Need for focus on microbial species following ice melt and changing freshwater regimes in a Janus Arctic Gateway

• Published in: Scientific Reports
• Main Authors: Joli, Nathalie, Gosselin, Michel, Ardyna, Mathieu, Babin, Marcel, Florence Onda, Deo, Tremblay, Jean-Éric, Lovejoy, Connie
• Other Authors: Institut de Biologie Intégrative et des Systèmes Québec (IBIS), Takuvik Joint International Laboratory ULAVAL-CNRS, Université Laval Québec (ULaval)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université du Québec à Rimouski (UQAR), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; Arctic; Canada; Ellesmere Island; Greenland; Janus; Nares; Nares strait; North Atlantic; Phytoplankton
• Online Access: https://hal.sorbonne-universite.fr/hal-01829749; https://hal.sorbonne-universite.fr/hal-01829749/document; https://hal.sorbonne-universite.fr/hal-01829749/file/s41598-018-27705-6.pdf; https://doi.org/10.1038/s41598-018-27705-6

International audience Oceanic gateways are sensitive to climate driven processes. By connecting oceans, they have a global influence on marine biological production and biogeochemical cycles. The furthest north of these gateways is Nares Strait at the top of the North Water between Greenland and Ellesmere Island (Canada). This gateway is globally beneficial, first by supporting high local mammal and bird populations and second with the outflow of phosphate-rich Arctic waters fueling the North Atlantic spring bloom. Both sides of the North Water are hydrologically distinct with counter currents that make this Arctic portal a Janus gateway, after Janus, the Roman god of duality. We examined oceanographic properties and differences in phytoplankton and other protist communities from the eastern and western sides of the North Water (latitude 76.5°N) and found that species differed markedly due to salinity stratification regimes and local hydrography. Typical Arctic communities were associated with south flowing currents along the Canadian side, while potentially noxious Pseudo-nitzschia spp. were dominant on the Greenland side and associated with greater surface freshening from ice melt. This susceptibility of the Greenland side to Pseudo-nitzschia spp. blooms suggest that monitoring species responses to climate mediated changes is needed.