@article{fdi:010074151,
  title = {{N}itrogen and phosphorus recycling mediated by copepods and response of bacterioplankton community from three contrasting areas in the western tropical {S}outh {P}acific (20 degrees {S})},
  author = {{V}aldes, {V}. and {C}arlotti, {F}. and {E}scribano, {R}. and {D}onoso, {K}. and {P}agano, {M}arc and {M}olina, {V}. and {F}ernandez, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{Z}ooplankton play a key role in the regeneration of nitrogen and phosphorus in the ocean through grazing and metabolism. {T}his 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 {F}ebruary-3 {A}pril 2015) at three longduration stations ({LD}). {T}wo {LD} stations were located in the {M}elanesian {A}rchipelago region ({MA}; {LD} {A} and {LD} {B}) and one in the {S}outh {P}acific {G}yre ({SG}; {LD} {C}), which represent oligotrophic and ultra-oligotrophic regions respectively. {A}t each station, on-board microcosm 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. {I}n the presence of copepods, ammonium and dissolved organic nitrogen showed a significant increase compared to a control in two situations: in ammonium concentration (rate: 0.29 mu mol {L}-1 h(-1) after 4 h of incubation) in {LD} {C} and in dissolved organic nitrogen concentration (rate: 2.13 mu mol {L}-1 h(-1) after 0.5 h of incubation) in {LD} {A}. {I}n 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 the active bacterial community was observed for the experiments in {LD} {A} and {LD} {B}, which were mainly characterized by an increase in {A}lteromonadales and {SAR}11, respectively, and linked with changes in nutrient concentrations. {I}n the experiment performed in {LD} {C}, both groups increased but at different periods of incubation. {A}lteromonadales increased between 1 and 2 h after the beginning of the experiment, and {SAR} 11 at the end of incubation. {O}ur 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 timescales, depending on the initial environmental conditions and on their community composition. {T}hese processes can significantly contribute to nutrient recycling and regenerated production in the photic zone of ultra-oligotrophic and oligotrophic oceanic regions.},
  keywords = {{ZONE} {TROPICALE} ; {PACIFIQUE} {SUD}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {15},
  numero = {20},
  pages = {6019--6032},
  ISSN = {1726-4170},
  year = {2018},
  DOI = {10.5194/bg-15-6019-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074151},
}