@article {9273, title = {Complex drivers of primary production along an anthropised estuary (Seine estuary{\textemdash}France)}, journal = {Frontiers in Environmental Science}, volume = {11}, year = {2023}, month = {May-06-2025}, doi = {10.3389/fenvs.2023.1216732}, url = {https://www.frontiersin.org/articles/10.3389/fenvs.2023.1216732/full}, author = {Serre-Fredj, L{\'e}on and Chasselin, L{\'e}o and Jolly, Orianne and Pascal Claquin} } @article {9192, title = {Data quality control considerations in multivariate environmental monitoring: experience of the French coastal network SOMLIT}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, month = {Feb-04-2025}, doi = {doi.org/10.3389/fmars.2023.1135446}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1135446/full}, author = {Breton, Elsa and Savoye, Nicolas and Rimmelin-Maury, Peggy and Sautour, Benoit and Goberville, Eric and Lheureux, Arnaud and Cariou, Thierry and Ferreira, Sophie and Agogue, Helene and Alliouane, Samir and Aubert, Fabien and Aubin, S{\'e}bastien and Berthebaud, Eric and Blayac, Hadrien and Blondel, Lucie and Boulart, C{\'e}dric and Bozec, Yann and Bureau, Sarah and Caillo, Arnaud and Cauvin, Arnaud and Cazes, Jean-Baptiste and Chasselin, L{\'e}o and Pascal Claquin and Conan, Pascal and Cordier, Marie-Ange and Costes, Laurence and Crec{\textquoteright}hriou, Romain and Crispi, Olivier and Crouvoisier, Muriel and David, Val{\'e}rie and Del Amo, Yolanda and De Lary, Hortense and Delebecq, Gaspard and Devesa, J{\'e}r{\'e}my and Domeau, Aur{\'e}lien and Durozier, Maria and Emery, Claire and Eric Feunteun and Juliette Fauchot and Gentilhomme, Val{\'e}rie and Geslin, Sandrine and Giraud, M{\'e}lanie and Granger{\'e}, Karine and Gr{\'e}gori, Gerald and Grossteffan, Emilie and Gueux, Aurore and Guillaudeau, Julien and Guillou, Ga{\"e}l and Harrewyn, Manon and Jolly, Orianne and Jude-Lemeilleur, Florence and Labatut, Paul and Labourdette, Nathalie and Lachauss{\'e}e, Nicolas and Lafont, Michel and Lagadec, V{\'e}ronique and Lambert, Christophe and Lamoureux, Jezebel and Lanceleur, Laurent and Lebreton, Beno{\^\i}t and Lecuyer, Eric and Lemeille, David and Leredde, Yann and Leroux, C{\'e}dric and Leynaert, Aude and L{\textquoteright}Helguen, St{\'e}phane and Li{\'e}nart, Camilla and Mac{\'e}, Eric and Maria, Eric and Marie, Barbara and Marie, Dominique and Mas, S{\'e}bastien and Mendes, Fabrice and Mornet, Line and Mostajir, Behzad and Mousseau, Laure and Nowaczyk, Antoine and Nunige, Sandra and Parra, Ren{\'e} and Paulin, Thomas and Pecqueur, David and Petit, Franck and Pineau, Philippe and Raimbault, Patrick and Rigaut-Jalabert, Fabienne and Salmeron, Christophe and Salter, Ian and Sauriau, Pierre-Guy and Seuront, Laurent and Sultan, Emmanuelle and Vald{\`e}s, R{\'e}mi and Vantrepotte, Vincent and Vidussi, Francesca and Voron, Florian and Vuillemin, Renaud and Zudaire, Laurent. and Garcia, Nicole} } @article {9393, title = {Influence of nutrient enrichment on colonisation and photosynthetic parameters of hard substrate marine microphytobenthos}, journal = {Biofouling}, year = {2023}, month = {Feb-10-2023}, pages = {1 - 18}, abstract = {This study aimed to assess the influence of nutrient enrichment on the development of microalgal biofilm on concrete and PVC cubes. Three mesocosms were utilized to create a nutrient gradient over a period of 28 days. Various parameters including biomass, photosynthetic activity, microtopography, and extracellular polymeric substances (EPS) were measured. Imaging PAM techniques were employed to obtain surface-wide data. Results revealed that nutrient availability had no significant impact on Chl a biomass and the maximum quantum efficiency of PSII (Fv/Fm). The photosynthetic capacity and efficiency were minimally affected by nutrient availability. Interestingly, the relationship between microphytobenthic (MPB) biomass and photosynthesis and surface rugosity exhibited distinct patterns. Negative reliefs showed a strong correlation with Fv/Fm, while no clear pattern emerged for biomass on rough concrete structures. Overall, our findings demonstrate that under conditions of heightened eutrophication, biofilm photosynthesis thrives in the fissures and crevasses of colonized structures regardless of nutrient levels. This investigation provides valuable insights into the interplay between nutrient availability and surface rugosity.}, issn = {0892-7014}, doi = {10.1080/08927014.2023.2261852}, url = {https://www.tandfonline.com/doi/full/10.1080/08927014.2023.2261852}, author = {Vivier, Baptiste and Faucheux-Bourlot, Caroline and Orvain, Francis and Chasselin, L{\'e}o and Jolly, Orianne and Navon, Maxime and Boutouil, Mohamed and Goux, Didier and Dauvin, Jean-Claude and Pascal Claquin} } @article {9052, title = {Physiological conditions favorable to domoic acid production by three Pseudo-nitzschia species}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {559}, year = {2023}, month = {Jan-02-2023}, pages = {151851}, issn = {00220981}, doi = {10.1016/j.jembe.2022.151851}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0022098122001599}, author = {Aurore Sauvey and Pascal Claquin and Le Roy, Bertrand and Jolly, Orianne and Juliette Fauchot} } @article {8478, title = {Colimitation assessment of phytoplankton growth using a resource use efficiency approach in the Bay of Seine (French-English Channel)}, journal = {Journal of Environmental Management}, volume = {306}, year = {2022}, month = {Jan-03-2022}, pages = {114487}, issn = {03014797}, doi = {10.1016/j.jenvman.2022.114487}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0301479722000603}, author = {Serre-Fredj, L{\'e}on and Chasselin, L{\'e}o and Jolly, Orianne and Jacqueline, Franck and Pascal Claquin} } @article {8735, title = {Colonisation of artificial structures by primary producers: competition and photosynthetic behaviour}, journal = {Biofouling}, year = {2022}, month = {Apr-06-2023}, pages = {1 - 14}, issn = {0892-7014}, doi = {10.1080/08927014.2022.2088285}, url = {https://www.tandfonline.com/doi/full/10.1080/08927014.2022.2088285}, author = {Vivier, Baptiste and Navon, Maxime and Dauvin, Jean-Claude and Chasselin, L{\'e}o and Deloor, Ma{\"e}l and Orvain, Francis and Rusig, Anne-Marie and Mussio, Isabelle and Boutouil, Mohamed and Pascal Claquin} } @article {8467, title = {Interaction between the diatom Cylindrotheca closterium and a siliceous mortar in a silica-limited environment}, journal = {Construction and Building Materials}, volume = {321}, year = {2022}, month = {Jan-02-2022}, pages = {126277}, issn = {09500618}, doi = {10.1016/j.conbuildmat.2021.126277}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0950061821040071}, author = {Georges, Marine and Bourguiba, Amel and Boutouil, Mohamed and Chateigner, Daniel and Jolly, Orianne and Pascal Claquin} } @article {8635, title = {Organic Phosphorus Scavenging Supports Efficient Growth of Diazotrophic Cyanobacteria Under Phosphate DepletionData_Sheet_1.docx}, journal = {Frontiers in Microbiology}, volume = {13}, year = {2022}, month = {Jan-03-2024}, doi = {10.3389/fmicb.2022.84864710.3389/fmicb.2022.848647.s001}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2022.848647/full}, author = {Rabouille, Sophie and Tournier, Lauralie and Duhamel, Solange and Pascal Claquin and Crispi, Olivier and Talec, Am{\'e}lie and Landolfi, Angela and Oschlies, Andreas} } @article {8540, title = {A review of methods and indicators used to evaluate the ecological modifications generated by artificial structures on marine ecosystems}, journal = {Journal of Environmental Management}, volume = {310}, year = {2022}, month = {Jan-05-2022}, pages = {114646}, issn = {03014797}, doi = {10.1016/j.jenvman.2022.114646}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0301479722002195}, author = {Taormina, Bastien and Pascal Claquin and Vivier, Baptiste and Navon, Maxine and Pezy, Jean-Philippe and Raoux, Aurore and Dauvin, Jean-Claude} } @article {7947, title = {Coupling high frequency monitoring and bioassay experiments to investigate a harmful algal bloom in the Bay of Seine (French-English Channel)}, journal = {Marine Pollution Bulletin}, volume = {168}, year = {2021}, month = {Jan-07-2021}, pages = {112387}, abstract = {Coastal ecosystems are increasingly threatened by eutrophication and dystrophy. In this context, the full pattern of a bloom dominated by the dinoflagellate, Lepidodinium chlorophorum, was investigated by a high frequency monitoring buoy equipped with sensors allowing nutrients and photosynthesis measurements. An increase of the N/P ratio affected phytoplankton physiology leading to bloom collapse with a slight oxygen depletion. In parallel, enrichment experiments were performed on the natural bloom population. After 5 days of incubation the community structure, using flow cytometry and several physiological parameters were analysed. The data reveal a potential N and P co-limitation and a decoupling between primary production and productivity in fully enriched conditions. Under unbalanced N/P inputs, high level of alkaline phosphatase activity and transparent exopolymeric particle production, which favour phytoplankton sedimentation, were observed. Nutrient inputs and their stoichiometry control phytoplankton growth, the community structure, physiological regulations, the fate of the bloom and consequences.}, issn = {0025326X}, doi = {10.1016/j.marpolbul.2021.112387}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0025326X21004215}, author = {Serre-Fredj, L{\'e}on and Jacqueline, Franck and Navon, Maxime and Izabel, Guillaume and Chasselin, L{\'e}o and Jolly, Orianne and R{\'e}p{\'e}caud, Michel and Pascal Claquin} } @article {8020, title = {Decadal trajectories of phytoplankton communities in contrasted estuarine systems in an epicontinental sea}, journal = {Estuarine, Coastal and Shelf Science}, volume = {258}, year = {2021}, month = {Jan-09-2021}, pages = {107409}, abstract = {In coastal areas, global changes are known to affect estuaries and their plume leading to water temperature increase and river discharge variations, which are two of the main drivers controlling phytoplankton dynamics. This paper aims at understanding the past 10 years{\textquoteright} variations in term of communities{\textquoteright} stability and trajectories along with their relationship with the environment. Considering the high environmental variability along coastal areas, we focused our study on six contrasted estuarine systems from the eastern English Channel. Using monthly monitoring from 2008 to 2019, the response of the micro-phytoplankton compartment was investigated through the abundances of a hundred taxa and several abiotic parameters{\textquoteright} records. The results indicate an overall stability in community composition with an average of 30{\textendash}40\% similarity between pairs of samples over the study period. The phytoplankton assemblages also display greater spatial heterogeneity during summer in comparison with other seasons. The co-inertia analysis highlighted four separate systems linked to major drivers; a system under strong river and nutrient flows influence, a well-mixed and oxygenized estuary, a system challenged by offshore marine waters, and finally a system under shellfish farms pressure. This structuration is built from the dominance of a handful of species that differs from one place to another, which explains why phytoplankton is mostly site specific. Additionally, the low variations led a by few species{\textquoteright} dominance also explains the interannual stability noticed during summer at each area, in spite of the high diversity observed.}, issn = {02727714}, doi = {10.1016/j.ecss.2021.107409}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0272771421002626}, author = {Lefran, Ang{\'e}line and Hern{\'a}ndez-Fari{\~n}as, Tania and Gohin, Francis and Pascal Claquin} } @article {7915, title = {Electron \& Biomass Dynamics of Cyanothece Under Interacting Nitrogen \& Carbon Limitations}, journal = {Frontiers in Microbiology}, volume = {12}, year = {2021}, month = {04/2021}, doi = {10.3389/fmicb.2021.61780210.3389/fmicb.2021.617802.s001}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2021.617802/full}, author = {Rabouille, Sophie and Campbell, Douglas A. and Masuda, Takako and Zav{\v r}el, Tomas and Bern{\'a}t, Gabor and Polerecky, Lubos and Halsey, Kimberly and Eichner, Meri and Kotabov{\'a}, Eva and Stephan, Susanne and Luke{\v s}, Martin and Pascal Claquin and Bonomi-Barufi, Jose and Lombardi, Ana Teresa and {\v C}erven{\'y}, Jan and Suggett, David J. and Giordano, Mario and Kromkamp, Jacco C. and Pr{\'a}{\v s}il, Ondrej} } @article {8349, title = {Four-Year Temporal Study of an Intertidal Artificial Structure in the English Channel}, journal = {Journal of Marine Science and Engineering}, volume = {9}, year = {2021}, month = {Jan-11-2021}, pages = {1174}, doi = {10.3390/jmse9111174}, url = {https://www.mdpi.com/2077-1312/9/11/1174}, author = {Dauvin, Jean-Claude and Deloor, Ma{\"e}l and Pezy, Jean-Philippe and Raoux, Aurore and Pascal Claquin and Foveau, Aur{\'e}lie} } @article {8109, title = {Influence of infrastructure material composition and microtopography on marine biofilm growth and photobiology}, journal = {Biofouling}, year = {2021}, month = {Apr-08-2022}, pages = {1 - 17}, issn = {0892-7014}, doi = {10.1080/08927014.2021.1959918}, url = {https://www.tandfonline.com/doi/full/10.1080/08927014.2021.1959918}, author = {Vivier, Baptiste and Pascal Claquin and Lelong, Christophe and Lesage, Quentin and Peccate, Mathias and Hamel, Bastien and Georges, Marine and Bourguiba, Amel and Sebaibi, Nassim and Boutouil, Mohamed and Goux, Didier and Dauvin, Jean-Claude and Francis Orvain} } @article {7854, title = {Marine artificial reefs, a meta-analysis of their design, objectives and effectiveness}, journal = {Global Ecology and Conservation}, year = {2021}, month = {Jan-03-2021}, pages = {e01538}, issn = {23519894}, doi = {10.1016/j.gecco.2021.e01538}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2351989421000883}, author = {Vivier, Baptiste and Dauvin, Jean-Claude and Navon, Maxime and Anne-Marie Rusig and Isabelle Mussio and Francis Orvain and Boutouil, Mohamed and Pascal Claquin} } @article {8420, title = {Quantifying Cyanothece growth under DIC limitation}, journal = {Computational and Structural Biotechnology Journal}, year = {2021}, month = {Jan-11-2021}, issn = {20010370}, doi = {10.1016/j.csbj.2021.11.036}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2001037021005018}, author = {Inomura, Keisuke and Masuda, Takako and Eichner, Meri and Rabouille, Sophie and Zav{\v r}el, Tomas and {\v C}erven{\'y}, Jan and Vancov{\'a}, Marie and Bern{\'a}t, Gabor and Armin, Gabrielle and Pascal Claquin and Kotabov{\'a}, Eva and Stephan, Susanne and Suggett, David J. and Deutsch, Curtis and Pr{\'a}{\v s}il, Ondrej} } @article {7636, title = {Singular physiological behavior of the scleractinian coral Porites astreoides in the dark phase}, journal = {Coral Reefs}, volume = {doi.org/10.1007/s00338-020-02023-4}, year = {2021}, month = {12/2020}, pages = {139-150}, abstract = {Unlike most other corals that have been declining since the 1980s, the population of Porites astreoides, one of the dominant species of coral in Caribbean reefs, appears to be resilient. We investigated the physiological regulation of the electron transport chain of Symbiodiniaceae chloroplasts during the light / dark transition in P. astreoides compared to nine other common scleractinian corals. Protocols were applied to coral samples in seawater tanks and in situ. The maximum quantum yield (Fv/Fm) in the dark and the effective photochemical efficiency (Fq{\textquoteright}/Fm{\textquoteright}) in the light were measured during light-dark transitions, and alternative electron flow (AEF) mechanisms were evaluated using fluorescence variation in response to serial irradiation pulses (SIP-protocol). The variation in Fv/Fm (ΔYIImax) was calculated after 3 min or 2 h of dark acclimation (ΔYIImax(2h); ΔYIImax(3min)). The three species that belong to the genus Porites (P. astreoides, P. divaricata, P. furcata) showed plastoquinone reduction (PQ) in response to the SIP protocol, unlike all the other species tested. A marked decrease in Fv/Fm (ΔYIImax(2h) = 47.79\%) was observed in P. astreoides in the dark whereas the average ΔYIImax(2h) of the other species tested was 0.677\%. The decrease in ΔYIImax in P. astreoides was due to a significant increase in Fo (ΔFo(2h) = -108.64\% {\textpm} SD 21.48) whereas Fm remained relatively stable. The increase in Fo was attributed to reduction of the PQ pool through a chlororespiration-like mechanism known to reduce the production of reactive oxygen species (ROS). This mechanism was triggered immediately after exposure to the dark, while a brief and moderate light exposure reversed it. Given the ecological success of P. astreoides, we suggest that the high antioxidant capability of this species in the dark phase could be one of the factors favoring its survival in the face of various environmental and anthropogenic threats.
\ }, keywords = {Caribbean reef corals, chlororespiration-like, PAM, resilience}, url = {https://link.springer.com/article/10.1007/s00338-020-02023-4}, author = {Pascal Claquin and Ren{\'e}-Trouillefou, Malika and Pascal Jean Lopez and Japaud, Aur{\'e}lien and Yolande Bouchon-Navaro and S{\'e}bastien Cordonnier and Claude Bouchon} } @article {7853, title = {Temporal Patterns and Intra- and Inter-Cellular Variability in Carbon and Nitrogen Assimilation by the Unicellular Cyanobacterium Cyanothece sp. ATCC 51142Data_Sheet_1.pdfData_Sheet_2.XLSX}, journal = {Frontiers in Microbiology}, volume = {12}, year = {2021}, month = {Apr-02-2021}, doi = {10.3389/fmicb.2021.62091510.3389/fmicb.2021.620915.s00110.3389/fmicb.2021.620915.s002}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2021.620915/full}, author = {Polerecky, Lubos and Masuda, Takako and Eichner, Meri and Rabouille, Sophie and Vancov{\'a}, Marie and Kienhuis, Michiel V. M. and Bern{\'a}t, Gabor and Bonomi-Barufi, Jose and Campbell, Douglas Andrew and Pascal Claquin and {\v C}erven{\'y}, Jan and Giordano, Mario and Kotabov{\'a}, Eva and Kromkamp, Jacco and Lombardi, Ana Teresa and Luke{\v s}, Martin and Pr{\'a}{\v s}il, Ondrej and Stephan, Susanne and Suggett, David and Zav{\v r}el, Tomas and Halsey, Kimberly H.} } @article {7195, title = {Evidence for better microphytobenthos dynamics in mixed sand/mud zones than in pure sand or mud intertidal flats (Seine estuary, Normandy, France)}, journal = {PLOS ONE}, volume = {15}, year = {2020}, month = {08/2020}, pages = { e0237211}, abstract = {Understanding the dynamics of microphytobenthos biomass and photosynthetic performances in intertidal ecosystems will help advance our understanding of how trophic networks function in order to optimize ecological management and restoration projects. The main objective of this study was to investigate microphytobenthic biomass and photosynthetic performances as a function of the sedimentary and environmental variabilities in the range of intertidal habitats in the downstream Seine estuary (Normandy, France). Our results highlight higher biomass associated with more stratified biofilms and better photosynthetic performances in areas characterized by a sand/mud mixture (40{\textendash}60\% of mud) compared to pure sand or pure mud environments. This type of sediment probably offers an efficient trade-off between the favorable characteristics of the two types of sediments (sand and mud) with respect to light penetration and nutrient accessibility. Moreover, the large quantities of exopolysaccharides produced in sand/mud mixtures emphasizes the functional role played by microphytobenthos in promoting sediment stability against erosion. This allows us to show that despite the strong increase in sand content of the downstream Seine estuary, intertidal flats are still productive since microphytobenthic biomass, photosynthetic performances and exopolysaccharides secretion are highest in sand-mud mixtures. This study also underlines the impact of ecosystem modifications due to human disturbance and climate change on the dynamics of key primary producers in estuaries.}, doi = {10.1371/journal.pone.0237211}, author = {Morelle, J{\'e}r{\^o}me and Pascal Claquin and Francis Orvain} } @article {6656, title = {Differential Influence of Life Cycle on Growth and Toxin Production of three Pseudo-nitzschia Species (Bacillariophyceae)}, journal = {Journal of Phycology}, volume = {55}, year = {2019}, pages = {1126-1139}, abstract = {We used a multistrain approach to study the intra- and interspecific variability of the growth rates of three Pseudo-nitzschia species {\textendash} P. australis, P. fraudulenta, and P. pungens {\textendash} and of their domoic acid (DA) production. We carried out mating and batch experiments to investigate the respective effects of strain age and cell size, and thus the influence of their life cycle on the physiology of these species. The cell size {\textendash} life cycle relationship was characteristic of each species. The influence of age and cell size on the intraspecific variability of growth rates suggests that these characteristics should be considered cautiously for the strains used in physiological studies on Pseudo-nitzschia species. The results from all three species do not support the hypothesis of a decrease in DA production with time since isolation from natural populations. In P. australis, the cellular DA content was rather a function of cell size. More particularly, cells at the gametangia stage of their life cycle contained up to six times more DA than smaller or larger cells incapable of sexual reproduction. These findings reveal a link between P. australis life cycle and cell toxicity. This suggest that life cycle dynamics in Pseudo-nitzschia natural populations may influence bloom toxicity. {\textcopyright} 2019 Phycological Society of America}, issn = {00223646}, doi = {10.1111/jpy.12898}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.12898}, author = {Aurore Sauvey and Pascal Claquin and Le Roy, Bertrand and Le Gac, Mickael and Juliette Fauchot} } @article {8745, title = {Differential Influence of Life Cycle on Growth and Toxin Production of three Pseudo-nitzschia species (Bacillariophyceae)}, journal = {Journal of Phycology}, volume = {55}, year = {2019}, month = {Mar-10-2021}, pages = {1126 - 1139}, issn = {0022-3646}, doi = {10.1111/jpy.v55.510.1111/jpy.12898}, url = {https://onlinelibrary.wiley.com/toc/15298817/55/5}, author = {Aurore Sauvey and Pascal Claquin and Bertrand Le Roy and Le Gac, Mickael and Juliette Fauchot}, editor = {Kroth, P.} } @article {5428, title = {Annual Phytoplankton Primary Production Estimation in a Temperate Estuary by Coupling PAM and Carbon Incorporation Methods}, journal = {Estuaries and Coasts}, year = {2018}, month = {02/2018}, abstract = {

Phytoplankton primary production varies considerably with environmental parameters especially in dynamic ecosystems like estuaries. The aimof this study was to investigate short-term primary production along the salinity gradient of a temperate estuary over the course of 1 year. The combination of carbon incorporation and fluorescence methods enabled primary production estimation at short spatial and temporal scales. The electron requirement for carbon fixation was investigated in relation with physical-chemical parameters to accurately estimate primary production at high frequency. These results combined with the variability of the photic layer allowed the annual estimation of primary production along the estuary. Phytoplankton dynamics was closely related to salinity and turbidity gradients, which strongly influenced cells physiology and photoacclimatation. The number of electrons required to fix 1 mol of carbon (C) was ranged between 1.6 and 25 mol electron mol C-1 with a mean annual value of 8 {\textpm} 5 mol electron mol C-1. This optimum value suggests that in nutrient replete conditions like estuaries, alternative electron flows are low, while electrons transfer from photosystem II to carbon fixation is highly efficient. A statistical model was used to improve the estimation of primary production from electron transport rate as a function of significant environmental parameters. Based on this model, daily carbon production in the Seine estuary (France) was estimated by considering light and photic zone variability. A mean annual daily primary production of 0.12 {\textpm} 0.18 g C m-2 day-1 with a maximum of 1.18 g C m-2 day-1 in summer was estimated which lead to an annual mean of 64.75 g C m-2 year-1. This approach should be applied more frequently in dynamic ecosystems such as estuaries or coastal waters to accurately estimate primary production in those valuable ecosystems.

}, keywords = {High frequency . Electron requirement for carbon fixation . Electron transport rate (ETR) . Seine estuary}, author = {Morelle, J{\'e}r{\^o}me and Mathilde Schapira and Francis Orvain and Riou, Philippe and Pascal Jean Lopez and Duplessix, Olivier and Rabiller, Emilie and Maheux, Franc and Simon, Benjamin and Pascal Claquin} } @article {5586, title = {Dynamics of exopolymeric carbon pools in relation with phytoplankton succession along the salinity gradient of a temperate estuary (France)}, journal = {Estuarine, Coastal and Shelf Science}, volume = {209}, year = {2018}, pages = {18-29}, abstract = {

In parallel to phytoplankton community dynamics, transparent exopolymeric particles (TEP) and exopolymeric
substances (EPS) were investigated along the salinity gradient of a temperate estuary (Seine estuary, Normandy,
France) over the course of a year. The phytoplankton community was mainly dominated by marine diatom
species (especially Skeletonema sp., Nitzschia sp., and Paralia sulcata) associated with a spring bloom of picoeukaryotes
and the development of Cryptophyceae in summer. The decreases in species richness and salinity were
correlated along the estuary and a significant exponential relationship between species richness and primary
production was identified. Concentrations of TEP and EPS (soluble and bound carbohydrates) are highly dynamic
in this estuary and can reach respectively 69 mgC L-1, and 33 mgC L-1. TEP distribution was mainly
related to physical factors (hydrodynamics, maximum turbidity zone formation and sediment resuspension)
probably produced by stressed or dying phytoplankton, while EPS appeared to be excreted during the phytoplankton
spring bloom. Soluble and bound EPS appear to be related to Skeletonema sp. and Cryptophyceae occurrences.
This paper presents the dynamic pattern of these carbon pools, which play an important role in the
trophic network and influence the flocculation processes involved in the fate of both organic and inorganic
matter.

}, keywords = {Exopolymeric substances Species, Nanophytoplankton, Picophytoplankton, richness}, author = {Morelle, J{\'e}r{\^o}me and Mathilde Schapira and Fran{\c c}oise, Sylvaine and Courtay Ga{\"e}lle and Francis Orvain and Pascal Claquin} } @article {5434, title = {Electron requirements for carbon incorporation along a diel light cycle in three marine diatom species}, journal = {Photosynthesis Research}, year = {2018}, pages = {1-14}, abstract = {

Diatoms account for about 40\% of primary production in highly productive ecosystems. The development of a new generation of fluorometers has made it possible to improve estimation of the electron transport rate from photosystem II, which, when coupled with the carbon incorporation rate enables estimation of the electrons required for carbon fixation. The aim of this study was to investigate the daily dynamics of these electron requirements as a function of the diel light cycle in three relevant diatom species and to apprehend if the method of estimating the electron transport rate can lead to different pictures of the dynamics. The results confirmed the species-dependent capacity for photoacclimation under increasing light levels. Despite daily variations in the photosynthetic parameters, the results of this study underline the low daily variability of the electron requirements estimated using functional absorption of the photosystem II compared to an estimation based on a specific absorption cross section of chlorophyll a. The stability of the electron requirements throughout the day would suggest it is potentially possible to estimate high-frequency primary production by using autonomous variable fluorescence measurements from ships-of-opportunity or moorings, without taking potential daily variation in this parameter into consideration, but this result has to be confirmed on natural phytoplankton assemblages. The results obtained in this study confirm the low electron requirements of diatoms to perform photosynthesis, and suggest a potential additional source of energy for carbon fixation, as recently described in the literature for this class.

}, doi = {https://doi.org/10.1007/s11120-018-0491-2}, url = {https://link.springer.com/article/10.1007\%2Fs11120-018-0491-2}, author = {Morelle, J{\'e}r{\^o}me and Pascal Claquin} } @article {5435, title = {A simple, user friendly tool to readjust raw PAM data from field measurements to avoid over- or underestimating of microphytobenthos photosynthetic parameters}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {503}, year = {2018}, pages = {136-146}, abstract = {

Intertidal mudflats are among the most productive ecosystems and microphytobenthic (MPB) biofilms play a key role in primary production. MPB primary production varies at short spatial and temporal scales. Accurate measurements thus require rapid non-intrusive methods like pulse amplitude modulate (PAM) fluorescence. However, the effect of granulometry and chl a concentration profile in light attenuation on irradiance and on fluorescence signal in the photic layer need to be taken into account when primary production is estimated using PAM. We propose a tool to readjust raw photosynthetic parameters (rETRmax, α, Ik) estimated from PAM measurements on the field, to avoid over- or underestimation. To develop the tool, we used models previously designed by K{\"u}hl and J{\o}rgensen (1992), Ser{\^o}dio (2004) and Forster and Kromkamp (2004) by integrating the chl a distribution profiles and sediment granulometry from pure sand to pure mud. The sensitivity of the correction to sediment granulometry and the shape of chl a profile were evaluated theoretically using a typical fluorescence data set obtained using PAM measurements. Our results confirm the importance of accounting for both the chl a profile and sediment granulometry when estimating a light attenuation coefficient. We show that, with the same chl a profile, the photosynthetic parameters are more underestimated in mud than in a sandy environment. Thus, granulometry and the chl a profile need to be systematically quantified and used to correct raw data measured in field studies using PAM before estimating photosynthetic parameters. The numerical tool is available as an e-document that is simple and easy to apply to any PAM data.

}, doi = {https://doi.org/10.1016/j.jembe.2018.02.007}, url = {https://www.sciencedirect.com/science/article/pii/S0022098117303325}, author = {Morelle, J{\'e}r{\^o}me and Francis Orvain and Pascal Claquin} } @article {5136, title = {Dynamics of phytoplankton productivity and exopolysaccharides (EPS and TEP) pools in the Seine Estuary (France, Normandy) over tidal cycles and over two contrasting seasons}, journal = {Marine Environmental Research}, year = {2017}, month = {09/2017}, author = {Morelle, J{\'e}r{\^o}me and Mathilde Schapira and Pascal Claquin} } @article {Thorel2017192, title = {Nutrient ratios influence variability in Pseudo-nitzschia species diversity and particulate domoic acid production in the Bay of Seine (France)}, journal = {Harmful Algae}, volume = {68}, year = {2017}, note = {cited By 15}, pages = {192-205}, publisher = {Elsevier B.V.}, abstract = {The population dynamics of different Pseudo-nitzschia species, along with particulate domoic acid (pDA) concentrations, were studied from May 2012 to December 2013 in the Bay of Seine (English Channel, Normandy). While Pseudo-nitzschia spp. blooms occurred during the two years of study, Pseudo-nitzschia species diversity and particulate domoic acid concentrations varied greatly. In 2012, three different species were identified during the spring bloom (P. australis, P. pungens and P. fraudulenta) with high pDA concentrations (\~{}1400 ng l-1) resulting in shellfish harvesting closures. In contrast, the 2013 spring was characterised by a P. delicatissima bloom without any toxic event. Above all, the results show that high pDA concentrations coincided with the presence of P. australis and with potential silicate limitation (Si:N \< 1), while nitrate concentrations were still replete. The contrasting environmental conditions between 2012 and 2013 highlight different environmental controls that might favour the development of either P. delicatissima or P. australis. This study points to the key role of Pseudo-nitzschia diversity and cellular toxicity in the control of particulate domoic acid variations and highlights the fact that diversity and toxicity are influenced by nutrients, especially nutrient ratios. {\textcopyright} 2017 Elsevier B.V.}, keywords = {analogs and derivatives, analysis, Bay, Bays, Biodiversity, chemistry, Diatom, Diatoms, Domoic acid, France, Geography, kainic acid, Nitrates, nitric acid derivative, particulate matter, phosphate, Phosphates, Physiology, Phytoplankton, Principal Component Analysis, season, Seasons, species difference, Species Specificity, time factor, Time Factors}, issn = {15689883}, doi = {10.1016/j.hal.2017.07.005}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028543709\&doi=10.1016\%2fj.hal.2017.07.005\&partnerID=40\&md5=def23b37b0d16a1ae7ab65a7ef2b940b}, author = {Thorel, Maxine and Pascal Claquin and Mathilde Schapira and Romain Le Gendre and Riou, Philippe and Didier Goux and Bertrand Le Roy and Raimbault, V and Deton-Cabanillas, A.-F. and Bazin, Pauline and Kientz-Bouchart, Val{\'e}rie and Juliette Fauchot} } @article {5143, title = {Nutrient ratios influence variability in Pseudo-nitzschia species diversity and particulate domoic acid production in the Bay of Seine (France)}, journal = {Harmful Algae}, volume = {68}, year = {2017}, pages = {192 - 205}, abstract = {

The population dynamics of different Pseudo-nitzschia species, along with particulate domoic acid (pDA) concentrations, were studied from May 2012 to December 2013 in the Bay of Seine (English Channel, Normandy). While Pseudo-nitzschia spp. blooms occurred during the two years of study, Pseudo-nitzschia species diversity and particulate domoic acid concentrations varied greatly. In 2012, three different species were identified during the spring bloom (P. australis, P. pungens and P. fraudulenta) with high pDA concentrations (\~{}1400\ ng\ l-1) resulting in shellfish harvesting closures. In contrast, the 2013 spring was characterised by a P. delicatissima bloom without any toxic event. Above all, the results show that high pDA concentrations coincided with the presence of P. australis and with potential silicate limitation (Si:N\ \<\ 1), while nitrate concentrations were still replete. The contrasting environmental conditions between 2012 and 2013 highlight different environmental controls that might favour the development of either P. delicatissima or P. australis. This study points to the key role of Pseudo-nitzschia diversity and cellular toxicity in the control of particulate domoic acid variations and highlights the fact that diversity and toxicity are influenced by nutrients, especially nutrient ratios.

}, keywords = {Bloom dynamics, Domoic acid, English Channel, Nutrient ratios, Pseudo-nitzschia Species diversity}, issn = {1568-9883}, doi = {https://doi.org/10.1016/j.hal.2017.07.005}, url = {http://www.sciencedirect.com/science/article/pii/S1568988317300148}, author = {Thorel, Maxine and Pascal Claquin and Mathilde Schapira and Romain Le Gendre and Riou, Philippe and Goux, Didier and Le Roy, Bertrand and Raimbault, V and Deton-Cabanillas, Anne-Flore and Bazin, Pauline and Kientz-Bouchart, Val{\'e}rie and Juliette Fauchot} } @article {4341, title = {Physiological adjustments and transcriptome reprogramming are involved in the acclimation to salinity gradients in diatoms}, journal = {Environmental Microbiology}, volume = {19}, year = {2017}, month = {5}, pages = {909-925}, abstract = {

Salinity regimes in estuaries and coastal areas vary with river discharge patterns, seawater evaporation, the morphology of the coastal waterways, and the dynamics of marine water mixing. Therefore, microalgae have to respond to salinity variations at time scales ranging from daily to annual cycles. Microalgae may also have to adapt to physical alterations that induce the loss of connectivity between habitats and the enclosure of bodies of water. Here, we integrated physiological assays and measurements of morphological plasticity with a functional genomics approach to examine the regulatory changes that occur during the acclimation to salinity in the estuarine diatom Thalassiosira weissflogii. We found that cells exposed to different salinity regimes for a short or long period presented adjustments in their carbon fractions, silicon pools, pigment concentrations and/or photosynthetic parameters. Salinity-induced alterations in frustule symmetry were observed only in the long-term cultures. Whole transcriptome analyses revealed a down-regulation of nuclear and plastid encoded genes during the long-term response and identified only a few regulated genes that were in common between the short- and long-term responses. We propose that in diatoms, one strategy for acclimating to salinity gradients and maintaining optimal cellular fitness could be a reduction in the cost of transcription. This article is protected by copyright. All rights reserved.

}, issn = {1462-2920}, doi = {10.1111/1462-2920.13398}, url = {http://dx.doi.org/10.1111/1462-2920.13398}, author = {Adrien Bussard and Corre, Erwan and C{\'e}dric Hubas and Duvernois-Berthet, Evelyne and Gildas Le Corguille and Jourdren, Laurent and Coulpier, Fanny and Pascal Claquin and Pascal Jean Lopez} } @article {4041, title = {The Channel ecosystem, a cross-roads of anthropogenic pressures and scientific studies: Lessons learned from the European \{INTERREG\} \{IV\} projects (2009{\textendash}2015)}, journal = {Marine Policy}, volume = {63}, year = {2016}, month = {11/2015}, pages = {158 - 165}, author = {L Evariste and Pascal Claquin and Jean-Paul Robin and Arnaud Auber and Abigail McQuatters-Gollop and Jean-Claude Dauvin} } @article {4515, title = {Dynamics of δ(15)N isotopic signatures of different intertidal macroalgal species: Assessment of bioindicators of N sources in coastal areas.}, journal = {Mar Pollut Bull}, volume = {110}, year = {2016}, month = {2016 Sep 15}, pages = {470-83}, abstract = {

δ(15)N of annual (Ulva sp., Porphyra sp.) and perennial intertidal seaweed species (Chondrus crispus, Fucus sp.) collected on 17 sampling points along the French coast of the English Channel in 2012 and 2013 were assessed on their suitability as bioindicators of N pollution in coastal areas. A sine function applied for δ(15)N time series data showed for all the species the same seasonal trend with lowest δ(15)N values in April and highest in summer but with no significant interspecific differences of amplitude (α) and phase angle (ϕ). This model provides a useful tool for monitoring the inter-annual changes of N pollution. An interspecific variability of δ(15)N values was observed, probably due to their tolerance to emersion. An in vitro study for comparing the kinetic acquisition of the isotopic signal and N uptake mechanisms of each species underlined the influence of algal physiology on the δ(15)N interspecific variability.

}, issn = {1879-3363}, doi = {10.1016/j.marpolbul.2016.06.006}, author = {St{\'e}phanie Lemesle and Erraud, Alexandre and Isabelle Mussio and Anne-Marie Rusig and Pascal Claquin} } @article {4516, title = {Photosystem-II shutdown evolved with Nitrogen fixation in the unicellular diazotroph Crocosphaera watsonii.}, journal = {Environ Microbiol}, volume = {18}, year = {2016}, month = {2016 Feb}, pages = {477-85}, abstract = {

Protection of nitrogenase from oxygen in unicellular Cyanobacteria is obtained by temporal separation of photosynthesis and diazotrophy through transcriptional and translational regulations of nitrogenase. But diazotrophs can face environmental situations in which N2 fixation occurs significantly in the light, and we believe that another control operates to make it possible. The night-time shutdown of PSII activity is a peculiar behaviour that discriminates Crocosphaera watsonii WH8501 from any other phototroph, whether prokaryote or eukaryote. This phenomenon is not only due to the plastoquinone pool redox status, and suggests that the sentinel D1 protein, expressed in periods of nitrogen fixation, is inactive. Results demonstrate a tight constraint of oxygen evolution in C. watsonii as additional protection of nitrogenase activity and suggest a possible recycling of cellular components.

}, issn = {1462-2920}, doi = {10.1111/1462-2920.13157}, author = {Rabouille, Sophie and Pascal Claquin} } @article {3865, title = {Impact of seaweed beachings on dynamics of δ(15)N isotopic signatures in marine macroalgae.}, journal = {Mar Pollut Bull}, year = {2015}, month = {2015 Jun 18}, abstract = {

A fine-scale survey of δ(15)N, δ(13)C, tissue-N in seaweeds was conducted using samples from 17 sampling points at two sites (Grandcamp-Maisy (GM), Courseulles/Mer (COU)) along the French coast of the English Channel in 2012 and 2013. Partial triadic analysis was performed on the parameter data sets and revealed the functioning of three areas: one estuary (EstA) and two rocky areas (GM(*), COU(*)). In contrast to oceanic and anthropogenic reference points similar temporal dynamics characterized δ(15)N signatures and N contents at GM(*) and COU(*). Nutrient dynamics were similar: the N-concentrations in seawater originated from the River Seine and local coastal rivers while P-concentrations mainly from these local rivers. δ(15)N at GM(*) were linked to turbidity suggesting inputs of autochthonous organic matter from large-scale summer seaweed beachings made up of a mixture of Rhodophyta, Phaeophyta and Chlorophyta species. This study highlights the coupling between seaweed beachings and nitrogen sources of intertidal macroalgae.

}, issn = {1879-3363}, doi = {10.1016/j.marpolbul.2015.06.010}, author = {St{\'e}phanie Lemesle and Isabelle Mussio and Anne-Marie Rusig and Florence Menet-N{\'e}d{\'e}lec and Pascal Claquin} } @article {4159, title = {Production of exopolymers (EPS) by cyanobacteria: impact on the carbon-to-nutrient ratio of the particulate organic matter}, journal = {Aquatic Ecology}, year = {2015}, pages = {1-16}, abstract = {

Freshwater cyanobacteria can produce large amount of mucilage, particularly during large blooms. The production of these carbon-rich exopolymers (EPS) should influence the carbon-to-nutrient ratios of the organic matter (OM), which are regularly used as a proxy for the herbivorous food quality. However, little is known about the consequences of EPS production on the carbon-to-nutrient ratio of the OM. Two EPS forms can be distinguished: the free fraction composed of soluble extracellular polymeric substances (S-EPS) and the particulate fraction corresponding to the transparent exopolymer particles (TEP). The aim of the study was to determine whether the TEP and S-EPS productions by cyanobacteria influence the carbon-to-nutrient ratios of the particulate OM (POM). Five cyanobacteria species were grown in batch culture and characterized in terms of photosynthetic activity, EPS production, and C, N, P
contents. The variability in EPS production was compared with the variability in stoichiometry of the POM. Most of cyanobacteria live in association with
heterotrophic bacteria (HB) within the mucilage. The effect of the presence/absence of HB on EPS production and the carbon-to-nutrient ratios of the POM was also characterized for the cyanobacteria Microcystis aeruginosa. We showed that TEP production increased the carbon-to-nutrient ratios of the POM in
the absence of HB, while the stoichiometry did not significantly change when HB were present. The C:N ratio of the POM decreased with production of\  S-EPS by the five species. Lastly, the three colonial species (Chroococcales) tend to produce more TEP than the two filamentous species (Oscillatoriales), with the two picocyanobacteria being the most productive of both TEP and S-EPS.

}, author = {Pannard, A and P{\'e}dronon, J and Bormans, M and Briand, E and Pascal Claquin and Yvan Lagadeuc} } @article {3412, title = {Diversity structure of phytoplankton communities and primary productivity in a temperate epicontinental sea }, journal = {Marine Ecology Progress Series}, volume = {505}, year = {2014}, pages = {49-64}, abstract = {The dynamics of the phytoplankton assemblage, the physical, chemical and biological parameters, and primary productivity and production were monitored in the central English Channel along a transect between Ouistreham and Portsmouth from January to December 2010. The spatial patterns of the phytoplankton assemblage were controlled by the hydrological characteristics of the water masses, and the annual structure of the phytoplankton assemblage was characteristic of the central English Channel and was controlled by seasonality. The spring bloom was dominated by a single species, Chaetoceros socialis, and associated with low microphytoplankton evenness and Shannon-Wiener indices, whereas the evenness index was high from late spring to winter and associated with the proliferation of pico- and nanophytoplankton cells. We identified 2 species responsible for harmful algal blooms, Phaeocystis globosa, which dominated the community in the northern part of the Seine Bay in May, and Lepidodinium chlorophorum, which dominated the community near the French coast in September. We examined the relationship between microphytoplankton diversity and maximum primary production and productivity. We found a negative parabolic relationship between the diversity indices (evenness and Shannon-Wiener) and maximum primary production, and a positive parabolic relationship between the number of taxa (richness) and maximum primary production. However, we found no relationship between maximum productivity and the evenness or richness indices. High levels of productivity were measured during the increasing abundance of pico and nanophytoplankton cells, highlighting the importance of taking the dominant functional group into account, rather than the degree of diversity, when explaining the level of productivity.}, keywords = {English Channel, Phytoplankton diversity, primary production, Productivity}, author = {Napol{\'e}on, C and Fiant, Liliane and Raimbault, V and Riou, P and Pascal Claquin} } @article {3414, title = {Effects of CO2, nutrients and light on coastal plankton: II. Metabolic rates. Aquatic Biology}, journal = {Aquatic Biology}, volume = {22}, year = {2014}, month = {11/20/14}, pages = {43-57}, abstract = {We conducted a microcosm experiment aimed at studying the interactive effects of high CO2, nutrient loading and irradiance on the metabolism of a planktonic community sampled in the Western Mediterranean near the coast of M{\'a}laga. Changes in the metabolism of phytoplankton and bacterioplankton were observed for 7 d under 8 treatment conditions, representing the full factorial combinations of 2 levels each of CO2, nutrient concentration and solar radiation exposure. The initial plankton sample was collected at the surface from a stratified water column, indicating that phytoplankton were naturally acclimated to high irradiance and low nutrient concentrations. Nutrient addition combined with high irradiance resulted in a significant increase in primary production. Nitrate uptake by phytoplankton was also stimulated under high nutrient conditions. High nutrients, high irradiance and the combination of low CO2 and high irradiance positively affected bacterial production. Light was the main factor affecting the respiration rates of the community, which were higher at the high light level. After 7 d of incubation, nutrient loading was the only factor that significantly affected the amount of particulate organic carbon (POC) accumulated in the microcosms. Therefore, the changes in metabolic rates produced at high CO2 had no effect on net production of particulate organic matter. If these results are extrapolated to the natural environment, it could be hypothesized that high levels of CO2 will have a limited impact on biological pump activity in the northern Alboran Sea since it is assumed that POC export towards deeper layers determines the potential for carbon sequestration.}, author = {Mercado, J. M. and Sobrino, C and Neale, P.J. and Segovia, M. and Reul, A. and Amorim, A.L. and Carrillo, P and Pascal Claquin and Cabrerizo, M.J and Le{\'o}n, P. and Lorenzo, M.R and Medina, J. M. and Montecino, V. and Napol{\'e}on, C and Prasil, 0. and Putzeys, S and Salles, S and Yebra, L} } @article {3413, title = {Interactive effects of irradiance and temperature on growth and domoic acid production of the toxic diatom Pseudo-nitzschia australis (Bacillariophyceae)}, journal = {Harmful Algae}, volume = {39}, year = {2014}, pages = {232-241}, abstract = {The influence of temperature and light on the growth, physiology and domoic acid (DA) production of the pennate toxic diatom Pseudo-nitzschia australis isolated from the English Channel was studied in semicontinuous culture. The effects of eight irradiances (35{\textendash}400 mmol photons m2 s-1) and a temperature gradient (3.5{\textendash}25.5 8C) were investigated. The highest growth rates (0.47{\textendash}0.83 d-1) were observed between 18.6 and 13.5 8C, with an optimum irradiance for growth at 100 mmol photons m2 s-1. A decrease in the optimum growth temperature was observed with an increase in irradiance. Cell chlorophyll a content decreased at both low and high extreme temperatures and high irradiances. Stable and high values of Fv/Fm ratios below 21.8C highlight the great acclimation capacity of P. australis, which may explain its wide biogeographic distribution. The strain studied produced DA without nutrient limitation and during exponential growth although at lower levels than in other studies (0.15{\textendash} 2.0 pg DA cell-1). Results underline the importance of light{\textendash}temperature interactions for growth and DA production. Toxin production increased with increasing temperature and light, and DA production increased exponentially with the growth rate. These results show that DA is not only produced under nutrient stress or by unhealthy cells in P. australis. This study underlines the need to take the ability of P. australis to produce DA during the exponential growth into consideration to understand the link between toxin production and bloom dynamics. These results will not only help explore the processes involved, but also help parameterize future models of growth and DA production especially for P. australis.}, keywords = {Domoic acid, Growth Irradiance, Pseudo-nitzschia australis, Temperature}, author = {Thorel, Maxine and Juliette Fauchot and Morelle, J{\'e}r{\^o}me and Raimbault, V and Le Rou, B and Miossec, C and Kientz-Bouchard, V and Pascal Claquin} }