Over het archief
Het OWA, het open archief van het Waterbouwkundig Laboratorium heeft tot doel alle vrij toegankelijke onderzoeksresultaten van dit instituut in digitale vorm aan te bieden. Op die manier wil het de zichtbaarheid, verspreiding en gebruik van deze onderzoeksresultaten, alsook de wetenschappelijke communicatie maximaal bevorderen.
Dit archief wordt uitgebouwd en beheerd volgens de principes van de Open Access Movement, en het daaruit ontstane Open Archives Initiative.
Basisinformatie over ‘Open Access to scholarly information'.
Mesopelagic organic carbon remineralization in the Kerguelen Plateau region tracked by biogenic particulate Ba
Jacquet, S.H.M.; Dehairs, F.; Savoye, N.; Obernosterer, I.; Christaki, U.; Monnin, C.; Cardinal, D. (2008). Mesopelagic organic carbon remineralization in the Kerguelen Plateau region tracked by biogenic particulate Ba. Deep-Sea Res., Part 2, Top. Stud. Oceanogr. 55(5-7): 868-879. dx.doi.org/10.1016/j.dsr2.2007.12.038
In: Deep-Sea Research, Part II. Topical Studies in Oceanography. Pergamon: Oxford. ISSN 0967-0645; e-ISSN 1879-0100, meer
|  |
| Trefwoord |
|
| Author keywords |
particulate biogenic barium; mesopelagic remineralization; iron |
| Auteurs | | Top |
- Jacquet, S.H.M., meer
- Dehairs, F., meer
- Savoye, N., meer
- Obernosterer, I.
|
- Christaki, U.
- Monnin, C.
- Cardinal, D., meer
|
|
| Abstract |
We report on the distribution of excess, non-lithogenic particulate barium (Ba), a proxy for twilight-zone remineralization of organic matter (OM), in the Kerguelen Plateau area during the late austral summer of 2005. This study was part of a broader investigation focusing on natural iron fertilization controlling the characteristic and recurrent phytoplankton blooms in the region. The Plateau area contrasted strongly with the off-shelf HNLC area. Plateau stations had quite high excess of Ba(xs) contents (up to 5000 pM) in surface waters (upper 150 m) that coincided with enhanced phytoplankton biomass. However, it had a lower mesopelagic (125-450 m) excess of biogenic Ba contents when compared to the off-shelf stations. Particulate excess Ba in the twilight zone (125-450 m depth layer) proved to be significantly set by the vertical distribution of bacterial activity, with higher particulate Ba contents in situations where significant bacterial activity extended deeper in the water column. These observations are in agreement with the role of excess biogenic particulate Ba as a proxy of twilight-zone OM remineralization. Using a transfer function established during earlier work, we calculated organic carbon remineralization rates and weighed these against other carbon fluxes (primary production, bacterial carbon demand), including carbon export from the 125-m horizon (234Th method). Off-shelf HNLC stations had a larger fraction of the organic carbon production exported and subsequently mineralized in the mesopelagic waters (125-450 m). Plateau stations had a smaller fraction of produced carbon exported, but this fraction appeared less prone to remineralization in the twilight zone and therefore had potential to reach the shallow (similar to 500 m) seafloor or to be exported off-shelf. Differences in trophic structure and in composition of the diatom community would explain the variability in twilight-zone remineralization processes and in transfer efficiency through the mesopelagic zone in the Kerguelen Plateau area. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
