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Environmental characteristics of Agulhas rings affect interocean plankton transport

05/22/2015
Science
348 (6237) pp. 1261447

Type

Article dans des revues

Authors

Villar Emilie
Farrant Gregory
Follows Michael
Garczarek Laurence
Speich Sabrina
Audic Stéphane
Bittner Lucie
Blanke Bruno
Brum Jennifer R
Brunet Christophe
Casotti Raffaella
Chase Alison
Dolan John R
d'Ortenzio Fabrizio
Gattuso Jean-Pierre
Grima Nicolas
Guidi Lionel
Hill Christopher N
Jahn Oliver
Jamet Jean-Louis
Le Goff Hervé
Lepoivre Cyrille
Malviya Shruti
Pelletier Eric
Romagnan Jean-Baptiste
Roux Simon
Santini Sébastien
Scalco Eleonora
Schwenck Sarah M
Tanaka Atsuko
Testor Pierre
Vannier Thomas
Vincent Flora
Zingone Adriana
Dimier Céline
Picheral Marc
Searson Sarah
Kandels-Lewis Stefanie
Tara Oceans Coordinators
Acinas Silvia G.
Bork Peer
Boss Emmanuel
De Vargas Colomban
Gorsky Gaby
Ogata Hiroyuki
Pesant Stéphane
Sullivan Matthew B
Sunagawa Shinichi
Wincker Patrick
Karsenti Eric
Bowler Chris
Not Fabrice
Hingamp Pascal
Iudicone Daniele

Agulhas rings provide the principal route for ocean waters to circulate from the Indo-Pacific to the Atlantic basin. Their influence on global ocean circulation is well known, but their role in plankton transport is largely unexplored. We show that, although the coarse taxonomic structure of plankton communities is continuous across the Agulhas choke point, South Atlantic plankton diversity is altered compared with Indian Ocean source populations. Modeling and in situ sampling of a young Agulhas ring indicate that strong vertical mixing drives complex nitrogen cycling, shaping community metabolism and biogeochemical signatures as the ring and associated plankton transit westward.

The peculiar local environment inside Agulhas rings may provide a selective mechanism contributing to the limited dispersal of Indian Ocean plankton populations into the Atlantic.