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| Titel |
Distribution of calcifying and silicifying phytoplankton in relation to environmental and biogeochemical parameters during the late stages of the 2005 North East Atlantic Spring Bloom |
| VerfasserIn |
K. Leblanc, C. E. Hare, Y. Feng, G. M. Berg, G. R. DiTullio, A. Neeley, I. Benner, C. Sprengel, A. Beck, S. A. Sañudo-Wilhelmy, U. Passow, K. Klinck, J. M. Rowe, S. W. Wilhelm, C. W. Brown, D. A. Hutchins |
| 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 ; 6, no. 10 ; Nr. 6, no. 10 (2009-10-12), S.2155-2179 |
| Datensatznummer |
250004037
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| Publikation (Nr.) |
 copernicus.org/bg-6-2155-2009.pdf |
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| Zusammenfassung |
| The late stage of the North East Atlantic (NEA) spring bloom was
investigated during June 2005 along a transect section from 45 to 66° N
between 15 and 20° W in order to characterize the contribution of
siliceous and calcareous phytoplankton groups and describe their
distribution in relation to environmental factors. We measured several
biogeochemical parameters such as nutrients, surface trace metals, algal
pigments, biogenic silica (BSi), particulate inorganic carbon (PIC) or
calcium carbonate, particulate organic carbon, nitrogen and phosphorus (POC,
PON and POP, respectively), as well as transparent exopolymer particles
(TEP). Results were compared with other studies undertaken in this area
since the JGOFS NABE program. Characteristics of the spring bloom generally
agreed well with the accepted scenario for the development of the
autotrophic community. The NEA seasonal diatom bloom was in the late stages
when we sampled the area and diatoms were constrained to the northern part
of our transect, over the Icelandic Basin (IB) and Icelandic Shelf (IS).
Coccolithophores dominated the phytoplankton community, with a large
distribution over the Rockall-Hatton Plateau (RHP) and IB. The Porcupine
Abyssal Plain (PAP) region at the southern end of our transect was the
region with the lowest biomass, as demonstrated by very low Chla
concentrations and a community dominated by picophytoplankton. Early
depletion of dissolved silicic acid (DSi) and increased stratification of
the surface layer most likely triggered the end of the diatom bloom, leading
to coccolithophore dominance. The chronic Si deficiency observed in the NEA
could be linked to moderate Fe limitation, which increases the efficiency of
the Si pump. TEP closely mirrored the distribution of both biogenic silica
at depth and prymnesiophytes in the surface layer suggesting the
sedimentation of the diatom bloom in the form of aggregates, but the
relative contribution of diatoms and coccolithophores to carbon export in
this area still needs to be resolved. |
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