@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 {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} }