Impact of cable bacteria on sedimentary iron and manganese dynamics in a seasonally-hypoxic marine basin

Sulu-Gambari, Fatimah; Seitaj, Dorina; Behrends, Thilo; Banerjee, Dipanjan; Meysman, Filip J. R.; Slomp, Caroline P.

doi:10.1016/j.gca.2016.07.028

Cited by 78 publications

(67 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, foraminiferal Mn/Ca ratios from chambers calcified under anoxic conditions should be nominal. At our station in Lake Grevelingen, which experiences hypoxic but not anoxic events in summer, these events lead to the dissolution of Mn oxides in surface sediments, and suspended-matter Mn in the water column (sampled ∼ 500 m away from our station) shows maximum values in July 2012 (Sulu-Gambari et al, 2016b. Therefore, we would expect higher Mn 2+ concentrations below the SWI in summer than in winter, coinciding with higher Mn/Ca ratios in chambers of A. tepida calcified in summer.…”

Section: Seasonality Of Environmental Factors As Explanation For Mn/cmentioning

confidence: 94%

“…After homogenization of the water column in September/October, BWO quickly rose to values of ∼ 200 µM (∼ 80 % saturation). Pore water Mn 2+ showed highest concentrations (up to 310 µM) in winter and early spring, followed by considerably lower concentrations in summer and autumn (Sulu-Gambari et al, 2016b; Fig. S3).…”

Section: Study Areamentioning

confidence: 99%

“…However, one complicating factor is that the activity of cable bacteria strongly influences the seasonal pattern of sediment geochemical cycles in Lake Grevelingen. These electrogenic bacteria induce strong shifts in the sediment geochemistry (Seitaj et al, , 2017SuluGambari et al, 2016a, b) and lead to substantial Mn 2+ mobilization in pore waters (Rao et al, 2016;Sulu-Gambari et al, 2016b;van de Velde et al, 2016). These cable bacteria tend to have a highly patchy distribution, which hence could complicate the interpretation (Sulu-Gambari et al, 2016b;Seitaj et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mn∕Ca intra- and inter-test variability in the benthic foraminifer <i>Ammonia tepida</i>

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. The adaptation of some benthic foraminiferal species to low-oxygen conditions provides the prospect of using the chemical composition of their tests as proxies for bottom water oxygenation. Manganese may be particularly suitable as such a geochemical proxy because this redox element is soluble in reduced form (Mn 2+ ) and hence can be incorporated into benthic foraminiferal tests under low-oxygen conditions. Therefore, intra-and inter-test differences in foraminiferal Mn/Ca ratios may hold important information about short-term variability in pore water Mn 2+ concentrations and sediment redox conditions. Here, we studied Mn/Ca intra-and inter-test variability in living individuals of the shallow infaunal foraminifer Ammonia tepida sampled in Lake Grevelingen (the Netherlands) in three different months of 2012. The deeper parts of this lake are characterized by seasonal hypoxia/anoxia with associated shifts in microbial activity and sediment geochemistry, leading to seasonal Mn 2+ accumulation in the pore water. Earlier laboratory experiments with similar seawater Mn 2+ concentrations as encountered in the pore waters of Lake Grevelingen suggest that intra-test variability due to ontogenetic trends (i.e. size-related effects) and/or other vital effects occurring during calcification in A. tepida (11-25 % relative SD, RSD) is responsible for part of the observed variability in Mn/Ca. Our present results show that the seasonally highly dynamic environmental conditions in the study area lead to a strongly increased Mn/Ca intra-and inter-test variability (average of 45 % RSD). Within single specimens, both increasing and decreasing trends in Mn/Ca ratios with size are observed. Our results suggest that the variability in successive single-chamber Mn/Ca ratios reflects the temporal variability in pore water Mn 2+ . Additionally, active or passive migration of the foraminifera in the surface sediment may explain part of the observed Mn/Ca variability.

show abstract

Section: Seasonality Of Environmental Factors As Explanation For Mn/cmentioning

confidence: 94%

Section: Study Areamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mn∕Ca intra- and inter-test variability in the benthic foraminifer <i>Ammonia tepida</i>

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…3 and 4). Results of Fe XANES showed that the Fe (oxy)hydroxides formed in the surface sediment in spring are mostly poorly crystalline (Sulu-Gambari et al 2016b). Our P XANES results indicate that at least part of the P is adsorbed to the surface of these Fe(III)-(oxyhydr)oxides (Figs.…”

Section: Discussionmentioning

confidence: 99%

“…The clear signals of activity in the bulk porewater geochemistry (e.g. G. maxima in calcium ion (Ca 2+ ) and sulphate (SO 4 2− ) concentrations) (Sulu-Gambari et al 2016b) suggested that cable bacteria were likely also present at site 2 in spring but were not detected with FISH because of patchiness of the sediment or because the bacteria were present at densities that fall below the detection limit of the method.…”

Section: Sediment Sampling and Site Characteristicsmentioning

confidence: 99%

Phosphorus Cycling and Burial in Sediments of a Seasonally Hypoxic Marine Basin

Sulu-Gambari

Hagens

Behrends

et al. 2017

Estuaries and Coasts

Self Cite

View full text Add to dashboard Cite

Recycling of phosphorus (P) from sediments contributes to the development of bottom-water hypoxia in many coastal systems. Here, we present results of a year-long assessment of P dynamics in sediments of a seasonally hypoxic coastal marine basin (Lake Grevelingen, the Netherlands) in 2012. Sequential phosphorus extractions (SEDEX) and X-ray absorption spectroscopy (XAS) indicate that P was adsorbed to Fe-(III)-(oxyhydr)oxides when cable bacteria were active in the surface sediments in spring. With the onset of summer h y p o x i a , s u l p h i d e -i n d u c e d d i s s o l u t i o n o f t h e Fe-(III)-(oxyhydr)oxides led to P release to the pore water and overlying water. The similarity in authigenic Ca-P concentrations in the sediment and suspended matter suggest that Ca-P is not formed in situ. The P burial efficiency was ≤ 32%. Hypoxia-driven sedimentary P recycling had a major impact on the water-column chemistry in the basin in 2012. Watercolumn monitoring data indicate up to ninefold higher surface water concentrations of phosphate in the basin in the late 1970s and a stronger hypoxia-driven seasonal P release from the sediment. The amplified release of P from the sediment in the past is attributed to the presence of a larger pool of Febound P in the basin prior to the first onset of hypoxia. Given that P is not limiting, primary production in the basin has not been affected by the decadal changes in P availability and recycling over the past 40 years. The changes in P dynamics on decadal time scales were not recorded in sediment profiles of total P or organic C/total P.

show abstract

The effect of oxygen availability on long‐distance electron transport in marine sediments

Burdorf

Malkin

Bjerg

et al. 2018

Limnology & Oceanography

View full text Add to dashboard Cite

Cable bacteria are long, multicellular, filamentous bacteria that can conduct electrons over centimeter distances in marine and freshwater sediments. Recent studies indicate that cable bacteria are widely present in many coastal environments, where they exert a major influence on the biogeochemistry of the sediment. Their energy metabolism can be based on the aerobic oxidation of sulfide, and hence to better understand their natural occurrence and distribution, we examined the growth and activity of cable bacteria in relation to bottom water oxygenation. To this end, we conducted laboratory sediment incubations at four different O2 levels in the overlying water (10%, 20%, 40%, and 100% air saturation). The abundance of cable bacteria was determined by fluorescence in situ hybridization, while their activity was assessed via microsensor profiling and geochemical pore‐water analysis. Cable bacteria did not develop in the 10% air saturation O2 incubation but were present and active at all higher O2 levels. These data show that microbial long‐distance electron transport can occur under a wide range of bottom water O2 concentrations. However, the growth rate was notably slower at lower oxygen concentrations, suggesting a reduced metabolic activity of the population when the O2 supply becomes restricted. Finally, in response to lower O2 levels, cable bacteria filaments appear to partially emerge out of the sediment and extend into the overlying water, thus likely enhancing their oxygen supply.

show abstract

Impact of cable bacteria on sedimentary iron and manganese dynamics in a seasonally-hypoxic marine basin

Cited by 78 publications

References 58 publications

Mn∕Ca intra- and inter-test variability in the benthic foraminifer <i>Ammonia tepida</i>

Mn∕Ca intra- and inter-test variability in the benthic foraminifer <i>Ammonia tepida</i>

Phosphorus Cycling and Burial in Sediments of a Seasonally Hypoxic Marine Basin

The effect of oxygen availability on long‐distance electron transport in marine sediments

Contact Info

Product

Resources

About

Impact of cable bacteria on sedimentary iron and manganese dynamics in a seasonally-hypoxic marine basin

Cited by 78 publications

References 58 publications

Mn∕Ca intra- and inter-test variability in the benthic foraminifer &lt;i&gt;Ammonia tepida&lt;/i&gt;

Mn∕Ca intra- and inter-test variability in the benthic foraminifer &lt;i&gt;Ammonia tepida&lt;/i&gt;

Phosphorus Cycling and Burial in Sediments of a Seasonally Hypoxic Marine Basin

The effect of oxygen availability on long‐distance electron transport in marine sediments

Contact Info

Product

Resources

About

Mn∕Ca intra- and inter-test variability in the benthic foraminifer <i>Ammonia tepida</i>

Mn∕Ca intra- and inter-test variability in the benthic foraminifer <i>Ammonia tepida</i>