@article{fdi:010053601,
  title = {{E}ffect of seasonal biogenic silica variations on dissolved silicon fluxes and isotopic signatures in the {C}ongo {R}iver},
  author = {{H}ughes, {H}.{J}. and {S}ondag, {F}rancis and {C}ocquyt, {C}. and {L}araque, {A}lain and {P}andi, {A}. and {A}ndr{\'e}, {L}. and {C}ardinal, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e report 2 yr of monthly data from the {C}ongo {R}iver (the second largest river in the world) on dissolved silicon concentrations, biogenic silica particle concentrations, isotopic signatures of dissolved silicon, and biogenic siliceous particle counts. {D}iatoms predominated in the biogenic silica fraction, especially during low flow; phytoliths and sponge spicules were more abundant than diatoms only during the rainy season, when biogenic silica fluxes are low. {B}iological processes dominated the seasonal variations of the dissolved delta {S}i-30 ratio that are superimposed on a constant abiotic delta {S}i-30 value of +0.70 parts per thousand +/- 0.05 parts per thousand throughout the year. {T}he measured biogenic silica concentration is less than the amount required to explain the monthly variations of dissolved delta {S}i-30 signatures. {W}e use these signatures and a {R}ayleigh isotopic fractionation model to calculate that 82% +/- 7% of the diatoms produced each month would be exported out of the water column, probably through settling in the {M}alebo {P}ool or further upstream. {T}he uptake of dissolved silicon by diatoms during low water flow periods could explain the absence of the dilution effect observed for the other major elements. {A}nnual {S}i export to the estuary is 1.17 x 10(10) mol yr(-1) in the form of biogenic silica and 2.23 x 10(11) mol yr(-1) in dissolved {S}i form, with a mean dissolved delta {S}i-30 of +0.96 parts per thousand +/- 0.27 parts per thousand. {P}hytoliths make only a minor contribution to the annual biogenic silica flux, and dissolved {S}i fluxes predominate over biogenic {S}i fluxes.},
  keywords = {{CONGO} {COURS} {D}'{EAU}},
  booktitle = {},
  journal = {{L}imnology and {O}ceanography},
  volume = {56},
  numero = {2},
  pages = {551--561},
  ISSN = {0024-3590},
  year = {2011},
  DOI = {10.4319/lo.2011.56.2.0551},
  URL = {https://www.documentation.ird.fr/hor/fdi:010053601},
}