@article {7088, title = {Quantitative food web modeling unravels the importance of the microphytobenthos-meiofauna pathway for a high trophic transfer by meiofauna in soft-bottom intertidal food webs.}, journal = {Ecological Modelling}, volume = {430}, year = {2020}, abstract = {Meiofauna are known to have an important role on many ecological processes, although, their role in food web dynamics is often poorly understood, partially as they have been an overlooked and under sampled organism group. Here, we used quantitative food web modeling to evaluate the trophic relationship between meiofauna and their food sources and how meiofauna can mediate the carbon flow to higher trophic levels in five contrasting soft-bottom intertidal habitats (including seagrass beds, mudflats and sandflats). Carbon flow networks were constructed using the linear inverse model-Markov chain Monte Carlo technique, with increased resolution of the meiofauna compartments (i.e. biomass and feeding ecology of the different trophic groups of meiofauna) compared to most previous modeling studies. These models highlighted that the flows between the highly productive microphytobenthos and the meiofauna compartments play an important role in transferring carbon to the higher trophic levels, typically more efficiently so than macrofauna. The pathway from microphytobenthos to meiofauna represented the largest flow in all habitats and resulted in high production of meiofauna independent of habitat. All trophic groups of meiofauna, except for selective deposit feeders, had a very high dependency on microphytobenthos. Selective deposit feeders relied instead on a wider range of food sources, with varying contributions of bacteria, microphytobenthos and sediment organic matter. Ecological network analyses (e.g. cycling, throughput and ascendency) of the modeled systems highlighted the close positive relationship between the food web efficiency and the assimilation of high-quality food sources by primary consumers, e.g. meiofauna and macrofauna. Large proportions of these flows can be attributed to trophic groups of meiofauna. The sensitivity of the network properties to the representation of meiofauna in the models leads to recommending a greater attention in ecological data monitoring and integrating meiofauna into food web models. {\textcopyright} 2020 Elsevier B.V.}, keywords = {Carbon, Carbon flow networks, deposit feeder, Deposits, Ecological network analysis, Ecological process, Ecosystems, Feeding, Feeding ecology, food web, Food web model, intertidal community, intertidal habitats, Inverse problems, linear inverse model, Linear inverse models, Markov chain Monte Carlo techniques, Markov chains, Meiofauna, Microphytobenthos, Monte Carlo methods, Phytobenthos, quantitative analysis, Sediment organic matters, soft-bottom environment, stable isotope mixing models, trophic level, Trophic relationships, Trophic structure}, issn = {03043800 (ISSN)}, doi = {10.1016/j.ecolmodel.2020.109129}, author = {van der Heijden, L.H. and Nathalie Niquil and Haraldsson, M. and Asmus, R.M. and Pacella, S.R. and Graeve, M. and Rzeznik-Orignac, J. and Asmus, H. and Saint-B{\'e}at, B. and Lebreton, B.} } @article {6668, title = {Modelling the functioning of a coupled microphytobenthic-EPS-bacterial system in intertidal mudflats}, journal = {Marine Environmental Research}, volume = {150}, year = {2019}, abstract = {A mechanistic and biogeochemical model was developed to analyze the interactions between microphytobenthos (MPB), bacteria and nutrients in a tidal system. Behavioral vertical migration was hypothesized as being controlled by exogenous factors (tide and light) but also by endogenous factors (carbon and nitrogen requirements). The secretion of Extracellular Polymeric Substances (EPS) during photosynthesis (overflow metabolism) and migration of diatoms was also formulated. Similarities in MPB dynamics between observations and simulations support the assumption that carbon and nitrogen ratios are additional key processes behind the vertical migration of diatoms in the sediment. The model satisfactorily reproduced the three growth phases of the MPB development observed in a mesocosm (the lag phase, the logarithmic growth, and the plateau). Besides, nutrient availability, which could be induced by faunal bioturbation, significantly determined the extent of MPB biomass and development. The plateau phase observed in the last days of simulations appeared to be attributed to a nutrient depletion in the system, emphasizing the importance of nutrient availability. The model, although improvable especially on the formulation of the EPS excretion and bacteria development, already updated understanding of several aspects of benthic-system functioning during experimental conditions. {\textcopyright} 2019 Elsevier Ltd}, keywords = {Bacillariophyta, bacteria, Bacteria (microorganisms), bacterial growth, bacterium, Biogeochemical modeling, biogeochemistry, Biomass, Carbon, Carbon and nitrogen, Carbon and nitrogen ratios, Diatom, diel vertical migration, exopolymer, Experimental conditions, Extracellular polymeric substances, intertidal environment, intertidal zone, light, mesocosm, microbial community, Microphytobenthos, Migration, modeling, mudflat, Nitrogen, nonhuman, Nutrient availability, Nutrients, nutritional requirement, organic carbon, organismal interaction, Photosynthesis, Phytobenthos, Phytoplankton, polymer, Review, simulation, tide, vertical migration}, issn = {01411136}, doi = {10.1016/j.marenvres.2019.104754}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0141113619300704}, author = {Rakotomalala, C and Katell Guizien and Karine Granger{\'e} and S{\'e}bastien Lefebvre and Christine Dupuy and Francis Orvain} } @article {6667, title = {Dynamics of particulate organic matter composition in coastal systems: A spatio-temporal study at multi-systems scale}, journal = {Progress in Oceanography}, volume = {156}, year = {2017}, pages = {221-239}, abstract = {In coastal systems, the multiplicity of sources fueling the pool of particulate organic matter (POM) leads to divergent estimations of POM composition. Eleven systems (two littoral systems, eight embayments and semi-enclosed systems and one estuary) distributed along the three maritime fa{\c c}ades of France were studied for two to eight years in order to quantify the relative contribution of organic matter sources to the surface-water POM pool in coastal systems. This study was based on carbon and nitrogen elemental and isotopic ratios, used for running mixing models. The POM of the estuary is dominated by terrestrial material (93\% on average), whereas the POM of the other systems is dominated by phytoplankton (84\% on average). Nevertheless, for the latter systems, the POM composition varies in space, with (1) systems where POM is highly composed of phytoplankton (>=93\%), (2) systems characterized by a non-negligible contribution of benthic (8{\textendash}19\%) and/or river (7{\textendash}19\%) POM sources, and (3) the Mediterranean systems characterized by the contribution of diazotroph organisms (ca. 14\%). A continent-to-ocean gradient of river and/or benthic POM contribution is observed. Finally, time series reveal (1) seasonal variations of POM composition, (2) differences in seasonality between systems, and (3) an inshore-offshore gradient of seasonality within each system that were sampled at several stations. Spatial and seasonal patterns of POM composition are mainly due to local to regional processes such as hydrodynamics and sedimentary hydrodynamic (e.g. resuspension processes, changes in river flows, wind patterns influencing along-shore currents) but also due to the geomorphology of the systems (depth of the water column, distance to the shore). Future studies investigating the link between these forcings and POM composition would help to better understand the dynamics of POM composition in coastal systems. {\textcopyright} 2017 Elsevier Ltd}, keywords = {bacterium, benthos, biogeochemistry, Biological materials, C and n stable isotopes, C:N ratio, Carbon, carbon isotope, Coastal systems, coastal zone, Fluid dynamics, France, geomorphology, Hydrodynamics, Isotopes, isotopic ratio, Mediterranean sea, Meta analysis, meta-analysis, Mixing, Mixing models, nitrogen isotope, Organic compounds, particulate organic matter, Particulate organic matters, Phytoplankton, prokaryote, Rivers, seasonality, spatiotemporal analysis, stable isotope, Surface water, Surface waters, terrestrial deposit, Time series}, issn = {00796611}, doi = {10.1016/j.pocean.2017.03.001}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0079661116301914}, author = {Li{\'e}nart, Camilla and Savoye, Nicolas and Bozec, Yann and Elsa Breton and Conan, Pascal and David, Val{\'e}rie and Eric Feunteun and Karine Granger{\'e} and Kerherv{\'e}, P. and Lebreton, B. and S{\'e}bastien Lefebvre and St{\'e}phane L{\textquoteright}Helguen and Mousseau, Laure and Raimbault, P and Richard, P. and Riera, P. and Sauriau, P.-G. and Gauthier Schaal and Aubert, F. and Aubin, S. and Bichon, S. and Boinet, C. and Bourasseau, L. and Br{\'e}ret, M. and Caparros, J. and Cariou, T. and Charlier, K. and Claquin, P. and Vincent Cornille and Corre, A.-M. and Costes, L. and Crispi, O. and Muriel Crouvoisier and Czamanski, M. and Del Amo, Y. and Derriennic, H. and Dindinaud, F. and Durozier, M. and Hanquiez, V. and Antoine Nowaczyk and Devesa, J. and Ferreira, S. and Fornier, M. and Garcia, F. and Garcia, N. and Geslin, S. and Emilie Grossteffan and Gueux, A. and Guillaudeau, J. and Guillou, G. and Joly, O. and Lachauss{\'e}e, N. and Lafont, M. and Lamoureux, J. and Lecuyer, E. and Lehodey, J.-P. and Lemeille, D. and Leroux, C. and Mac{\'e}, E. and Maria, E. and Pineau, P. and Petit, F. and Pujo-Pay, M. and Rimelin-Maury, P. and Sultan, E.} }