Small phytoplankton dominate western North Atlantic biomass

• Published in: The ISME Journal
• Main Authors: Bolanos, Luis M., Karp-Boss, Lee, Choi, Chang Jae, Worden, Alexandra Z., Graff, Jason R., Haentjens, Nils, Chase, Alison P., Della Penna, Alice, Gaube, Peter, Morison, Françoise, Menden-Deuer, Susanne, Westberry, Toby K., O'Malley, Robert T., Boss, Emmanuel, Behrenfeld, Michael J., Giovannoni, Stephen J.
• Other Authors: Oregon State University (OSU), University of Maine, Monterey Bay Aquarium Research Institute (MBARI), Helmholtz Centre for Ocean Research Kiel (GEOMAR), Department of Botany and Plant Pathology, Applied Physics Laboratory Seattle (APL-UW), University of Washington Seattle, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Rhode Island (URI), This research was supported by NASA NAAMES grant no. NNX15AE70G. We thank Mark Dasenko and Oregon State University CGRB for amplicon library preparation and sequencing. We thank Captains A. Lund and D. Bergeron and R/V Atlantis crew. We thank the NAAMES community for their input. This study has been conducted using E.U. Copernicus Marine Service Information (CMEMS) and the Group for High Resolution Sea Surface Temperature (GHRSST) Multi-scale Ultra-high Resolution (MUR) SST data (obtained from the NASA EOSDIS Physical Oceanography Distributed Active Archive Center (PO.DAAC) at the Jet Propulsion Laboratory, Pasadena, CA). Phylogenetic analyses were supported in part by GBMF3788 and NSF DEB-1639033 to AZW. A. DP is grateful for the support of the Applied Physics Laboratory Science and Engineering Enrichment Development (SEED) fellowship and of funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 749591. We thank Mimi Lyon-Edmondson, Faith Hoyle, Emma Jourdain, Emma Dullaert and Gretchen Spencer for assistance with the classification of IFCB images.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: ACL; carbon; variability; community structure; diversity; ocean; time-series; fluorescence; export; lineages; nanoplankton; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Pinnacle; North Atlantic
• Online Access: https://hal.science/hal-02921158; https://hal.science/hal-02921158/document; https://hal.science/hal-02921158/file/s41396-020-0636-0.pdf; https://doi.org/10.1038/s41396-020-0636-0

WOS:000522382500001 International audience The North Atlantic phytoplankton spring bloom is the pinnacle in an annual cycle that is driven by physical, chemical, and biological seasonality. Despite its important contributions to the global carbon cycle, transitions in plankton community composition between the winter and spring have been scarcely examined in the North Atlantic. Phytoplankton composition in early winter was compared with latitudinal transects that captured the subsequent spring bloom climax. Amplicon sequence variants (ASVs), imaging flow cytometry, and flow-cytometry provided a synoptic view of phytoplankton diversity. Phytoplankton communities were not uniform across the sites studied, but rather mapped with apparent fidelity onto subpolar- and subtropical-influenced water masses of the North Atlantic. At most stations, cells \textless 20-mu m diameter were the main contributors to phytoplankton biomass. Winter phytoplankton communities were dominated by cyanobacteria and pico-phytoeukaryotes. These transitioned to more diverse and dynamic spring communities in which pico- and nano-phytoeukaryotes, including many prasinophyte algae, dominated. Diatoms, which are often assumed to be the dominant phytoplankton in blooms, were contributors but not the major component of biomass. We show that diverse, small phytoplankton taxa are unexpectedly common in the western North Atlantic and that regional influences play a large role in modulating community transitions during the seasonal progression of blooms.