Skip to Main content Skip to Navigation
New interface
Journal articles

Planktonic dinitrogen fixation along a longitudinal gradient across the Mediterranean Sea during the stratified period (BOUM cruise)

Abstract : This study provides extensive data on planktonic N-2 fixation rates across the whole Mediterranean Sea. They show that N-2 fixation occurs in Mediterranean waters during the stratification period, with a clear decreasing trend from the oligotrophic western basin (10-76 mu mol m(-2) d(-1)) to the ultra oligotrophic eastern basin (0-0.4 mu mol m(-2) d(-1)). Highest rates are measured in the less oligotrophic western basin, between the surface and 75 m-depth, where 45 to 75% of N-2 fixation are found within the picoplanktonic fraction (<3 mu m). While the biogeochemical impact of N-2 fixation in the eastern basin seems negligible, N-2 fixation is able to sustain up to 35% of new primary production during the stratified period in the western basin. These data disagree with indirect estimates of N-2 fixation based on geochemical tracers and nutrient budgets, which indicates that N-2 fixation increases with increasing N:P ratios and decreasing stable N isotopic signature of particulate organic nitrogen and NO3- from west to east. These results finally point out the need to assess N-2 fixation at a higher temporal resolution in order to better understand the diazotrophs' dynamic under contrasted biogeochemical conditions.
Document type :
Journal articles
Complete list of metadata

Cited literature [61 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-00724468
Contributor : Thierry Pin Connect in order to contact the contributor
Submitted on : Monday, August 3, 2020 - 1:42:06 PM
Last modification on : Thursday, January 27, 2022 - 4:54:01 AM
Long-term archiving on: : Monday, November 30, 2020 - 1:39:31 PM

File

bg-8-2257-2011.pdf
Publication funded by an institution

Licence


Distributed under a Creative Commons Attribution - NoDerivatives 4.0 International License

Identifiers

Citation

Sophie Bonnet, Olivier Grosso, Thierry Moutin. Planktonic dinitrogen fixation along a longitudinal gradient across the Mediterranean Sea during the stratified period (BOUM cruise). Biogeosciences, 2011, 8 (8), pp.2257-2267. ⟨10.5194/bg-8-2257-2011⟩. ⟨hal-00724468⟩

Share

Metrics

Record views

161

Files downloads

27