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| Titel |
Phytoplankton growth and microzooplankton grazing in the Chukchi borderland and Mendeleyev Ridge, Arctic Ocean |
| VerfasserIn |
Eun-Jin Yang, Dong-Jin Lee, Sung-Ho Kang |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077736
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| Zusammenfassung |
| During August and September 2012, we measured phytoplankton growth and
microzooplankton grazing rate in the Chukchi borderland and Mendeleyev Ridge using the
icebreaker R/V Araon. A variety of environmental condition and trophic condition were
encountered, from low chlorophyll-a (< 0.1 ug L-1) in the Chukchi borderland to
diatom bloom (maximum 17.1 ug L-1) in the southern part of Mendeleyev Ridge
which is characterized by high phytoplankton biomass driven by the influx of more
productive waters from the East Siberian Sea. The community of microzooplankton
was dominated by naked ciliates and heterotrophic dinoflagellates (HDF). Ciliates
dominated in low chlorophyll-a concentration sites and HDF dominated in high
chlorophyll-a concentration sites. Microzooplankton biomass and size structure
matched with the chlorophyll-a concentration and size-fraction. Grazing rate of
microzooplankton varied from 0.01 to 0.85 d-1, on average 0.34 d-1. Phytoplankton
growth rate varied from 0.09 to 0.76 d-1, on average 0.39 d-1. Phytoplankton
growth rate and microzooplankton grazing rate were relatively higher in the Chukchi
borderland than the Mendeleyev Ridge. Microzooplankton grazed from 10.3 to
122.8% (average 82.9%) of daily chlorophyll-a production and from 11.3 to 57.2%
(average 28.4%) of initial standing stock. In this study area, microzooplankton grazing
and phytoplankton growth were high compared to rates reported summer in the
other Arctic Ocean. The results suggest that microzooplankton were the major
consumers of primary production, and that their grazing is one of the most important
losses affecting the phytoplankton biomass during summer in the Arctic Ocean. |
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