Insights into global diatom distribution and diversity in the world's ocean

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Malviya, Shruti, Scalco, Eleonora, Audic, Stephane, Vincenta, Flora, Veluchamy, Alaguraj, Poulain, Julie, Wincker, Patrick, Iudicone, Daniele, Vargas, Colomban, De, Bittner, Lucie, Zingone, Adriana, Bowler, Chris
• Other Authors: Analyse des Données à Haut Débit en Génomique (ADHDG), Evolution Paris Seine, Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Centre National de la Recherche Scientifique (CNRS), Ministero dell'Istruzione dell'Universit a e della Ricerca RITMARE project, Centre National de la Recherche Scientifique, Agnes b., Veolia Environment Foundation, Region Bretagne, World Courier, Illumina, Cap L'Orient, Electricite de France (EDF) Foundation EDF Diversiterre, Fondation pour la Recherche sur la Biodiversite, Prince Albert II de Monaco Foundation, Etienne Bourgois, Groupement de Recherche GDR3280, Tara schooner, European Molecular Biology Laboratory, Genoscope/Commissariat a l'Energie Atomique, French Government ``Investissements d'Avenir'' ANR-11-BTBR-0008, ANR-10-INBS-09-08, ANR-10-LABX-54, Paris Sciences et Lettres (PSL star ) Research University ANR-11-IDEX-0001-02, Agence Nationale de la Recherche (ANR) ANR-10-INBS-09-08, ANR-09-BLAN-0348, ANR-09-GENM-031, ANR-2010-1709-01, European Union 287589, European Research Council 294823
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: biodiversity; diatoms; metabarcoding; Tara Oceans; choke points; [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry; Molecular Biology/Genomics [q-bio.GN]; Drake Passage; Southern Ocean
• Online Access: https://hal.science/hal-01545320; https://doi.org/10.1073/pnas.1509523113

International audience Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of similar to 12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 size-fractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.