@article{fdi:010084676,
  title = {{A}nomalously high abundance of {C}rocosphaera in the {S}outh {P}acific {G}yre},
  author = {{B}enavides, {M}ar and {C}affin, {M}. and {D}uhamel, {S}. and {F}oster, {R}. {A}. and {G}rosso, {O}. and {G}uieu, {C}. and {V}an {W}ambeke, {F}. and {B}onnet, {S}ophie},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e find diazotrophically active {C}rocosphaera in the clearest waters of the world's oceans. {T}he unicellular diazotrophic cyanobacterium {C}rocosphaera contributes significantly to fixed nitrogen inputs in the oligotrophic ocean. {I}n the western tropical {S}outh {P}acific {O}cean ({WTSP}), these diazotrophs abound thanks to the phosphorus-rich waters provided by the {S}outh {E}quatorial {C}urrent, and iron provided aeolian and subsurface volcanic activity. {E}ast of the {WTSP}, the {S}outh {P}acific {G}yre ({SPG}) harbors the most oligotrophic and transparent waters of the world's oceans, where only heterotrophic diazotrophs have been reported before. {H}ere, in the {SPG}, we detected unexpected accumulation of {C}rocosphaera at 50 m with peak abundances of 5.26 x 10(5) nif{H} gene copies l(-1). {T}he abundance of {C}rocosphaera at 50 m was in the same order of magnitude as those detected westwards in the {WTSP} and represented 100% of volumetric {N}-2 fixation rates. {T}his accumulation at 50 m was likely due to a deeper penetration of {UV} light in the clear waters of the {SPG} being detrimental for {C}rocosphaera growth and {N}-2 fixation activity. {N}utrient and trace metal addition experiments did not induce any significant changes in {N}-2 fixation or {C}rocosphaera abundance, indicating that this population was not limited by the resources tested and could develop in high numbers despite the oligotrophic conditions. {O}ur findings indicate that the distribution of {C}rocosphaera can extend into subtropical gyres and further understanding of their controlling factors is needed.},
  keywords = {{C}rocosphaera ; oligotrophic ; diazotrophs ; cyanobacteria ; {PACIFIQUE} ; {PACIFIQUE} {SUD}},
  booktitle = {},
  journal = {{FEMS} {M}icrobiology {L}etters},
  volume = {369},
  numero = {1},
  pages = {fnac039 [7 ]},
  ISSN = {0378-1097},
  year = {2022},
  DOI = {10.1093/femsle/fnac039},
  URL = {https://www.documentation.ird.fr/hor/fdi:010084676},
}