@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 {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} }