Particulate Organic Matter in Permeable Marine Sands—Dynamics in Time and Depth

Rusch, Antje; Huettel, Markus; Förster, Stefan

doi:10.1006/ecss.2000.0687

Cited by 54 publications

(19 citation statements)

References 37 publications

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“…However the use of whole-core incubation technique is not well adapted for the sandy zones exposed to the waves. Fluxes were certainly underestimated because pore water renewal (i.e., pumping effect; Rusch et al 2000) was not taken into account. Recent studies suggest that large volumes of water generally flush through permeable sands.…”

Section: Temporal Variability and Mineralization Processesmentioning

confidence: 98%

Spatio-temporal variability in benthic mineralization processes in the eastern English Channel

Rauch

Denis

2008

Biogeochemistry

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The effect of phytodetritus derived from Phaeocystis sp. bloom on benthic mineralization processes has been determined at four intertidal stations along the French coast of the eastern English Channel. Sites were chosen to offer a diversity of sediment types, from permeable sandy beach to estuarine mudflats. Sediment Oxygen Demand (SOD) as well as total fluxes of Dissolved Inorganic Nitrogen (DIN) at the sediment-water interface were determined by using whole core incubation technique and diffusive fluxes were predicted from interstitial water concentrations. In the absence of phytodetritus deposits, a marked gradient of granulometric characteristics and organic matter contents were observed, and resulted in more intensive mineralization processes in muddy sediments. Highly significant correlations (P \ 0.05) were evidenced between SOD and porosity, bacterial biomass, Organic Carbon and Organic Nitrogen, evidencing the direct link between sediment texture, organic matter accumulation and microbial activity. The spring bloom led to a massive input of organic matter in surficial sediments and mineralization rates significantly increased while higher DIN release towards the water column was observed. A modification of the mineralization pathways was evidenced but clearly depended on the sediment type. With a global view, benthic mineralization processes in the intertidal zone provided significant a part of DIN inputs in the coastal zone while water column was depleted in nutrients.

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Section: Temporal Variability and Mineralization Processesmentioning

confidence: 98%

Spatio-temporal variability in benthic mineralization processes in the eastern English Channel

Rauch

Denis

2008

Biogeochemistry

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“…Therefore, the delivery and transport of reactive carbon into the beach aquifer is a principal factor controlling the rates and distribution of biogeochemical reactions within the circulation cell. Continental shelf and intertidal sandflat sediments have been shown to entrap organic matter, bacteria, and particles which then undergo bioturbation, resuspension, and/or degradation (Bacon et al, ; Huettel & Rusch, ; Pilditch & Miller, ; Rusch et al, ; Rusch & Huettel, ). Analogously, beach sediments also act like a filter, entrapping fine particles (Anschutz et al, ; Charbonnier et al, ; McLachlan et al, ) and bacteria (Gast et al, ), resulting in spatial variations in the respiration rate of sediments (Beck et al, ).…”

Section: Introductionmentioning

confidence: 99%

Hydrologic Shifts Create Complex Transient Distributions of Particulate Organic Carbon and Biogeochemical Responses in Beach Aquifers

et al. 2019

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Biogeochemical reactions within intertidal zones of coastal aquifers have been shown to alter the concentrations of terrestrial solutes prior to their discharge to surface waters. In organic‐poor sandy aquifers, the input of marine organic matter from infiltrating seawater supports active biogeochemical reactions within the sediments. However, while the seasonality of surface water organic carbon concentrations (primary production) and groundwater mixing have been documented, there is limited understanding of the transience of various organic carbon pools (pore water particulate, dissolved, sedimentary) within the aquifer and how these relate to the location and magnitudes of biogeochemical reactions over time. To understand the relationship between changes in groundwater flow and the seasonal migration of geochemical patterns, beach pore water and sediment samples were collected and analyzed from six field sampling events spanning 2 years. While the seasonally dynamic patterns of aerobic respiration closely followed those of salinity, redox conditions and nutrient characteristics (distributions of N and P, denitrification rates) were unrelated to contemporaneous salinity patterns. This divergence was attributed to the spatial variations of reactive particulate organic carbon distributions, unrelated to salinity patterns, likely due to filtration, retardation, and immobilization dynamics during transport within the sediments. Results support a “carbon memory” effect within the beach, with the evolution and migration of reaction patterns relating to the distribution of these scattered carbon pools as more mobile solutes move over less mobile pools during changes in hydrologic conditions. This holds important implications for the prediction and quantification of biogeochemical reactions within beach systems.

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“…This process often homogenizes otherwise separated microbial populations by inducing changes in oxygen distribution and penetration. Despite the low abundance of bacteria in sandy sediments compared to finer compartments (Llobet‐Brossa et al ., 1998), bacterial assemblages in sandy sediments are characterized by high organic carbon turnover rates (Huettel and Rusch, 2000; Rusch et al ., 2000) as well as elevated rates of oxygen consumption (F. Janssen, M. Huettel and U. Witte, submitted).…”

Section: Introductionmentioning

confidence: 99%

The microbial community structure of different permeable sandy sediments characterized by the investigation of bacterial fatty acids and fluorescence in situ hybridization

Bühring

Elvert

Witte

2004

Environmental Microbiology

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This study describes the microbial community structure of three sandy sediment stations that differed with respect to median grain size and permeability in the German Bight of the Southern North Sea. The microbial community was investigated using lipid biomarker analyses and fluorescence in situ hybridization. For further characterization we determined the stable carbon isotope composition of the biomarkers. Biomarkers identified belong to different bacterial groups such as members of the Cytophaga-Flavobacterium cluster and sulfate-reducing bacteria (SRB). To support these findings, investigations using different fluorescent in situ hybridization probes were performed, specifically targeting Cytophaga-Flavobacterium, gamma-Proteobacteria and different members of the SRB. Depth profiles of bacterial fatty acid relative abundances revealed elevated subsurface peaks for the fine sediment, whereas at the other sandy sediment stations the concentrations were less variable with depth. Although oxygen penetrates deeper into the coarser and more permeable sediments, the SRB biomarkers are similarly abundant, indicating suboxic to anoxic niches in these environments. We detected SRB in all sediment types as well as in the surface and at greater depth, which suggests that SRB play a more important role in oxygenated marine sediments than previously thought.

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Particulate Organic Matter in Permeable Marine Sands—Dynamics in Time and Depth

Cited by 54 publications

References 37 publications

Spatio-temporal variability in benthic mineralization processes in the eastern English Channel

Spatio-temporal variability in benthic mineralization processes in the eastern English Channel

Hydrologic Shifts Create Complex Transient Distributions of Particulate Organic Carbon and Biogeochemical Responses in Beach Aquifers

The microbial community structure of different permeable sandy sediments characterized by the investigation of bacterial fatty acids and fluorescence in situ hybridization

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