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| Titel |
Modelling the impact of riverine DON removal by marine bacterioplankton on primary production in the Arctic Ocean |
| VerfasserIn |
V. Le Fouest, M. Manizza, B. Tremblay, M. Babin |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 11 ; Nr. 12, no. 11 (2015-06-04), S.3385-3402 |
| Datensatznummer |
250117967
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| Publikation (Nr.) |
 copernicus.org/bg-12-3385-2015.pdf |
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| Zusammenfassung |
| The planktonic and biogeochemical dynamics of the Arctic shelves exhibit a
strong variability in response to Arctic warming. In this study, we employ a
biogeochemical model coupled to a pan-Arctic ocean–sea ice model (MITgcm) to
elucidate the processes regulating the primary production (PP) of
phytoplankton, bacterioplankton (BP), and their interactions. The model
explicitly simulates and quantifies the contribution of usable dissolved
organic nitrogen (DON) drained by the major circum-Arctic rivers to PP and BP
in a scenario of melting sea ice (1998–2011). Model simulations suggest
that, on average between 1998 and 2011, the removal of usable riverine
dissolved organic nitrogen (RDON) by bacterioplankton is responsible for a
~ 26% increase in the annual BP for the whole Arctic Ocean. With
respect to total PP, the model simulates an increase of ~ 8% on an
annual basis and of ~ 18% in summer. Recycled ammonium is
responsible for the PP increase. The recycling of RDON by bacterioplankton
promotes higher BP and PP, but there is no significant temporal trend in the
BP : PP ratio within the ice-free shelves over the 1998–2011 period. This
suggests no significant evolution in the balance between autotrophy and
heterotrophy in the last decade, with a constant annual flux of RDON into the
coastal ocean, although changes in RDON supply and further reduction in
sea-ice cover could potentially alter this delicate balance. |
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