Benthic solute exchange and carbon mineralization in two shallow subtidal sandy sediments: Effect of advective pore-water exchange

Freshwater mussels are in decline worldwide, but it remains challenging to link specific stressors to mussel declines. The clubshell mussel (Pleurobema clava) is a federally endangered species that spends most of its life completely buried beneath stream sediments. We tested the hypothesis that clubshell’s decline stems, in part, from low pore water dissolved oxygen (DO) concentrations and toxic ammonia (NH3) levels, resulting from sedimentation of interstitial pore spaces. We measured pore water DO, NH3, interstitial sedimentation rates, and sediment organic matter content in the Tippecanoe River (Indiana, USA) at sites that spanned a range of clubshell populations, including two sites devoid of clubshell. We found little evidence for pore water NH3 stress, but pore water DO generally declined with clubshell population and dipped below stress thresholds more frequently at non-clubshell sites than at sites with clubshell. In addition, interstitial sedimentation rates generally increased as clubshell populations declined, suggesting that the low DO concentrations were the result of decreased pore water – surface water exchange. As a result, we conclude that maintaining or improving habitat for clubshell mussels will require the reduction of riverine sediment loading.

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A seasonal 222Rn mass-balance of Lake Burullus, Egypt: Indications for higher pore water exchange rates during the dry season

Journal of Environmental Radioactivity ◽

10.1016/j.jenvrad.2020.106368 ◽

2021 ◽

Vol 226 ◽

pp. 106368

Author(s):

Noha Imam ◽

Nils Moosdorf ◽

Till Oehler ◽

Afaf Nada

Keyword(s):

Exchange Rates ◽

Mass Balance ◽

Pore Water ◽

Water Exchange ◽

Dry Season ◽

Lake Burullus

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Advective pore-water exchange driven by surface gravity waves and its ecological implications

Limnology and Oceanography ◽

10.4319/lo.2003.48.4.1674 ◽

2003 ◽

Vol 48 (4) ◽

pp. 1674-1684 ◽

Cited By ~ 128

Author(s):

Elimar Precht ◽

Markus Huettel

Keyword(s):

Pore Water ◽

Gravity Waves ◽

Water Exchange ◽

Surface Gravity ◽

Surface Gravity Waves ◽

Ecological Implications

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A simple pore-water sampler for coarse, sandy sediments of low porosity

Limnology and Oceanography ◽

10.4319/lo.1990.35.3.0747 ◽

1990 ◽

Vol 35 (3) ◽

pp. 747-751 ◽

Cited By ~ 28

Author(s):

Paul M. Saager ◽

Jean-Pierre Sweerts ◽

Hans J. Ellermeijer

Keyword(s):

Pore Water ◽

Water Sampler ◽

Sandy Sediments ◽

Pore Water Sampler ◽

Low Porosity

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Biogeochemical carbon transformations in a drained coastal peatland of the southern Baltic Sea: An isotope and trace element perspective

10.5194/egusphere-egu21-8022 ◽

2021 ◽

Author(s):

Anna-Kathrina Jenner ◽

Iris Schmiedinger ◽

Jens Kallmeyer ◽

Cordula Gutekunst ◽

Gerald Jurasinski ◽

...

Keyword(s):

Organic Matter ◽

Trace Metals ◽

Baltic Sea ◽

Pore Water ◽

Research Training ◽

Isotope Composition ◽

Carbon Mineralization ◽

Training Group ◽

Iron Cycling ◽

Coast Line

Peatlands serve as important ecosystems since they store a substantial fraction of global soil carbon. Through draining the internal biogeochemical processes may be changed impacting the transformation of stored carbon and plant material. Pristine peatlands are primarily associated with methanogenic and iron-cycling conditions, however, minor sulfur cycling may contribute to carbon mineralization in these ecosystems depending on the amount of atmospheric sulfur deposition and accumulation. In near coastal peatlands the element budget may be altered through natural or artificial flooding by brackish/marine waters. When introducing sulfate-bearing solutions, the concentrations of electron acceptors for anaerobic mineralization or organic matter increase when compared to fresh water conditions. The investigated area is planned to be flooded by Baltic Sea coastal waters in the near future.Here we present results from a study from a drained peatland located in the southern part of the Baltic Sea. In the past the area was agriculturally used as grassland. Soil cores were retrieved along a transect perpendicular to the coast line for (isotope) biogeochemical analyses of pore water and solid phases. Analyses included the CNS composition of soils, and dissolved major elements, nutrients, sulphide, trace metals and stable isotopes of water, DIC, and sulfate (H, O, C, S). Furthermore, acid-extractions of metals were carried out to identify zones of dissolution and formation of authigenic phases. For quantification of microbial sulphate reduction rates (SRR) additional cores were retrieved and SRR were measured in whole-core incubations.&#160;The pore water isotopic composition is close to the local meteoric water line at the German Baltic Seas coast line. Concentration and stable isotope composition of DIC indicate mineralization of C3 type organic matter. Pore water trace metals content indicates the importance of anaerobic mineralization for release of metals into the pore and surface waters.&#160;Acknowledgement: This study is supported by the DFG research training group BALTIC TRANSCOAST and Leibniz IOW.

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