@article{fdi:010092142,
  title = {{H}eterogeneity of nitrogen fixation in the mesopelagic zone of the {S}outh {C}hina {S}ea},
  author = {{W}u, {S}. {Q}. and {W}an, {X}. {S}. and {D}u, {M}. {G}. and {C}hen, {X}. {R}. and {S}elden, {C}. {R}. and {B}enavides, {M}ar and {B}onnet, {S}ophie and {L}{\¨o}scher, {C}. {R}. and {H}amersley, {M}. {R}. and {M}ulholland, {M}. {R}. and {Y}an, {X}. {L}. and {K}ao, {S}. {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}iological dinitrogen ({N}2) fixation, the energetically expensive conversion of {N}2 gas to ammonia, plays an essential role in balancing the nitrogen budget in the ocean. {A}ccumulating studies show detectable {N}2 fixation rates below the euphotic zone in various marine systems, revealing new insights of marine {N}2 fixation. {H}owever, the reported rates are highly variable and frequently fall close to detection limits, raising the question of the ubiquity and significance of {N}2 fixation in the global dark ocean. {U}sing highly sensitive isotopic labeling incubation including a set of control incubations, we confirm the occurrence of mesopelagic {N}2 fixation in the {S}outh {C}hina {S}ea. {I}nterestingly, we consistently observed that ca. 30% of samples show a significant elevation of 15{N} in the particulate nitrogen after incubation at most depths (200 - 1000 m). {A}lthough this approach does not allow accurate quantification of {N}2 fixation rates, our data suggest the occurrence of dark {N}2 fixation yet with highly heterogeneous signals in the mesopelagic zone of the {S}outh {C}hina {S}ea. {A} data compilation of reported {N}2 fixation in the global dark ocean further reveals that such heterogeneity has also been observed elsewhere, unveiling the ubiquitous heterogeneity in mesopelagic {N}2 fixation. {T}hus, we call for more observations to constrain mesopelagic {N}2 fixation budgets and to understand the underlying mechanism for such heterogeneity.},
  keywords = {nitrogen fixation ; mesopelagic zone ; heterogeneity ; {S}outh {C}hina {S}ea ; global compilation ; {MER} {DE} {CHINE}},
  booktitle = {},
  journal = {{F}rontiers in {M}arine {S}cience},
  volume = {11},
  numero = {},
  pages = {1495649 [13 p.]},
  year = {2024},
  DOI = {10.3389/fmars.2024.1495649},
  URL = {https://www.documentation.ird.fr/hor/fdi:010092142},
}