FN Archimer Export Format PT J TI Nitrogen and phosphorus recycling mediated by copepods in Western Tropical South Pacific BT AF Valdés, Valentina Carlotti, François Escribano, Ruben Donoso, Katty Pagano, Marc Molina, Veronica Fernandez, Camila AS 1:1,2;2:3;3:4,5;4:3;5:3;6:6;7:2,7,8; FF 1:;2:;3:;4:;5:;6:;7:; C1 Programa de Doctorado en Oceanografía, Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Sorbonne Universités, Banyuls sur Mer F-66650, France Aix-Marseille Univ, Universite de Toulon, CNRS, IRD, OSU PYTHEAS, Mediterranean Institute of Oceanography MIO, UM 110, 13288, Marseille, Cedex 09, France Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile Instituto Milenio de Oceanografía, Universidad de Concepción, Concepción, Chile Departamento de Biología and Programa de Biodiversidad, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Playa Ancha, Valparaíso, Chile FONDAP INCAR center (15110027), and PFB-31 COPAS Sur Austral program, Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile C2 UNIV CONCEPCION, CHILE UNIV PARIS 6, FRANCE UNIV AIX MARSEILLE, FRANCE UNIV CONCEPCION, CHILE UNIV CONCEPCION, CHILE UNIV PLAYA ANCHA, CHILE UNIV CONCEPCION, CHILE IDEAL, CHILE IN DOAJ IF 3.951 TC 0 UR https://archimer.ifremer.fr/doc/00422/53391/54253.pdf https://archimer.ifremer.fr/doc/00422/53391/54254.pdf https://archimer.ifremer.fr/doc/00422/53391/59630.pdf https://archimer.ifremer.fr/doc/00422/53391/59631.pdf LA English DT Article CR OUTPACE BO L'Atalante AB Zooplankton play a key role in the regeneration of nitrogen and phosphorus in the ocean through grazing and metabolism. This study investigates the role of the organic and inorganic nitrogen and phosphorus compounds released by copepods on biogeochemical processes and on the microbial community composition during the OUTPACE cruise (18 February–3 April 2015) at three long duration stations (LD). Two LD stations were located in the Melanesian Archipelago region (MA; LD A and LD B) and one in the South Pacific Gyre (SG; LD C), which represent oligotrophic and ultraoligotrophic regions respectively. At each station, microcosm onboard experiments were performed with locally sampled organisms, comprising a mix of epipelagic copepods fed with their natural food and then incubated along with wild microbial assemblages. In presence of copepods, ammonium and dissolved organic nitrogen showed a significant increase, compared to a control in two situations: in ammonium concentration (increasing rate: 0.29 μmol L−1 h−1 after 4 h of incubation) in LD C and in dissolved organic nitrogen concentration (rate: 2.13 μmol L−1 h−1 after 0.5 h of incubation) in LD A. In addition, during the three experiments, an enhanced remineralization (ammonification and nitrification) was observed when adding copepods compared to the controls. A shift in the composition of active bacterial community was observed for the experiments in LD A and LD B mainly characterized by an increase in Alteromonadales and SAR11, respectively and linked with changes in nutrient concentrations. In the experiment performed in LD C, both groups increased but at different periods of incubation, Alteromonadales between 1 and 2 h after the beginning of the experiment, and SAR 11 at the end of incubation. Finally, our experimental results in near in situ conditions, show that copepods can be a source of organic and inorganic compounds for bacterial communities, which respond to excretion pulses at different scales, depending on the initial environmental conditions and on their community composition. These processes can contribute significantly to nutrient recycling in the epipelagic ecosystem of ultra and oligotrophic oceanic regions. PY 2018 PD JAN SO Biogeosciences SN 1726-4170 PU Copernicus GmbH VL 15 IS 20 BP 6019 EP 6032 DI 10.5194/bg-2017-563 ID 53391 ER EF