@article{fdi:010085161,
  title = {{A}ctivity and distribution of diazotrophic communities across the {C}ape {V}erde {F}rontal {Z}one in the {N}ortheast {A}tlantic {O}cean},
  author = {{H}allstrom, {S}. and {B}enavides, {M}ar and {S}alamon, {E}. {R}. and {A}ristegui, {J}. and {R}iemann, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e investigated dinitrogen ({N}-2) fixation activity and diazotroph community composition across the {C}ape {V}erde {F}rontal {Z}one ({CVFZ}), from photic epipelagic waters (0-200 m) to aphotic meso- (200-1000 m) and bathypelagic (> 1000 m) waters. {T}he highest {N}-2 fixation rates of 4.1 +/- 2.2 nmol {N} l(- 1) day(- 1) and 7.8 +/- 2.3 nmol {N} l(- 1) day(- 1) were in epipelagic waters south of the front. {W}e detected aphotic {N}-2 fixation in 5 out of 32 samples, primarily south of the front, and sporadically down to 3,000 m, with rates ranging from 0.03 +/- 0.01 nmol {N} l(- 1) day(- 1) to 0.07 +/- 0.01 nmol {N} l(- 1) day(- 1). {C}yanobacteria dominated the diazotroph community and nitrogenase gene (nif{H}) expression profiles in surface waters and, surprisingly, in aphotic waters. {T}he detection of cyanobacterial nif{H} genes by {DNA} sequencing and quantitative {PCR} in the aphotic zone, together with nif{H} expression in meso- and bathypelagic waters, indicates a downward flux of metabolically active cyanobacteria, and points to a contribution to the observed aphotic {N}-2 fixation rates. {I}n the photic zone, {UCYN}-{A} dominated north of the front, whereas {T}richodesmium was mainly found in the southern region. {H}owever, our results also show that cross-frontal advection of cyanobacterial diazotrophs can occur via intrusions of surface water. {S}alinity, temperature, and mixed layer depth were the main determinants of the diazotroph composition and distribution of the key cyanobacteria. {T}hus, the front appeared to act as a dynamic barrier controlling the distribution of cyanobacterial diazotrophs.},
  keywords = {{N}-2 fixation ; {U}pwelling ; {N}ortheast {A}tlantic ; {E}astern boundary upwelling system ; {T}richodesmium ; {UCYN}-{A} ; {ATLANTIQUE} ; {ATLANTIQUE} {NORD} ; {AFRIQUE} {DE} {L}'{OUEST} ; {CAP} {VERT} ; {CAP} {BLANC} ; {CAP} {VERT} {ILES}},
  booktitle = {},
  journal = {{B}iogeochemistry},
  volume = {[{E}arly access]},
  numero = {},
  pages = {[19 p.]},
  ISSN = {0168-2563},
  year = {2022},
  DOI = {10.1007/s10533-022-00940-w},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085161},
}