ecosystem, we recommend that stickleback should be considered in future monitoring programmes and in fisheries and environmental management of the Baltic Sea.

scholarly journals Geoelectric Monitoring of Wind-Driven Barotropic Transports in the Baltic Sea

2007 ◽  
Vol 24 (9) ◽  
pp. 1655-1664 ◽  
Author(s):  
Jenny A. U. Nilsson ◽  
Peter Sigray ◽  
Robert H. Tyler
Keyword(s):  
Baltic Sea ◽  
Circulation Model ◽  
Correlation Study ◽  
The Baltic Sea ◽  
Barotropic Flow ◽  
Spatial Coverage ◽  
Baltic Proper ◽  
The Baltic ◽  
Scale Motion ◽  
Geoelectric Monitoring

Abstract The possibility of using data from a cable-based observational system for long-term monitoring of barotropic flow in the Baltic Sea was investigated. Measurements were made of the induced potential differences between Visby on the island of Gotland and Västervik on the Swedish mainland and a yearlong period was studied in order to ensure the presence of seasonal fluctuations. The predictions from a 2D electric-potential model, forced by velocity fields from a shallow-water circulation model, proved to be well correlated with the observations. A winter and a summer period were selected for a thorough analysis, the results of which indicated a stronger correlation during winter. This implies that the relative importance of the barotropic forcing tends to weaken during summer. The spatial coverage of the induced potential differences for the cable region was found to encompass a considerable part of the Baltic proper. The correlation study indicated that the winter circulation in the Baltic proper showed “broad-scale” motion, whereas summer conditions were characterized by a barotropic gyre. An overall result of the investigation is that geoelectric monitoring is capable of providing useful data for oceanographic purposes.

Body size and reproductive traits of Palaemon elegans Rathke, 1837 (Crustacea, Decapoda), a recent colonizer of the Baltic Sea

2010 ◽  
Vol 39 (2) ◽  
Author(s):  
Urszula Janas ◽  
Anna Mańkucka
Keyword(s):  
Body Size ◽  
Baltic Sea ◽  
Reproductive Traits ◽  
The Baltic Sea ◽  
Palaemon Elegans ◽  
Southern Baltic ◽  
The Baltic

Body size and reproductive traits ofis a species of prawn new (since 2000) to the southern Baltic. The aim of this study was to find out whether there are differences in the sizes of individuals and in the reproductive traits of

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