The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Craig J Plante - One of the best experts on this subject based on the ideXlab platform.
-
influence of the facultative Deposit Feeder mesochaetopterus taylori on microbial community structure of sediments
Bulletin of Marine Science, 2011Co-Authors: Craig J Plante, Thomas O BusbyAbstract:Field observations of the polychaete Mesochaetopterus taylori Potts, 1914, indicated facultative Deposit feeding was elicited by tidal variations. Two distinct types of M. taylori egesta were observed, usually as part of the same fecal coil: mucus-packaged brown pellets, and gray coils that resembled surrounding sediment Deposits in color and texture. Our goal was to compare bacterial and microalgal communities from brown and gray egesta, surface sediments, deep (-5 cm) sediments, and the benthic nepheloid layer collected from sandflats in North Inlet, South Carolina. Bacterial and diatom assemblages were compared through denaturing gradient gel electrophoresis fingerprinting. Epifluorescence microscopy was used to enumerate bacteria and fluorometric quantification of chlorophyll a was employed as a proxy for microalgal biomass. Microbiological evidence, combined with field observations and granulometric data, confirmed that gray coils were derived primarily from subsurface sediments during Deposit feeding at low tide, with a smaller contribution from surface (top 2 mm) Deposits. Microbiota in brown egesta showed overlap with microbial assemblages in both the nepheloid layer and uppermost sediment layers at low tide. Microalgal biomass was removed during gut transit; however, the quantitative effect on bacteria was less clear due to selective feeding, digestion, and potential growth within the gut. Although brown and gray coils were distinct, there was a clear "gut signature" such that egesta had microbiological similarities regardless of provenance. Thus, the net effect of M. taylori on sedimentary microbial structure is substantial, as it both digestively removes specific microbiota and reduces diversity while Deposit feeding, yet introduces species to sediments by pelletizing suspended particulates.
-
Recolonization and cues for bacterial migration into 'mock' Deposit-Feeder fecal casts
Aquatic Microbial Ecology, 2003Co-Authors: Craig J Plante, Stephanie StinsonAbstract:Despite the importance of sedimentary bacteria to the cycling of organic matter in the marine environment, fundamental knowledge concerning the determinants of community structure is lacking. Roles of equilibrium processes, such as predation and competition, have generally been found to be of little importance, whereas the role of disturbance in structuring microbial communities has been less explored. Disturbance associated with invertebrate ingestion can reduce bacterial biomass and alter metabolic activities and compositions of bacterial assemblages in marine sediments. The first objective of the research presented here was to determine the mechanisms by which bacterial assemblages recover following their ingestion by Deposit Feeders. In exposed inter- tidal sediments, microbial recovery could occur due to regrowth of bacterial populations surviving gut passage, or to migration from adjacent sediments. We used field manipulative experiments to exclude either regrowth, with the use of bacteria-free 'mock' fecal coils, or migration, by isolating coils from surrounding sediments on polystyrene 'latrines.' A second goal was to test whether components of Deposit-Feeder egesta served as cues for bacterial colonization. Supernatant fluids from the egesta of 4 Deposit-feeding species were added to the artificial fecal coils. We then followed the numerical recovery of active and total bacteria in coils through time using CTC (5-cyano-2, 3- ditoyl tetrazolium chloride) and DAPI stains coupled with epifluorescence microscopy. Our findings indicate that (1) recovery was dominated by immigration, as no recolonization was observed in coils isolated from adjacent sediments, (2) components of 2 of the 4 Deposit-feeding species' egesta inhib- ited bacterial recolonization, and (3) although recovery was observed in coils with added fecal com- ponents of the remaining 2 species, in no case was recolonization stimulated relative to seawater addition. The last finding suggests that nutritional provision is not a significant impetus for recolo- nization of sediment patches disturbed by Deposit feeding. Competitor-free space and vertical migra- tions of diatoms in intertidal sediments are discussed as alternative cues for bacterial recolonization of these disturbed patches.
-
Bacterial recolonization of Deposit-Feeder egesta: In situ regrowth or immigration?
Limnology and Oceanography, 2001Co-Authors: Craig J Plante, Susan B. WildeAbstract:The related processes of disturbance, recolonization, and succession can play major roles in structuring communities and in generating spatial heterogeneity. Nonequilibrium processes have been little studied with respect to microbial community dynamics. Here we report experimental efforts to identify the mechanisms of recolonization of egesta employing two intertidal Deposit Feeders, Balanoglossus aurantiacus and Nereis succinea. Using direct microscopic counts and Biolog plates, we compared the quantitative and qualitative patterns of recovery in egesta isolated from underlying sediments on “latrines” to recolonization in naturally incubated fecal casts. Significant recovery over the 2-h observation periods was never seen on latrines. Rapid recovery in metabolic potential was observed in the naturally incubated fecal casts of both animal species. Likewise, a rapid numerical recovery was seen in the egesta of N. succinea casts on sediments. In contrast, no numerical recovery was evident in any fecal casts of B. aurantiacus over 2 h, regardless of treatment. For these two species, recolonization appears to be dominated by migration of bacteria from underlying sediments as opposed to repopulation by survivors of ingestion. These findings indicate that renewal of available (digestible) microbial resources to Deposit Feeders is more rapid than would be predicted if regrowth was the dominant process of recolonization. Furthermore, because recovery time is short relative to the interval between disturbances, Deposit feeding is unlikely to play a major role in structuring benthic microbial communities.
-
Feeding and bacteriolytic responses of the Deposit-Feeder Abarenicola pacifica (Polychaeta: Arenicolidae) to changes in temperature and sediment food concentration
Marine Biology, 2000Co-Authors: Sabrina N. Hymel, Craig J PlanteAbstract:Deposit-Feeders can respond to seasonal fluctuations in food concentration both functionally (e.g. by adjusting feeding rates) and physiologically (e.g. by changing the concentration of bacteriolytic agents in gut fluids). Laboratory feeding experiments were carried out (11 to 21 July 1997) with the arenicolid polychaete worm Abarenicola pacifica (Healy and Wells). Objectives were to test for separate and interactive effects of sediment food concentration and temperature (6, 11, and 16 °C) on Deposit-Feeder functional (feeding rates) and physiological (bacteriolytic activity of gut fluids) responses. Food concentration was varied experimentally using sieved (1 mm) natural sediments (Md φ=2.00; 0.6% organic) mixed with combusted (500 °C, 8 h) sediments for final concentrations of 25, 50, and 100% natural sediment. Sediment food quality was measured as: (1) bioavailable amino acids (EHAA), (2) chlorophyll a (chl a), and (3) bacterial abundance. Feeding rates were inferred from egestion rates (ER, g h−1) and analyzed with respect to worm size. Bacteriolytic activity of midgut fluids was assayed turbidimetrically against two bacterial isolates, after worms had fed on experimental sediments for 15 d. Temperature and food concentration both significantly affected feeding rates, with maxima occurring at 50 and 100% natural sediment mixtures, and at high (16 °C) temperature. ER was positively, but not significantly correlated with EHAA and chl a; a positive, significant correlation was detected between ER and sediment bacterial abundance. Overall, functional responses agreed with earlier compensatory intake models for Deposit-Feeders. However, the size and direction of these responses was temperature-sensitive, suggesting that these models need to be adjusted for changes in absorption rates. No effects of ambient temperature or food concentration on bacteriolytic rates were observed, possibly due to compensatory mechanisms or the presence of multiple bacteriolytic agents in gut fluids.
-
role of bacterial exopolymeric capsules in protection from Deposit Feeder digestion
Aquatic Microbial Ecology, 2000Co-Authors: Craig J PlanteAbstract:Digestion of diverse strains of sedimentary bacteria by Deposit Feeders occurs at markedly disparate efficiencies, thus altering the composition of bacteria in feces and surrounding sediments. In an earlier study. I explored 2 potential mechanisms for resistance to lysis by digestive fluids of Arenicola marina (Polychaeta: Arenicolidae), cell wall ultrastructure and exopolymeric capsules. This correlative study revealed no relationship between encapsulation and lytic susceptibility across strains, whereas cell wall type (Gram-positive or -negative) was not independent of susceptibility, with Grampositive strains always resistant. In this study, I tested the importance of capsules within strains by comparing susceptibility after manipulation of capsule quantity using 2 techniques: (1) mechanical removal of capsules, and (2) harvest of cells through various growth phases as capsule thickness changes. We found that resistant strains remained resistant regardless of capsule quantity. Two of 3 strains that normally exhlbit some susceptibility to lysis, Pseudornonas atlanhca and SS-1, however, increased in their susceptibility with mechanical removal of capsules. Further, capsule quantity per cell varied throughout the growth cycle for these 2 strains, and lytic susceptibility varied concomitantly during logarithmic phase, in an inverse manner. Susceptibility of the third susceptible strain, IQ-2, remained unaltered with removal of capsules. This strain also exhibited dramatic change in capsule thickness with culture age, but lytic susceptibility was positively correlated to capsule mass per cell, in marked contrast to P. atlantica and SS-1. Although capsules can reduce the susceptibility of some bacterial strains, their presence does not convey protection from digestion in all strains, nor is encapsulation the only mechanism of resistance. One common feature for all these strains was that susceptibility to lysis declined after cultures reached stationary phase. Consequently, Deposit feeding may impact physiological as well as taxonomic structure of bacterial assemblages in sediments.
Lawrence M Mayer - One of the best experts on this subject based on the ideXlab platform.
-
digestive bioavailability to a Deposit Feeder arenicola marina of polycyclic aromatic hydrocarbons associated with anthropogenic particles
Environmental Toxicology and Chemistry, 2004Co-Authors: Ian M Voparil, Lawrence M Mayer, Robert M Burgess, Rex Tien, Mark G Cantwell, Stephen A RybaAbstract:Marine sediments around urban areas serve as catch basins for anthropogenic particles containing polycyclic aromatic hydrocarbons (PAHs). Using incubations with gut fluids extracted from a Deposit-feeding polychaete ( Arenicola marina), we determined the digestive bioavailability of PAHs from fly ashes, coal dusts, diesel soots, tire tread materials, and urban particulates. We found that gut fluids solubilize significant concentrations of PAHs from two tire treads, two diesel soots, and the urban particulates. However, PAHs in fly ashes and coal dusts were not available to the digestive agents in gut fluid. Potential digestive exposure to PAHs is much greater than that predicted to be available from these materials using equilibrium partitioning theory (EqP). Amending an already-contaminated sediment with fly ash decreased phenanthrene solubilization by gut fluid. In contrast, addition of tire tread to the sediment resulted in increased solubilization of four PAHs by gut fluid. Therefore, addition of certain types of anthropogenic particles to sediments may result in an increase in bioavailable PAHs rather than a net decrease, as predicted by EqP. Difficulty in predicting the amount of change due to amendment may be due to interactions occurring among the mixture of compounds solubilized by gut fluid.
-
digestive bioavailability to a Deposit Feeder arenicola marina of polycyclic aromatic hydrocarbons associated with anthropogenic particles
Environmental Toxicology and Chemistry, 2004Co-Authors: Ian M Voparil, Lawrence M Mayer, Robert M Burgess, Rex Tien, Mark G Cantwell, Stephen A RybaAbstract:Marine sediments around urban areas serve as catch basins for anthropogenic particles containing polycyclic aromatic hydrocarbons (PAHs). Using incubations with gut fluids extracted from a Deposit-feeding polychaete (Arenicola marina), we determined the digestive bioavailability of PAHs from fly ashes, coal dusts, diesel soots, tire tread materials, and urban particulates. We found that gut fluids solubilize significant concentrations of PAHs from two tire treads, two diesel soots, and the urban particulates. However, PAHs in fly ashes and coal dusts were not available to the digestive agents in gut fluid. Potential digestive exposure to PAHs is much greater than that predicted to be available from these materials using equilibrium partitioning theory (EqP). Amending an already-contaminated sediment with fly ash decreased phenanthrene solubilization by gut fluid. In contrast, addition of tire tread to the sediment resulted in increased solubilization of four PAHs by gut fluid. Therefore, addition of certain types of anthropogenic particles to sediments may result in an increase in bioavailable PAHs rather than a net decrease, as predicted by EqP. Difficulty in predicting the amount of change due to amendment may be due to interactions occurring among the mixture of compounds solubilized by gut fluid.
-
effect of extraction conditions on trace element solubilization in Deposit Feeder digestive fluid
Environmental Toxicology and Chemistry, 2004Co-Authors: Donald P Weston, Jeffrey R Judd, Lawrence M MayerAbstract:In vitro extraction of sediments using digestive fluid of Deposit-feeding invertebrates has been advocated as a measure of in vivo bioavailability, but the standard procedure used for the extractions alters fluid properties relative to in vivo conditions. In vivo fluid properties (redox potential [Eh], pH, dissolved oxygen) were measured in the gut of the polychaete Arenicola brasiliensis, and then the effects of gut evacuation, elevated temperature, and atmospheric exposure on these properties and/or metal and metalloid extraction capability of the fluid was assessed. The midgut of A. brasiliensis has an electropositive Eh of about +170 to +230 mV, a neutral pH, and little or no dissolved oxygen. Exposure to the atmosphere during in vitro extraction increased gut fluid oxygen content and affected the ability of the fluid to extract some trace elements from sediment particles, particularly Pb, Ni, Cu, Mn, and As. Even for these substances, however, the effects of oxygen exposure on extractability by gut fluid typically were small (<2-fold difference in amount extracted). For Cr, Hg, Se, Cd, Fe, and Zn, the effects of oxygen exposure usually were minor and inconsistent in direction. Maintaining anaerobic conditions during in vitro contaminant extractions is necessary when the experimental objective is to mimic accurately in vivo conditions and predict trace element extraction in the gut. If using metal extractability as a relative measure for sediment risk assessment purposes, a high degree of accuracy may not be required, and aerobic in vitro extractions could be suitable and produce only minor errors in extractability relative to in vivo conditions.
-
commercially available chemicals that mimic a Deposit Feeder s arenicola marina digestive solubilization of lipids
Environmental Science & Technology, 2004Co-Authors: Ian M Voparil, Lawrence M MayerAbstract:To develop a simple and cost-effective bioavailability test for sediment-bound contaminants, the solubilization strengths of mixtures of four commercially available surfactants and four proteins were compared to that of digestive fluids from a Deposit-feeding benthic polychaete Arenicola marina. Initial tests indicated that sodium taurocholate, a vertebrate bile salt, was the most accurate mimic of A. marina gut fluids' solubilization of individual polycyclic aromatic hydrocarbons (PAH). Further testing with nutritional lipids and other hydrophobic contaminants confirmed the similarities of these fluids. Bovine serum albumin (BSA) solubilization of PAH was the most efficient of all the proteins tested. A cocktail of sodium taurocholate and BSA was compared to A. marina's solubilization of 12 PAH from four different contaminated sediments (from Boston, Charleston, Jacksonville, and San Diego harbors). The two solutions released most PAH to similar extents; 40 of 48 PAH−sediment combinations were released a...
-
commercially available chemicals that mimic a Deposit Feeder s arenicola marina digestive solubilization of lipids
Environmental Science & Technology, 2004Co-Authors: Ian M Voparil, Lawrence M MayerAbstract:To develop a simple and cost-effective bioavailability test for sediment-bound contaminants, the solubilization strengths of mixtures of four commercially available surfactants and four proteins were compared to that of digestive fluids from a Deposit-feeding benthic polychaete Arenicola marina. Initial tests indicated that sodium taurocholate, a vertebrate bile salt, was the most accurate mimic of A. marina gut fluids' solubilization of individual polycyclic aromatic hydrocarbons (PAH). Further testing with nutritional lipids and other hydrophobic contaminants confirmed the similarities of these fluids. Bovine serum albumin (BSA) solubilization of PAH was the most efficient of all the proteins tested. A cocktail of sodium taurocholate and BSA was compared to A. marina's solubilization of 12 PAH from four different contaminated sediments (from Boston, Charleston, Jacksonville, and San Diego harbors). The two solutions released most PAH to similar extents; 40 of 48 PAH-sediment combinations were released at amounts within a factor of 2 in cocktail and gut fluid solutions. Therefore, the cocktail may serve as a surrogate for real gut fluids and allow easier adoption of the in vitro incubation approach to bioavailability testing.
Paul F. Kingston - One of the best experts on this subject based on the ideXlab platform.
-
observations on the effects of barite on the gill tissues of the suspension Feeder cerastoderma edule linne and the Deposit Feeder macoma balthica linne
Marine Pollution Bulletin, 2001Co-Authors: M J Barlow, Paul F. KingstonAbstract:Barite, an important component of offshore drilling muds, is shown to adversely affect the ctenidia of the suspension feeding bivalve, Cerastoderma edule and the Deposit Feeder, Macoma balthica. SEM observations showed that exposure to barite caused cilia to shorten and coagulate, and, in some extreme cases, cause the disintegration of the gill structure itself. Using a simple ciliary condition index (CCI) the impact of the barite was quantified and damage rates expressed. The bivalves were treated with daily doses of 1, 2, and 3-mm depth equivalents of barite. In all treatments significant damage to the gills was recorded although, in the case of the 1-mm dose rate, this did not occur for 4 days. In the other two treatments, damage was apparent within a day of exposure with 100% mortality occurring within 12 days. Macoma balthica appeared slightly more tolerant of exposure to barite than C. edule.
-
observations on the effects of barite on the gill tissues of the suspension Feeder cerastoderma edule linne and the Deposit Feeder macoma balthica linne
Marine Pollution Bulletin, 2001Co-Authors: M J Barlow, Paul F. KingstonAbstract:Barite, an important component of offshore drilling muds, is shown to adversely affect the ctenidia of the suspension feeding bivalve, Cerastoderma edule and the Deposit Feeder, Macoma balthica. SEM observations showed that exposure to barite caused cilia to shorten and coagulate, and, in some extreme cases, cause the disintegration of the gill structure itself. Using a simple ciliary condition index (CCI) the impact of the barite was quantified and damage rates expressed. The bivalves were treated with daily doses of 1, 2, and 3-mm depth equivalents of barite. In all treatments significant damage to the gills was recorded although, in the case of the 1-mm dose rate, this did not occur for 4 days. In the other two treatments, damage was apparent within a day of exposure with 100% mortality occurring within 12 days. Macoma balthica appeared slightly more tolerant of exposure to barite than C. edule.
Nathalie Niquil - One of the best experts on this subject based on the ideXlab platform.
-
Influence of environment factors on bacterial ingestion rate of the Deposit-Feeder Hydrobia ulvae and comparison with meiofauna
Journal of Sea Research, 2008Co-Authors: Pierre-yves Pascal, Christine Dupuy, Pierre Richard, Anne-gaelle Haubois, Nathalie NiquilAbstract:Deposit Feeders are able to process a considerable volume of sediment, containing large 9 quantities of associated bacteria. However, conclusions concerning the trophic role played by 10 benthic bacteria in marine sediments are still not fully elucidated. This study deals with 11 bacterivory by the gastropod Hydrobia ulvae, one of the most abundant Deposit-feeding 12 species in intertidal mudflats in Western Europe. Ingestion rates of bacteria were determined 13 during grazing experiments using 15 N pre-enriched bacteria. Grazing experiments were 14 performed in order to measure effects of abiotic (temperature, salinity and luminosity) and 15 biotic (bacterial and algal abundances) factors on ingestion rates of bacteria by H. ulvae of an 16 intertidal mudflat (Brouage, Marennes-Oléron, France). The mean ingestion rate of bacteria 17 by H. ulvae was 1149 ngC ind-1 h-1. The general trend showed a temperature effect with an 18 optimum around 30°C, and the assimilation rate was significantly lower at 5°C. Bacterial 19 assimilation did not significantly differ between salinity 18 and salinity 31. Ingestion was the 20 same in light and in dark conditions. Results were compared with those of other grazing 21 experiments conducted simultaneously in similar conditions with two other grazers with 22 different size and feeding modes: the foraminifera Ammonia tepida and a nematode 23 community from the superficial sediment of the Brouage mudflat. Hydrobia ulvae and 24 nematodes presented a feeding behavior less influenced by environmental changes than A. tepida. Hydrobia ulvae ingested bacteria at a higher rate than smaller meiofaunal grazers and seemed to have a lower ability to selectively ingest diatoms than meiofaunal grazers.
-
Influence of environment factors on bacterial ingestion rate of the Deposit-Feeder Hydrobia ulvae and comparison with meiofauna
Journal of Sea Research, 2008Co-Authors: Pierre-yves Pascal, Christine Dupuy, Pierre Richard, Anne-gaelle Haubois, Nathalie NiquilAbstract:Deposit Feeders are able to process a considerable volume of sediment, containing large quantities of associated bacteria. However, conclusions concerning the trophic role played by benthic bacteria in marine sediments are still not fully elucidated. This study deals with bacterivory by the gastropod Hydrobia ulvae, one of the most abundant Deposit-feeding species in intertidal mudflats in Western Europe. Ingestion rates of bacteria were determined during grazing experiments using 15N pre-enriched bacteria. Grazing experiments were performed in order to measure effects of abiotic (temperature, salinity and luminosity) and biotic (bacterial and algal abundances) factors on ingestion rates of bacteria by H. ulvae of an intertidal mudflat (Brouage, Marennes-Oleron, France). The mean ingestion rate of bacteria by H. ulvae was 1149 ng C ind− 1 h− 1. The general trend showed a temperature effect with an optimum around 30 °C, and the assimilation rate was significantly lower at 5 °C. Bacterial assimilation did not significantly differ between salinity 18 and salinity 31. Ingestion was the same in light and in dark conditions. Results were compared with those of other grazing experiments conducted simultaneously in similar conditions with two other grazers with different size and feeding modes: the foraminifera Ammonia tepida and a nematode community from the superficial sediment of the Brouage mudflat. H. ulvae and nematodes presented a feeding behavior less influenced by environmental changes than A. tepida. H. ulvae ingested bacteria at a higher rate than smaller meiofaunal grazers and seemed to have a lower ability to selectively ingest diatoms than meiofaunal grazers.
Sébastien Lefebvre - One of the best experts on this subject based on the ideXlab platform.
-
The Comparison of δ^13C Values of a Deposit- and a Suspension-Feeder Bio-Indicates Benthic vs. Pelagic Couplings and Trophic Status in Contrasted Coastal Ecosystems
Estuaries and Coasts, 2016Co-Authors: Sylvie Marylène Gaudron, Karine Grangeré, Sébastien LefebvreAbstract:δ^13C and δ^15N values of two generalists primary consumers, a strict Deposit-Feeder polychaete ( Arenicola marina ), and a strict suspension-Feeder bivalve ( Crassostrea gigas ), were investigated to typify the trophic functioning of two contrasted marine coastal ecosystems (eutrophic and mesotrophic, east and west Cotentin peninsula, respectively, English Channel, Normandy, France). On average, δ^13C and δ^15N values of lugworms mirrored those of sediment organic matter (SOM), whereas δ^13C and δ^15N of oysters mirrored those of suspended particulate organic matter (SPOM). δ^13C values of the two species displayed significant differences on the west coast (mesotrophic) contrary to the east coast (eutrophic; significant interactions). δ^15N values differed only between sites and not between species. Diet of A. marina relied exclusively on microphytobenthos (MPB) and detritus of macroalgae (ULV) on the mesotrophic coast, whereas diet of C. gigas relied mainly on SPOM. Conversely, on the eutrophic ecosystem (the east coast), both species displayed the same diet, which was a mixture of pelagic sources (SPOM), benthic sources (MPB and ULV) and to a lesser extent riverine particulate organic matter (rPOM). These results were explained by the intensity of benthic vs. pelagic couplings (i.e. benthic-pelagic and pelagic-benthic) which differed in the two ecosystems. Low trophic coupling occurred on the mesotrophic (west) coast, whereas benthic-pelagic (SOM resuspension) and pelagic-benthic (settling of SPOM such as phytoplankton blooms) couplings were typified on the eutrophic (east) coast. This higher particulate organic matter (POM) pelagic-benthic coupling on the east coast was probably enhanced by nutrient enrichment caused by eutrophication. Comparison of δ^13C ratios of both the strict Deposit-Feeder (e.g. A. marina ) and the strict suspension-Feeder (e.g. C. gigas ) was then proposed as a bio-indicator of the trophic status and of POM benthic vs. pelagic couplings of soft-bottom coastal ecosystems.
-
Modelling the effects of macrofauna on sediment transport and bed elevation: application over a cross-shore mudflat profile and model validation
Estuarine Coastal and Shelf Science, 2012Co-Authors: Orvain Francis, Pierre Le Hir, Pierre-guy Sauriau, Sébastien LefebvreAbstract:The effects of 2 functional groups of bioturbators have been predicted in terms of long-term impact on erodability: (1) one superficial mobile Deposit-Feeder, the gastropod Hydrobia ulvae; and (2) one endobenthic Deposit-Feeder, the bivalve Scrobicularia plana. Different scenarios of morphodynamical cross-shore 1DH/1DV model were performed to simulate the equilibrium profile of an intertidal mudflat under tide and wave forcings. This process-based model for erosion is able to simulate multiphasic sequential resuspension, by discriminating various erosion behaviour like benthos-generated fluff-layer erosion (BGFL) and general bed loosening and burrowing activity in deep layers. The results were analysed and compared to examine the long-term effect of macrofauna after 14 years. It reveals that the impact of the bivalve S. plana is very significant after only 4 years of simulation while the effect of the gastropod H. ulvae is negligible in terms of sediment transport even after 14 years. More generally, this reveals the strong impact of stationary endobenthic bioturbators that induces a high downward shift of the upper shore while the effects of superficial motile bioturbators remain very low. This impact is mainly due to the effect of endobenthic species in deep layers associated to burrowing activities and their consequences on the bed erosion, but the production of a fluff layer by surface grazer like H. ulvae at the sediment surface can be neglected. The importance of macrofauna mediation of bed erodability is discussed in this study by comparing the activities of the two functional groups of bioturbation on the general functioning of intertidal mudflats. The model outcomes (transferred in a 1DV framework) were in close agreement with the measured results of flume data at 3 different bathymetric levels of the mudflat over the cross-shore profile. This validation step revealed that model of sediment transport under influence of biota effects does not need further refinements at the upper shore where S. plana dominates the species assemblage, whereas there is still a need to include further formulations of biota effects to simulate the erosion experimental results at the lower shores where other molluscs and Annelids significantly contribute to the species assemblage.