Grain sizes retained by diatom biofilms during erosion on tidal flats linked to bed sediment texture

Garwood, Jessica C.; Hill, Paul S.; MacIntyre, Hugh L.; Law, Brent

doi:10.1016/j.csr.2015.05.004

Cited by 21 publications

(10 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Resuspended sediments with benthic carbonates could contribute to total carbon during extreme wind events. But, as the source of the benthic carbonate is likely to be shell and shell hash, it is very unlikely that these Journal of Geophysical Research: Oceans 10.1002/2016JC012275 size materials would be resuspended all the way to the surface during high winds [Garwood et al, 2015]. Thus, lacking any significant sources of particulate inorganic carbon, we refer to our particulate carbon data as POC.…”

Section: Field Observationsmentioning

confidence: 99%

Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

Lehrter

et al. 2017

JGR Oceans

View full text Add to dashboard Cite

Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long‐term POC observations and the complexity of coastal hydrodynamic and biogeochemical processes that influence POC sources and sinks. Using field observations and satellite ocean color products, we developed a new multiple regression algorithm to estimate POC on the Louisiana Continental Shelf (LCS) from satellite observations. The algorithm had reliable performance with mean relative error (MRE) of ∼40% and root mean square error (RMSE) of ∼50% for MODIS and SeaWiFS images for POC ranging between ∼80 and ∼1200 mg m−3, and showed similar performance for a large estuary (Mobile Bay). Substantial spatiotemporal variability in the satellite‐derived POC was observed on the LCS, with high POC found on the inner shelf (<10 m depth) and lower POC on the middle (10–50 m depth) and outer shelf (50–200 m depth), and with high POC found in winter (January–March) and lower POC in summer to fall (August–October). Correlation analysis between long‐term POC time series and several potential influencing factors indicated that river discharge played a dominant role in POC dynamics on the LCS, while wind and surface currents also affected POC spatial patterns on short time scales. This study adds another example where satellite data with carefully developed algorithms can greatly increase the spatial and temporal observations of important biogeochemical variables on continental shelf and estuaries.

show abstract

Section: Field Observationsmentioning

confidence: 99%

Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

Lehrter

et al. 2017

JGR Oceans

View full text Add to dashboard Cite

show abstract

“…Biofilms in intertidal sediments have been reported to form an adhesive coat on sand grains that acts as a binding agent capable of forming aggregates of diatoms, organics, and clay minerals (Kessarkar et al, 2010) and that is also responsible for fine particle entrapment in sand-dominated estuarine tidal flats (Garwood et al, 2015). In the presence of common divalent cations, such as Mg 2+ and Ca 2+ , that are present in estuarine waters, EPS biofilm fractions become water insoluble, tightly bound to sand grain surfaces, and resistant to degradation, increasing with depth in the top few millimeters of the sediment column (Stal, 2003;De Winder et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

“…Excreted EPS strands allow diatom movement in near-surface sediment, but they also anchor diatoms to sand grain surfaces. The strands detach from the diatom on movement and remain on mineral grain surfaces; this produces a web of bridging and coating mucus (biofilm) strands on grain mineral surfaces (Garwood et al, 2015;Higgins et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…Biofilms have been shown to play a fundamental role in sediment dynamics and the subsequent diagenesis of marginal marine sedimentary systems (Stal, 2003), affecting grain-size heterogeneity (Garwood et al, 2015), sediment stability (Vignaga et al, 2013), sediment transport, and bedform stability Schindler et al, 2015). Intertidal biofilms typically result from the secretion of extracellular polymeric substances (EPSs) (adhesive mucilage) by microphytobenthic (MPB) communities that are composed of algae (diatoms, euglenids, crysophyceans, dinoflagellates), cyanobacteria, and other photosynthetic bacteria (Jesus et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Biofilm origin of clay-coated sand grains

Wooldridge

Worden

Griffiths

et al. 2017

Geology

View full text Add to dashboard Cite

The presence of clay-sized particles and clay minerals in modern sands and ancient sandstones has long presented an interesting problem, because primary depositional processes tend to lead to physical separation of fine-and coarse-grained materials. Numerous processes have been invoked to explain the common presence of clay minerals in sandstones, including infiltration, the codeposition of flocculated muds, and bioturbation-induced sediment mixing. How and why clay minerals form as grain coats at the site of deposition remains uncertain, despite clay-coated sand grains being of paramount importance for subsequent diagenetic sandstone properties. We have identified a new biofilm mechanism that explains clay material attachment to sand grain surfaces that leads to the production of detrital clay coats. This study focuses on a modern estuary using a combination of field work, scanning electron microscopy, petrography, biomarker analysis, and Raman spectroscopy to provide evidence of the pivotal role that biofilms play in the formation of clay-coated sand grains. This study shows that within modern marginal marine systems, clay coats primarily result from adhesive biofilms. This bio-mineral interaction potentially revolutionizes the understanding of clay-coated sand grains and offers a first step to enhanced reservoir quality prediction in ancient and deeply buried sandstones.

show abstract

“…Microbial mats in Paso Seco are mainly formed by filamentous cyanobacteria and diatoms, where cyanobacteria provide mechanical strength derived from the linkage of trichomes with the sediment grains, and diatoms sheltered them at the top of the surface. Both cyanobacteria and diatoms contribute to the biostabilization by an upward migration during emersion by the excretion of EPS strands (Staats et al, 2000;Underwood & Paterson, 2003;Garwood et al, 2015). A typical mat fabric is formed in siliciclastic sediments by the active movement of cyanobacteria and diatoms.…”

Section: Interaction Of Microbially Colonized Sediments With Hydrodynmentioning

confidence: 99%

Geobiological model of ripple genesis and preservation in a heterolithic sedimentary sequence for a supratidal area

Cuadrado

2020

Sedimentology

View full text Add to dashboard Cite

This study documents the processes involved in forming flaser and wavy bedding governed by microbial activity in sediments. It focuses on a modern marginal‐tidal system providing evidence of the role that biofilms play in the stabilization of ripples and their potential preservation. A combination of detailed field work, analysis of water level records and microscopic petrographic inspection were used to reply to the question: how fine‐grained and coarse‐grained sediments can sequentially be deposited and preserved in a coastal environment. The hydraulic energy was measured by water level sensors recording flooding events that inundate the colonized tidal flat. Changing surface morphologies were monitored after storms, revealing the importance of biological processes in the preservation of ripples. A mud drape over ripples was observed several days after the undulated surface formation, known as a sinoidal sedimentary structure, which is a thin biofilm covering the ripples, caused by the presence of a microbial mat. Because bedforms are essential predictors of palaeoenvironmental reconstruction, interpretation in the geological record should take into consideration the important effect that colonized sediments have on the preservation of ripples. A geobiological model explains the flaser sedimentation, common in depositional coastal environments, suggesting that the hydrodynamic conditions may not be directly reflected by the grain size at the time of deposition. The study reveals that flaser sedimentation involves an interaction with benthic organisms, reflected by the sequence of microbial mats with sand ripple marks. A detailed description of heterolithic sequences shows that the presence of microbial activity can drive ripple preservation. This suggests that hydraulic interpretation of the sedimentary record based only on physical processes might be erroneous.

show abstract

Grain sizes retained by diatom biofilms during erosion on tidal flats linked to bed sediment texture

Cited by 21 publications

References 37 publications

Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

Biofilm origin of clay-coated sand grains

Geobiological model of ripple genesis and preservation in a heterolithic sedimentary sequence for a supratidal area

Contact Info

Product

Resources

About