 |
| Titel |
Enhanced viral production and virus-mediated mortality of bacterioplankton in a natural iron-fertilized bloom event above the Kerguelen Plateau |
| VerfasserIn |
A. Malits, U. Christaki, I. Obernosterer, M. G. Weinbauer |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 23 ; Nr. 11, no. 23 (2014-12-08), S.6841-6853 |
| Datensatznummer |
250117720
|
| Publikation (Nr.) |
 copernicus.org/bg-11-6841-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Above the Kerguelen Plateau in the Southern Ocean natural iron fertilization
sustains a large phytoplankton bloom over 3 months during austral
summer. During the KEOPS1 project (KErguelen Ocean and Plateau compared
Study1) we sampled this phytoplankton bloom during its declining phase along
with the surrounding high-nutrient–low-chlorophyll (HNLC) waters to study the effect of natural iron
fertilization on the role of viruses in the microbial food web. Bacterial
and viral abundances were 1.7 and 2.1 times, respectively, higher within the
bloom than in HNLC waters. Viral production and virus-mediated mortality of
bacterioplankton were 4.1 and 4.9 times, respectively, higher in the bloom,
while the fraction of infected cells (FIC) and the fraction of lysogenic
cells (FLC) showed no significant differences between environments. The
present study suggests viruses to be more important for bacterial mortality
within the bloom and dominate over grazing of heterotrophic nanoflagellates
(HNFs) during the late bloom phase. As a consequence, at least at a late
bloom stage, viral lysis shunts part of the photosynthetically fixed carbon
in iron-fertilized regions into the dissolved organic matter (DOM) pool with
potentially less particulate organic carbon transferred to larger members of
the food web or exported. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|