TY - JOUR T1 - Dynamics of phytoplankton diversity structure and primary productivity in the English Channel A1 - Napoleon,Camille A1 - Fiant,Liliane A1 - Raimbault,Virginie A1 - Riou,Philippe A1 - Claquin,Pascal AD - Univ Caen Basse Normandie, UMR BOREA, F-14032 Caen, France. AD - UCBN, UPMC, MNHN, UMR BOREA,CNRS 7208,IRD 207, F-14032 Caen, France. AD - IFREMER, Lab Environm Ressources Normandie, F-14520 Port En Bessin, France. UR - https://archimer.ifremer.fr/doc/00198/30964/ DO - 10.3354/meps10772 KW - Phytoplankton diversity KW - Primary production KW - Productivity KW - English Channel N2 - 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. Y1 - 2014 PB - Inter-research JF - Marine Ecology Progress Series SN - 0171-8630 VL - 505 SP - 49 EP - 64 ID - 30964 ER -