Exploring controls on the timing of the phytoplankton bloom in western Baffin Bay, Canadian Arctic

• Main Authors: Benoît-Gagné, Maxime, Dutkiewicz, Stephanie, Deschepper, Inge, Dufresne, Christiane, Dumont, Dany, Larouche, Raphaël, Mémery, Laurent, Olivier, Gaëtan, Maps, Frédéric
• Other Authors: Université Laval Québec (ULaval), Takuvik International Research Laboratory, Université Laval Québec (ULaval)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric and Planetary Sciences MIT, Cambridge (EAPS), Massachusetts Institute of Technology (MIT), Institut Maurice-Lamontagne, Pêches et Oceans Canada, Institut des Sciences de la MER de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), 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), CNES (project #131425), French Arctic Initiative, Fondation Total, CSA, LEFE and IPEV (project #1164), Sentinel North, Université Laval, Weston Family Foundation, NASA Earth Science Division’s Interdisciplinary Science (IDS) program (grant number 80NM0018D0004), NSERC Discovery Grants (RGPIN-2013-402257, RGPIN-2019-06563), NSERC Discovery Grants (RGPIN-2014-05433, RGPIN-2021-03876), SMAART program through the Collaborative Research and Training Experience program (CREATE) of the NSERC, ANR-14-CE01-0017,Green Edge,Productivité biologique dans l'Océan Arctique: réponse passée, présente et future aux fluctuations climatiques, et impacts sur les flux de carbone, le réseau trophique et les communautés humaines locales(2014)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; Arctic; Arctic Ocean; Baffin Bay; Baffin; Climate change; Phytoplankton; Sea ice
• Online Access: https://hal.science/hal-04695952; https://hal.science/hal-04695952/document; https://hal.science/hal-04695952/file/EIC-accepted_manuscript_clean.pdf

International audience In the Arctic Ocean the peak of the phytoplankton bloom occurs around the period of sea ice break-up. Climate change is likely to impact the bloom phenology and its crucial contribution to the production dynamics of Arctic marine ecosystems. Here we explore and quantify controls on the timing of the spring bloom using a one-dimensional biogeochemical/ecosystem model configured for coastal western Baffin Bay. The model reproduces the observations made on the phenology and the assemblage of the phytoplankton community from an ice camp in the region. Using sensitivity experiments, we found that two essential controls on the timing of the spring bloom were the biomass of phytoplankton before bloom initiation and the light under sea ice before sea ice break-up. The level of nitrate before bloom initiation was less important. The bloom peak was delayed up to 20 days if the overwintering phytoplankton biomass was too low. This result highlights the importance of phytoplankton survival mechanisms during polar winter to the pelagic ecosystem of the Arctic Ocean and the spring bloom dynamics.