scholarly journals The benthic foraminiferal community in a naturally CO<sub>2</sub>-rich coastal habitat of the southwestern Baltic Sea

2012 ◽  
Vol 9 (11) ◽  
pp. 4421-4440 ◽  
Author(s):  
K. Haynert ◽  
J. Schönfeld ◽  
I. Polovodova-Asteman ◽  
J. Thomsen
Keyword(s):  
Baltic Sea ◽  
Pore Water ◽  
Benthic Foraminifera ◽  
High Pco2 ◽  
Pore Waters ◽  
Coastal Habitat ◽  
Sediment Pore Water ◽  
Model Calculations ◽  
One Year ◽  
Atmospheric Co2 Concentrations

Abstract. It is expected that the calcification of foraminifera will be negatively affected by the ongoing acidification of the oceans. Compared to the open oceans, these organisms are subjected to much more adverse carbonate system conditions in coastal and estuarine environments such as the southwestern Baltic Sea, where benthic foraminifera are abundant. This study documents the seasonal changes of carbonate chemistry and the ensuing response of the foraminiferal community with bi-monthly resolution in Flensburg Fjord. In comparison to the surface pCO2, which is close to equilibrium with the atmosphere, we observed large seasonal fluctuations of pCO2 in the bottom and sediment pore waters. The sediment pore water pCO2 was constantly high during the entire year ranging from 1244 to 3324 μatm. Nevertheless, in contrast to the bottom water, sediment pore water was slightly supersaturated with respect to calcite as a consequence of higher alkalinity (AT) for most of the year. Foraminiferal assemblages were dominated by two calcareous species, Ammonia aomoriensis and Elphidium incertum, and the agglutinated Ammotium cassis. The one-year cycle was characterised by seasonal community shifts. Our results revealed that there is no dynamic response of foraminiferal population density and diversity to elevated sediment pore water pCO2. Surprisingly, the fluctuations of sediment pore water undersaturation (Ωcalc) co-vary with the population densities of living Ammonia aomoriensis. Further, we observed that most of the tests of living calcifying foraminifera were intact. Only Ammonia aomorienis showed dissolution and recalcification structures on the tests, especially at undersaturated conditions. Therefore, the benthic community is subjected to high pCO2 and tolerates elevated levels as long as sediment pore water remains supersaturated. Model calculations inferred that increasing atmospheric CO2 concentrations will finally lead to a perennial undersaturation in sediment pore waters. Whereas benthic foraminifera indeed may cope with a high sediment pore water pCO2, the steady undersaturation of sediment pore waters would likely cause a significant higher mortality of the dominating Ammonia aomoriensis. This shift may eventually lead to changes in the benthic foraminiferal communities in Flensburg Fjord, as well as in other regions experiencing naturally undersaturated Ωcalc levels.

scholarly journals The benthic foraminiferal community in a naturally CO<sub>2</sub>-rich coastal habitat in the southwestern Baltic Sea

2012 ◽  
Vol 9 (6) ◽  
pp. 7783-7830 ◽  
Author(s):  
K. Haynert ◽  
J. Schönfeld ◽  
I. Polovodova-Asteman ◽  
J. Thomsen
Keyword(s):  
Baltic Sea ◽  
Pore Water ◽  
Benthic Foraminifera ◽  
High Pco2 ◽  
Pore Waters ◽  
Coastal Habitat ◽  
Sediment Pore Water ◽  
Model Calculations ◽  
One Year ◽  
Atmospheric Co2 Concentrations

Abstract. It is expected that the calcification of foraminifera will be negatively affected by the ongoing acidification of the oceans. Compared to the open oceans, these organisms are subjected to much more adverse carbonate system conditions in coastal and estuarine environments such as the southwestern Baltic Sea, where benthic foraminifera are abundant. This study documents the seasonal changes of carbonate chemistry and the ensuing response of the foraminiferal community with bi-monthly resolution in Flensburg Fjord. In comparison to the surface pCO2, which is close to equilibrium with the atmosphere, we observed large seasonal fluctuations of pCO2 in the bottom and sediment pore waters. The sediment pore water pCO2 was constantly high during the entire year ranging from 1244 to 3324 μatm. Nevertheless, in contrast to the bottom water, sediment pore water was slightly supersaturated with respect to calcite as consequence of higher alkalinity (AT) for the most time of the year. Foraminiferal assemblages were dominated by two calcareous species, Ammonia aomoriensis and Elphidium incertum, and the agglutinated Ammotium cassis. The one year-cycle was characterized by seasonal community shifts. Our results revealed that there is no dynamic response of foraminiferal population density and diversity to elevated sediment pore water pCO2. Surprisingly, the fluctuations of sediment pore water undersaturation (Ωcalc) co-vary with the population densities of living Ammonia aomoriensis. Further, we observed that most of the tests of living calcifying specimens were intact. Only Ammonia aomorienis showed dissolution and recalcification structures on the tests, especially at undersaturated conditions. Therefore, the benthic community is subjected to constantly high pCO2 and tolerates elevated levels as long as sediment pore water remains supersaturated. Model calculations inferred that increasing atmospheric CO2 concentrations will finally lead to a perennial undersaturation in sediment pore waters. Whereas benthic foraminifera indeed may cope with a high sediment pore water pCO2, the steady undersaturation of sediment pore waters would likely cause a significant higher mortality of the dominating Ammonia aomoriensis. This shift may eventually lead to changes in the benthic foraminiferal communities in Flensburg Fjord, as well as in other regions experiencing naturally undersaturated Ωcalc levels.

Equilibrium passive sampling as a tool to study polycyclic aromatic hydrocarbons in Baltic Sea sediment pore-water systems

2015 ◽  
Vol 101 (1) ◽  
pp. 296-303 ◽  
Author(s):  
Susann-Cathrin Lang ◽  
Andrew Hursthouse ◽  
Philipp Mayer ◽  
Danjiela Kötke ◽  
Ines Hand ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Baltic Sea ◽  
Pore Water ◽  
Aromatic Hydrocarbons ◽  
Passive Sampling ◽  
Water Systems ◽  
Sediment Pore Water ◽  
Polycyclic Aromatic

Bicarbonate as a Potential Confounding Factor in Cladoceran Toxicity Assessments of Pore Water from Contaminated Sediments

1992 ◽  
Vol 49 (8) ◽  
pp. 1633-1640 ◽  
Author(s):  
Robert A. Hoke ◽  
William R. Gala ◽  
James B. Drake ◽  
John P. Giesy ◽  
Stan Flegler
Keyword(s):  
Pore Water ◽  
Ceriodaphnia Dubia ◽  
Toxicity Tests ◽  
Metabolic Inhibitor ◽  
Pore Waters ◽  
Sediment Pore Water ◽  
International Joint Commission ◽  
Reference Toxicant ◽  
Area Of Concern ◽  
Pore Water Sample

Elevated alkalinity values measured in sediment pore water samples from the Grand Calumet River–Indiana Harbor Canal, an International joint Commission Area of Concern (AOC), caused concern over the potential effects of alkalinity on cladoceran test responses. Forty-eight-hour tests with NaHCO3 and NaCl as reference toxicants indicated that NaHCO3 toxicity to Daphnia magna and Ceriodaphnia dubia was due to both Na+ and HCO3−, although greater HCO3− toxicity was observed to D. magna. Theoretical HCO3− concentrations in sediment pore waters from the AOC demonstrated sufficient HCO3− in several samples to produce acute toxicity, based on 48-h LC50s from the reference toxicant tests. X-ray microanalysis was conducted to qualitatively assess the effects on internal Cl− levels of D. magna after exposure to NaHCO3, to an AOC sediment pore water sample, and to NaSCN, a metabolic inhibitor of Cl− uptake. Based on these results the proposed mechanism of HCO3− toxicity to D. magna is the inhibition of the active uptake of Cl− from water. We suggest that pore water alkalinity should be considered when interpreting the results of sediment pore water and effluent toxicity tests with D. magna, other cladocerans, and, perhaps, other invertebrates and fish.

A multi-tracer study of submarine groundwater discharge into Wismar Bay, southern Baltic Sea

2020 ◽  
Author(s):  
Catia Milene Ehlert von Ahn ◽  
Jan Scholten ◽  
Iris Schmiedinger ◽  
Bo Liu ◽  
Michael Böttcher
Keyword(s):  
Baltic Sea ◽  
Pore Water ◽  
Surface Waters ◽  
Submarine Groundwater Discharge ◽  
Isotope Composition ◽  
Groundwater Discharge ◽  
Pore Waters ◽  
Southern Baltic Sea ◽  
Submarine Groundwater ◽  
Southern Baltic

&lt;p&gt;Submarine groundwater discharge (SGD) is considered as an important route for water and dissolved material exchange between land and coastal seas. Both freshwater and (recirculated) seawater are referred to as SGD and may impact the composition and biogeochemical processes in coastal waters. The present study focuses on the identification and the spatial variability of SGD into the Wismar Bay, in the southern Baltic Sea. On across-shore transects covering Wismar Bay waters were sampled for analysis of Radium (Ra) isotopes, stable isotopes (H, O, C, S), dissolved inorganic carbon (DIC), nutrients and major cations. In addition, sediment cores were retrieved from several stations. The detection of short-living radium isotopes (&lt;sup&gt;223&lt;/sup&gt;Ra and&lt;sup&gt;224&lt;/sup&gt;Ra) in surface waters of the bay indicate benthic-pelagic coupling via pore water exchange with the water column that may be an indication for SGD. Moreover, enhanced concentration of dissolved manganese and barium, resulted from anoxic pore waters, were found in areas with higher Ra activity. Pore water profiles of salinity and major ions highlight the presence of freshwater about 50 cmbsf in sediments in the central part of the bay, probably related to the presence of a coastal aquifer. In contrast, other sediments demonstrate relatively constant pore water salinity distribution with increasing depth. Slight salinity maxima in almost all core at around 6 to 12 cmbsf seems to be relict from changing bottom water salinity in the past. The water isotope composition (&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O, &amp;#948;&lt;sup&gt;2&lt;/sup&gt;H) of the low saline pore water is plot close to the local meteoric water line established for Warnem&amp;#252;nde. Saline pore waters, in contrast, have water isotope composition aligned with southern Baltic Sea surface waters. The DIC concentrations increased with depths suggesting the mineralization of organic matter within the 50 cm sediments depth at all sides. Moreover, the values of DIC even exceeding the concentration found on the percolating fresh ground water. Thus, the overall contribution of elements to the coastal ecosystem is a function of the transport processes regulating element flux across the sediment-water interface.&lt;/p&gt;&lt;p&gt;The investigation is supported by the DFG research training school Baltic TRANSCOAST, DAAD, and Leibniz IOW.&lt;/p&gt;

scholarly journals Hydrochemistry of sediment pore water in the Bratsk reservoir (Baikal region, Russia)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. I. Poletaeva ◽  
E. N. Tirskikh ◽  
M. V. Pastukhov
Keyword(s):  
Pore Water ◽  
Ionic Composition ◽  
Water System ◽  
Water Reservoir ◽  
Environmental Parameters ◽  
Water Area ◽  
Pore Waters ◽  
Overlying Water ◽  
Major Ion ◽  
Bratsk Reservoir

AbstractThis study aimed to identify the factors responsible for the major ion composition of pore water from the bottom sediments of the Bratsk water reservoir, which is part of the largest freshwater Baikal-Angara water system. In the Bratsk reservoir, the overlying water was characterized as HCO3–Ca–Mg type with the mineralization ranging between 101.2 and 127.7 mg L−1 and pore water was characterized as HCO3–SO4–Ca, SO4–Cl–Ca–Mg and mixed water types, which had mineralization varying from 165.9 to 4608.1 mg L−1. The ionic composition of pore waters varied both along the sediment depth profile and across the water area. In pore water, the difference between the highest and lowest values was remarkably large: 5.1 times for K+, 13 times for Mg2+, 16 times for HCO3−, 20 times for Ca2+, 23 times for Na+, 80 times for SO42−, 105 times for Cl−. Such variability at different sites of the reservoir was due to the interrelation between major ion concentrations in the pore water and environmental parameters. The major factor responsible for pore water chemistry was the dissolution of sediment-forming material coming from various geochemical provinces. In the south part of the reservoir, Cl−, Na+ and SO42− concentrations may significantly increase in pore water due to the effect of subaqueous flow of highly mineralized groundwater.

scholarly journals Phosphorous Supply to a Eutrophic Artificial Lake: Sedimentary versus Groundwater Sources

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 563
Author(s):  
Wiebe Förster ◽  
Jan C. Scholten ◽  
Michael Schubert ◽  
Kay Knoeller ◽  
Nikolaus Classen ◽  
...  
Keyword(s):  
Water Quality ◽  
Stable Isotope ◽  
Pore Water ◽  
Lake Water ◽  
Sediment Cores ◽  
Eutrophic Lake ◽  
Stable Water Isotopes ◽  
Artificial Lake ◽  
Sediment Pore Water ◽  
Mass Balance Models

The eutrophic Lake Eichbaumsee, a ~1 km long and 280 m wide (maximum water depth 16 m) dredging lake southeast of Hamburg (Germany), has been treated for water quality improvements using various techniques (i.e., aeration plants, removal of dissolved phosphorous by aluminum phosphorous precipitation, and by Bentophos® (Phoslock Environmental Technologies, Sydney, Australia), adsorption) during the past ~15 years. Despite these treatments, no long-term improvement of the water quality has been observed and the lake water phosphorous content has continued to increase by e.g., ~670 kg phosphorous between autumn 2014 and autumn 2019. As no creeks or rivers drain into the lake and hydrological groundwater models do not suggest any major groundwater discharge into the lake, sources of phosphorous (and other nutrients) are unknown. We investigated the phosphorous fluxes from sediment pore water and from groundwater in the water body of the lake. Sediment pore water was extracted from sediment cores recovered by divers in August 2018 and February 2019. Diffusive phosphorous fluxes from pore water were calculated based on phosphorus gradients. Stable water isotopes (δ2H, δ18O) were measured in the lake water, in interstitial waters in the banks surrounding the lake, in the Elbe River, and in three groundwater wells close to the lake. Stable isotope (δ2H, δ18O) water mass balance models were used to compute water inflow/outflow to/from the lake. Our results revealed pore-water borne phosphorous fluxes between 0.2 mg/m2/d and 1.9 mg/m2/d. Assuming that the measured phosphorous fluxes are temporarily and spatially representative for the whole lake, about 11 kg/a to 110 kg/a of phosphorous is released from sediments. This amount is lower than the observed lake water phosphorous increase of ~344 kg between April 2018 and November 2018. Water stable isotope (δ2H, δ18O) compositions indicate a water exchange between an aquifer and the lake water. Based on stable isotope mass balances we estimated an inflow of phosphorous from the aquifer to the lake of between ~150 kg/a and ~390 kg/a. This result suggests that groundwater-borne phosphorous is a significant phosphorous source for the Eichbaumsee and highlights the importance of groundwater for lake water phosphorous balances.

scholarly journals Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 202
Author(s):  
Meilian Chen ◽  
Ji-Hoon Kim ◽  
Sungwook Hong ◽  
Yun Kyung Lee ◽  
Moo Hee Kang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Phytoplankton Bloom ◽  
Ocean Surface ◽  
The Arctic ◽  
Sediment Pore Water ◽  
Ice Edge ◽  
Accumulation Trend ◽  
Arctic Fjords

Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties of dissolved organic matter (DOM) in both seawater and sediment pore water, along with the remote sensing data of the ocean surface, from three West Svalbard fjords. A cross-fjord comparison of fluorescence fingerprints together with downcore trends of salinity, Cl−, and PO43− revealed higher impact of terrestrial inputs (fluorescence index: ~1.2–1.5 in seawaters) and glaciofluvial runoffs (salinity: ~31.4 ± 2.4 psu in pore waters) to the southern fjord of Hornsund as compared to the northern fjords of Isfjorden and Van Mijenfjorden, tallying with heavier annual runoff to the southern fjord of Hornsund. Extremely high levels of protein-like fluorescence (up to ~4.5 RU) were observed at the partially sea ice-covered fjords in summer, in line with near-ubiquity ice-edge blooms observed in the Arctic. The results reflect an ongoing or post-phytoplankton bloom, which is also supported by the higher levels of chlorophyll a fluorescence at the ocean surface, the very high apparent oxygen utilization through the water column, and the nutrient drawdown at the ocean surface. Meanwhile, a characteristic elongated fluorescence fingerprint was observed in the fjords, presumably produced by ice-edge blooms in the Arctic ecosystems. Furthermore, alkalinity and the humic-like peaks showed a general downcore accumulation trend, which implies the production of humic-like DOM via a biological pathway also in the glaciomarine sediments from the Arctic fjords.

scholarly journals Noble gases in sediment pore water yield insights into hydrothermal fluid transport in the northern Guaymas Basin

2021 ◽  
Vol 434 ◽  
pp. 106419
Author(s):  
E. Horstmann ◽  
Y. Tomonaga ◽  
M.S. Brennwald ◽  
M. Schmidt ◽  
V. Liebetrau ◽  
...  
Keyword(s):  
Pore Water ◽  
Hydrothermal Fluid ◽  
Fluid Transport ◽  
Noble Gases ◽  
Water Yield ◽  
Sediment Pore Water ◽  
Guaymas Basin
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