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| Titel |
Phytoplankton chlorophyll a biomass, composition, and productivity along a temperature and stratification gradient in the northeast Atlantic Ocean |
| VerfasserIn |
W. H. Poll, G. Kulk, K. R. Timmermans, C. P. D. Brussaard, H. J. Woerd, M. J. Kehoe, K. D. A. Mojica, R. J. W. Visser, P. D. Rozema, A. G. J. Buma |
| 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 ; 10, no. 6 ; Nr. 10, no. 6 (2013-06-25), S.4227-4240 |
| Datensatznummer |
250018309
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| Publikation (Nr.) |
 copernicus.org/bg-10-4227-2013.pdf |
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| Zusammenfassung |
| Relationships between sea surface temperature (SST, > 10 m) and vertical
density stratification, nutrient concentrations, and phytoplankton biomass,
composition, and chlorophyll a (Chl a) specific absorption were assessed in spring
and summer from latitudes 29 to 63° N in the northeast Atlantic
Ocean. The goal of this study was to identify relationships between
phytoplankton and abiotic factors in an existing SST and stratification
gradient. Furthermore, a bio-optical model was used to estimate productivity
for five phytoplankton groups. Nutrient concentration (integrated from
0 to 125 m) was inversely correlated with SST in spring and summer. SST was
also inversely correlated with near-surface (0–50 m) Chl a and productivity
for stratified stations. Near-surface Chl a and productivity showed exponential
relationships with SST. Chl a specific absorption and excess light
experiments indicated photoacclimation to lower irradiance in spring as
compared to summer. In addition, Chl a specific absorption suggested that
phytoplankton size decreased in summer. The contribution of cyanobacteria to
water column productivity of stratified stations correlated positively with
SST and inversely with nutrient concentration. This suggests that a rise in
SST (over a 13–23 °C range) stimulates productivity by
cyanobacteria at the expense of haptophytes, which showed an inverse
relationship to SST. At higher latitudes, where rising SST may prolong the
stratified season, haptophyte productivity may expand at the expense of
diatom productivity. Depth-integrated Chl a (0–410 m) was greatest in the
spring at higher latitudes, where stratification in the upper 200 m was
weakest. This suggests that stronger stratification does not necessarily
result in higher phytoplankton biomass standing stock in this region. |
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