Lack of P-limitation of phytoplankton and heterotrophic prokaryotes in surface waters of three anticyclonic eddies in the stratified Mediterranean Sea
| Type | Article | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Date | 2011 | ||||||||
| Language | English | ||||||||
| Author(s) | Tanaka T.1, Thingstad T. F.2, Christaki U.3, Colombet J.4, Cornet-Barthaux V.1, Courties C.5, 6, Grattepanche J. -D.3, Lagaria A.3, 7, Nedoma J.8, Oriol L.9, 10, Psarra S.7, Pujo-Pay M.9, 10, Van Wambeke France11 | ||||||||
| Affiliation(s) | 1 : Univ Aix Marseille 2, Lab Oceanog Phys & Biogeochim, Ctr Oceanol Marseille, CNRS,OSU,UMR 6535, F-13288 Marseille 09, France. 2 : Univ Bergen, Dept Biol, N-5006 Bergen, Norway. 3 : Univ Lille , CNRS, ULCO, LOG,UMR 8187, F-62930 Wimereux, France. 4 : Univ Clermont Ferrand, Lab Microorganismes Genome & Environm, F-63177 Aubiere, France. 5 : Univ Paris 06, Observ Oceanol, UMS 2348, F-66651 Banyuls Sur Mer, France. 6 : CNRS, Observ Oceanol, UMS 2348, F-66651 Banyuls Sur Mer, France. 7 : Hellen Ctr Marine Res, Iraklion 71003, Crete, Greece. 8 : Inst Hydrobiol, Biol Ctr ASCR, Vvi, Ceske Budejovice 37005, Czech Republic. 9 : Univ Paris 06, Observ Oceanol, Lab Oceanog Microbienne, UMR 7621, F-66651 Banyuls Sur Mer, France. 10 : CNRS, Observ Oceanol, Lab Oceanog Microbienne, UMR 7621, F-66651 Banyuls Sur Mer, France. 11 : Univ Aix Marseille 2, Lab Microbiol Geochim & Ecol Marines, Ctr Oceanol Marseille, CNRS,OSU,UMR 6117, F-13288 Marseille, France. |
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| Source | Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2011 , Vol. 8 , N. 2 , P. 525-538 | ||||||||
| DOI | 10.5194/bg-8-525-2011 | ||||||||
| WOS© Times Cited | 77 | ||||||||
| Abstract | 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 phosphate and ATP, and alkaline phosphatase activity during the incubation suggested that the phytoplankton and heterotrophic prokaryotes (Hprok) communities were not P-limited at the sites. Furthermore, statistical comparison among treatments at the end of the incubation did not support a hypothesis of P-limitation at the three study sites. In contrast, primary production was consistently limited by N, and Hprok growth was not limited by N nor P in the Western Basin, but N-limited in the Ionian Basin, and N and P co-limited in the Levantine Basin. Our results demonstrated the gap between biogeochemical features (an apparent P-starved status) and biological responses (no apparent P-limitation). We question the general notion that Mediterranean surface waters are limited by P alone during the stratified period. | ||||||||
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