4 results on '"Sara Sergi"'
Number of results to display per page
Search Results
2. Hydrothermal vents trigger massive phytoplankton blooms in the Southern Ocean
- Author
-
Mathieu Ardyna, Léo Lacour, Sara Sergi, Francesco d’Ovidio, Jean-Baptiste Sallée, Mathieu Rembauville, Stéphane Blain, Alessandro Tagliabue, Reiner Schlitzer, Catherine Jeandel, Kevin Robert Arrigo, and Hervé Claustre
- Subjects
Science - Abstract
Hydrothermal activity is recognized to be significant in regulating the dynamics of trace elements in the ocean. Here the authors report the first observational evidence of upwelled hydrothermally influenced deep waters stimulating massive phytoplankton blooms in the Southern Ocean.
- Published
- 2019
- Full Text
- View/download PDF
3. Interaction of the Antarctic Circumpolar Current With Seamounts Fuels Moderate Blooms but Vast Foraging Grounds for Multiple Marine Predators
- Author
-
Sara Sergi, Alberto Baudena, Cédric Cotté, Mathieu Ardyna, Stéphane Blain, and Francesco d’Ovidio
- Subjects
open ocean seamounts ,phytoplankton blooms ,Antarctic Circumpolar Current ,Lagrangian approach ,pelagic hotspots ,Science ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
In the Antarctic Circumpolar Current region of the Southern Ocean, the massive phytoplankton blooms stemming from islands support large trophic chains. Contrary to islands, open ocean seamounts appear to sustain blooms of lesser intensity and, consequently, are expected to play a negligible role in the productivity of this area. Here we revisit this assumption by focusing on a region of the Antarctic Circumpolar Current zone which is massively targeted by marine predators, even if no island fertilizes this area. By combining high resolution bathymetric data, Lagrangian analyses of altimetry-derived velocities and chlorophyll a observations derived from BGC-Argo floats and ocean color images, we reveal that the oligotrophic nature of the study region considered in low chlorophyll a climatological maps hides in reality a much more complex environment. Significant (chlorophyll a in excess of 0.6 mg/m3) phytoplankton blooms spread over thousands of kilometers and have bio-optical signatures similar to the ones stemming from island systems. By adopting a Lagrangian approach, we demonstrate that these moderate blooms (i) originate at specific sites where the Antarctic Circumpolar Current interacts with seamounts, and (ii) coincide with foraging areas of five megafauna species. These findings underline the ecological importance of the open ocean subantarctic waters and advocate for a connected vision of future conservation actions along the Antarctic Circumpolar Current.
- Published
- 2020
- Full Text
- View/download PDF
4. Massive Southern Ocean phytoplankton bloom fed by iron of possible hydrothermal origin
- Author
-
Anne-Carlijn Alderkamp, Hans van Haren, Patrick Laan, Casey M. S. Schine, Gert L. van Dijken, Kevin R. Arrigo, Loes J. A. Gerringa, Sara Sergi, Willem H. van de Poll, Stanford University, Foothill College, Royal Netherlands Institute for Sea Research (NIOZ), Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), University of Groningen [Groningen], Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Ocean Ecosystems
- Subjects
0106 biological sciences ,Chlorophyll ,Water mass ,010504 meteorology & atmospheric sciences ,Nitrogen ,Iron ,Oceans and Seas ,Science ,[SDV]Life Sciences [q-bio] ,General Physics and Astronomy ,Antarctic Regions ,01 natural sciences ,Algal bloom ,General Biochemistry, Genetics and Molecular Biology ,Hydrothermal circulation ,Article ,chemistry.chemical_compound ,Hydrothermal Vents ,14. Life underwater ,Biomass ,0105 earth and related environmental sciences ,Marine biology ,geography ,Multidisciplinary ,geography.geographical_feature_category ,010604 marine biology & hydrobiology ,Water ,Phosphorus ,General Chemistry ,Eutrophication ,Carbon ,Plume ,Kinetics ,Oceanography ,Ocean sciences ,chemistry ,Marine chemistry ,13. Climate action ,Ridge ,Phytoplankton ,Environmental science ,Bloom ,Hydrothermal vent - Abstract
Primary production in the Southern Ocean (SO) is limited by iron availability. Hydrothermal vents have been identified as a potentially important source of iron to SO surface waters. Here we identify a recurring phytoplankton bloom in the high-nutrient, low-chlorophyll waters of the Antarctic Circumpolar Current in the Pacific sector of the SO, that we argue is fed by iron of hydrothermal origin. In January 2014 the bloom covered an area of ~266,000 km2 with depth-integrated chlorophyll a > 300 mg m−2, primary production rates >1 g C m−2 d−1, and a mean CO2 flux of −0.38 g C m−2 d−1. The elevated iron supporting this bloom is likely of hydrothermal origin based on the recurrent position of the bloom relative to two active hydrothermal vent fields along the Australian Antarctic Ridge and the association of the elevated iron with a distinct water mass characteristic of a nonbuoyant hydrothermal vent plume., Primary productivity in the Southern Ocean plays an important role in the drawdown of atmospheric CO2, but phytoplankton growth is limited by iron. Here the authors show that iron from hydrothermal vents fuels massive phytoplankton blooms in the Southern Ocean that have recurred in the same location for decades.
- Published
- 2021
Catalog
Books, media, physical & digital resources
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.