|
|
|
|
|
| Lagaria, A.; Psarra, S.; Lefevre, D.; Van Wambeke, France; Courties, C.; Pujo-pay, M.; Oriol, L.; Tanaka, T.; Christaki, U.. |
| We examined the effects of nutrient additions on rates of (14)C-based particulate and dissolved primary production as well as O(2)-based metabolic rates in surface waters (8 m) of three anticyclonic eddies, located in the Western, Central and Eastern Mediterranean. Ship-board microcosm experiments employing additions of inorganic nitrogen (+N) and phosphorus (+P), alone and in combination (+NP), were conducted in June/July 2008 during the BOUM (Biogeochemistry from the Oligotrophic to the Ultra-oligotrophic Mediterranean) cruise. In all three experiments, particulate primary production was significantly stimulated by the additions of nitrogen (+N, +NP) while no effect was observed with the addition of phosphorus alone (+P). Percent extracellular release of... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24401/22418.pdf |
| |
|
|
| Popendorf, K. J.; Tanaka, T.; Pujo-pay, M.; Lagaria, A.; Courties, C.; Conan, Pascal; Oriol, L.; Sofen, L. E.; Moutin, T.; Van Mooy, B. A. S.. |
| Intact polar membrane lipids compose a significant fraction of cellular material in plankton and their synthesis imposes a substantial constraint on planktonic nutrient requirements. As a part of the Biogeochemistry from the Oligotrophic to the Ultraoligotrophic Mediterranean (BOUM) cruise we examined the distribution of several classes of intact polar diacylglycerolipids (IP-DAGs) across the Mediterranean, and found that phospholipid concentration as a percent of total lipids correlated with phosphate concentration. In addition, the ratios of non-phosphorus lipids to phospholipids - sulfoquinovosyldiacylglycerol (SQDG) to phosphatidylglycerol (PG), and betaine lipids to phosphatidylcholine (PC) - were also found to increase from west to east across the... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24405/22410.pdf |
| |
|
|
| Tanaka, T.; Thingstad, T. F.; Christaki, U.; Colombet, J.; Cornet-barthaux, V.; Courties, C.; Grattepanche, J. -d.; Lagaria, A.; Nedoma, J.; Oriol, L.; Psarra, S.; Pujo-pay, M.; Van Wambeke, France. |
| We investigated the identity of the limiting nutrient of the pelagic microbial food web in the Mediterranean Sea using nutrient manipulated microcosms during summer 2008. Experiments were carried out with surface waters at the center of anticyclonic eddies in the Western Basin, the Ionian Basin, and the Levantine Basin. In situ, the ratio of N to P was always higher in both dissolved and particulate organic fractions compared to the Redfield ratio, suggesting a relative P-starvation. In each experiment, four different treatments in triplicates (addition of ammonium, phosphate, a combination of both, and the unamended control) were employed and chemical and biological parameters monitored throughout a 3-4 day incubation. Temporal changes of turnover time of... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24395/22406.pdf |
| |
|
|
| Christaki, U.; Van Wambeke, France; Lefevre, D.; Lagaria, A.; Prieur, L.; Pujo-pay, M.; Grattepanche, J. -d.; Colombet, J.; Psarra, S.; Dolan, J. R.; Sime-ngando, T.; Conan, Pascal; Weinbauer, M. G.; Moutin, T.. |
| The abundance and activity of the major members of the heterotrophic microbial community - from viruses to ciliates - were studied along a longitudinal transect across the Mediterranean Sea in the summer of 2008. The Mediterranean Sea is characterized by a west to east gradient of deepening of DCM (deep chlorophyll maximum) and increasing oligotrophy reflected in gradients of biomass and production. However, within this well documented longitudinal trend, hydrological mesoscale features exist and likely influence microbial dynamics. Here we present data from a W-E transect of 17 stations during the period of summer stratification. Along the transect the production and fate of organic matter was investigated at three selected sites each one located in the... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24400/22422.pdf |
| |
|
|
|
