Temporal variation in sediment erodibility and suspended sediment dynamics in the Dollard estuary

Kornman, B.A.; Deckere, E.M.G.T. de

doi:10.1144/gsl.sp.1998.139.01.19

Cited by 29 publications

(21 citation statements)

References 20 publications

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“…As a consequence of the low τ ce values, the bottom sediment has been less compacted and its water content is high because of frequent submergence beneath tidal water. Examples of τ ce b 0.2 N/m 2 have also been reported for the mudflats in the Ems/ Dollard estuary, the Netherlands (τ ce = 0.1 N/m 2 on average for soft deposits; Kornman, 1998), for the Skeffling mudflats in the Humber estuary, UK (τ ce = 0.18 N/m 2 ; Table 1 in Houwing, 1999), and for mudflats in Luoyuan Bay, Southeastern China (τ ce = 0.11-0.15 N/m 2 ; Wang, 2009). In the present study, the value of τ ce was slightly higher at the salt marsh site than at the mudflat site, probably because the higher elevation of the marsh site and its more frequent exposure to air resulted in a lower water content of the bottom sediment, although transpiration by marsh vegetation may also be partly responsible for dewatering at this site.…”

Section: Values Of τ Ce and τ CDmentioning

confidence: 69%

Relating accretion and erosion at an exposed tidal wetland to the bottom shear stress of combined current–wave action

et al. 2012

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Section: Values Of τ Ce and τ CDmentioning

confidence: 69%

Relating accretion and erosion at an exposed tidal wetland to the bottom shear stress of combined current–wave action

et al. 2012

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“…Rutgers van der Loeff and Boudreau 1997; Sohma et al 2001), but less importance is given to the biological processes that interact in this exchange. The erosive behaviour of erodability (Kornman and de Deckere 1998;Widdows et al 2000;Blanchard et al 2001).…”

Section: Introductionmentioning

confidence: 99%

Nereis diversicolor effect on the stability of cohesive intertidal sediments

2006

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The effect of the polychaete Nereis diversicolor on the stability of natural cohesive sediments was investigated in the laboratory. Three densities (450, 600 and 1200 ind m À2 ) of N. diversicolor were used. Sediment shear strength was measured using a cone penetrometer. Sediment erodability was assessed using an annular flume (current velocities from 5 to 55 cm s À1 ) in which flow velocity was increased incrementally, and water sampled to quantify suspended material in order to derive critical erosion velocity and erosion rates. At low current velocities (<25 cm s À1 ), we found N. diversicolor to have a stabilising effect, reflected by an increase of up to 20% in the critical erosion velocity. This is related to an enhancement of $50% in shear strength, due probably to gallery building activities, responsible for the promotion of lateral compaction, an increase in the area of the sediment-water interface, and enhanced microphytobenthos production. Once the sediment began to erode, the stabilising effect of N. diversicolor reverses, leading to an increase of up to 40% in eroded matter due to compaction, which resulted in the erosion of larger aggregates. The balance between the effect of N. diversicolor on herbivory and microphytobenthos production due to the presence of galleries is discussed. Our results indicate that neither chlorophyll a, nor shear strength nor critical erosion velocity are good indicators of erodability. This underlines the need to include biogeochemical processes in any realistic sediment transport model.

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“…EPS-production may also be controlled by nutrient availability, for instance when the organisms grow under unbalanced conditions (Ruddy et al 1998), a situation likely to occur in intertidal environments (Flothmann & Werner 1992). The presence of diatom biofilms increases the stability of the sediment surface (Kornman & de Deckere 1998, Paterson 1989) and can have a profound effect on the morphodynamics of mudflats (Dyer 1998. Through the excretion of EPS, diatoms are responsible for a considerable input of high-quality organic carbon into the sediment that may be utilized as a food source for heterotrophic consumers (King 1986, van Duyl et al 1999.…”

Section: Introductionmentioning

confidence: 99%

Short-term dynamics in microphytobenthos distribution and associated extracellular carbohydrates in surface sediments of an intertidal mudflat

Brouwer¹,

Stal²

2001

Mar. Ecol. Prog. Ser.

147

123

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Two field studies were conducted to study the in situ net production of extracellular carbohydrates and the distribution of benthic diatoms over a period of 24 h per study. A comparison was made between a situation where a clear surface biofilm of diatoms had developed and a situation where this was not the case. Vertical profiles were made by sampling the top 2 mm of the sediment at depth intervals of 0.2 mm using the 'cryolander' technique. In the presence of a biofilm, diatom distribution showed a consistent pattern when the sediment was emersed. In the light, most of the diatoms were present in the top 0.2 mm while in the dark, diatoms were homogeneously distributed in the upper 2 mm of the sediment. When a biofilm was absent, no clear patterns were observed. Extracellular carbohydrates were extracted from the sediment and separated in 2 operationally defined fractions (colloidal and EDTA-extractable). The 2 carbohydrate fractions showed a different dynamic behaviour. The colloidal carbohydrate fraction was highly variable while the EDTAextractable fraction behaved more conservatively. Only in the light and in the presence of a diatom biofilm, was production of extracellular carbohydrates observed. The maximum rate of chlorophyllnormalized production of extracellular carbohydrates, expressed in glucose equivalents (g g -1), amounted to 20 h -1 in the upper 0.2 mm. The molecular size distribution of both carbohydrate fractions was similar. The monosaccharide composition was also similar, except that the EDTAextractable fraction contained a higher percentage of uronic acids. Carbohydrates produced during tidal emersion were rich in glucose and were rapidly turned over.

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Temporal variation in sediment erodibility and suspended sediment dynamics in the Dollard estuary

Abstract: The influence of biological activity on sediment erodibility was studied in the the sediment surface (Vos et al. 1988). The KORNMAN, B. A. & DE DECKERE, E. M. G. T. 1998. Temporal variation in sediment erodibility and suspended sediment dynamics in the Dollard estuary.

Cited by 29 publications

References 20 publications

Relating accretion and erosion at an exposed tidal wetland to the bottom shear stress of combined current–wave action

Relating accretion and erosion at an exposed tidal wetland to the bottom shear stress of combined current–wave action

Nereis diversicolor effect on the stability of cohesive intertidal sediments

Short-term dynamics in microphytobenthos distribution and associated extracellular carbohydrates in surface sediments of an intertidal mudflat

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