@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 {Meddeb201967, title = {A new type of plankton food web functioning in coastal waters revealed by coupling Monte Carlo Markov chain linear inverse method and ecological network analysis}, journal = {Ecological Indicators}, volume = {104}, year = {2019}, note = {cited By 0}, pages = {67-85}, publisher = {Elsevier B.V.}, abstract = {Plankton food webs (PFW) typology is based on different categories of functioning, according to the dominant processes and the role played by heterotrophic bacteria, small vs large phytoplankton, and small vs large zooplankton. Investigating the structure and the function of planktonic food webs in two SW Mediterranean waters (inshore and marine sites) at four seasons, using inverse (LIM-MCMC) and ecological network (ENA) analyses, we identified a new type of food web, called the {\textquotedblleft}bacterial multivorous food web{\textquotedblright}. This food web adds to the conventional trophic continuum as previously reported. The {\textquotedblleft}bacterial multivorous food web{\textquotedblright} present in winter showed the lowest primary production among seasons, but highest bacterial production. Several food web ratios characterized this new typology e.g. picophytoplankton net primary production to total primary production varied from 0.20 to 0.28; bacterial to primary production ratio is higher than values reported in global scale (≅1); bacterial net production to the potential protozoan prey net production was high (\>0.2). In this special food web, carbon was mostly recycled, with a moderate fraction channeled to deep waters, which lead to a higher retention of carbon inside the ecosystem. This winter PFW also seemed to be the most organized, specialized, stable and mature, as related to common interpretations of ENA. The spring was characterized by herbivorous food web, with highest activity coinciding with low stability. Although less usual, the herbivorous pathway was also observed during summer, in inshore waters. The autumn food webs, which functioned as multivorous or microbial food webs, appeared to be stable and mature. Finally, our study demonstrates the usefulness of food web models derived ratios combined with ecological network analysis indices to conduct evaluation of the structure and functioning of ecosystems and potentially to support management decisions in marine environment. {\textcopyright} 2019}, keywords = {Bacteria (microorganisms), bacterium, Carbon, Chemical contamination, coastal water, Coastal waters, ecological modeling, Ecology, ecosystem function, Ecosystems, Electric network analysis, Food microbiology, food web, Food web model, Food webs, inverse analysis, Inverse problems, Markov chain, Markov processes, Mediterranean sea, Monte Carlo analysis, Monte Carlo methods, net primary production, network analysis, Phytoplankton, picoplankton, Plankton, Protozoa, protozoan, Seasonal variation, trophic status, Trophic structure}, issn = {1470160X}, doi = {10.1016/j.ecolind.2019.04.077}, url = {https://www.sciencedirect.com/science/article/abs/pii/S1470160X19303243}, author = {Meddeb, M. and Nathalie Niquil and Grami, B. and Mejri, K. and Haraldsson, M. and Chaalali, A. and Pringault, O. and Hlaili, A.S.} } @article {vanderHeijden201950, title = {Trophic importance of microphytobenthos and bacteria to meiofauna in soft-bottom intertidal habitats: A combined trophic marker approach}, journal = {Marine Environmental Research}, volume = {149}, year = {2019}, note = {cited By 2}, pages = {50-66}, publisher = {Elsevier Ltd}, abstract = {Meiofauna can play an important role in the carbon fluxes of soft-bottom coastal habitats. Investigation of their feeding behavior and trophic position remains challenging due to their small size. In this study, we determine and compare the food sources used by nematodes and benthic copepods by using stable isotope compositions, fatty acid profiles and compound specific isotope analyses of fatty acids in the mudflats, seagrass beds and a sandflat of the Marennes-Ol{\'e}ron Bay, France, and the Sylt-R{\o}m{\o} Bight, Germany. Suspended particulate organic matter was much more 13C-depleted than other food sources and meiofauna, highlighting its poor role in the different studied habitats. The very low proportions of vascular plant fatty acid markers in meiofauna demonstrated that these consumers did not rely on this food source, either fresh or detrital, even in seagrass beds. The combined use of stable isotopes and fatty acids emphasized microphytobenthos and benthic bacteria as the major food sources of nematodes and benthic copepods. Compound specific analyses of a bacteria marker confirmed that bacteria mostly used microphytobenthos as a substrate. {\textcopyright} 2019 Elsevier Ltd}, keywords = {Article, Bacillariophyta, bacteria, bacterium, Benthic copepods, Benthic diatoms, Biological materials, biomarker, Biomass, carbon 13, coastal zone, controlled study, Copepoda, delta carbon 13, delta nitrogen 15, Diatom, Ecosystems, fatty acids, Feeding Behavior, food supply, France, Free livings, Freeze Drying, Frisian Islands, Germany, high performance liquid chromatography, intertidal environment, isotope analysis, Isotopes, lipid composition, Marennes-Oleron Bay, Meiofauna, microbial activity, Microphytobenthos, mudflat, Mudflats, Nematoda, nitrogen 15, nonhuman, North Frisian Islands, Nouvelle-Aquitaine, Organic matter, Phytobenthos, Plants (botany), Sandflats, seagrass, Seagrass beds, Sediment, soft-bottom environment, species habitat, substrate, suspended particulate organic matter, Sylt-Romo Bight, trophic environment, Trophic markers, Trophic structure, unclassified drug}, issn = {01411136}, doi = {10.1016/j.marenvres.2019.05.014}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0141113618304744}, author = {van der Heijden, L.H. and Graeve, M. and R. Asmus and Rzeznik-Orignac, J. and Nathalie Niquil and Bernier, Q. and Guillou, G. and H Asmus and Lebreton, B.} } @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.} }