The effects of nutrient additions on particulate and dissolved primary production and metabolic state in surface waters of three Mediterranean eddies
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Non |
| Statut de publication | : | Publié |
| Année de publication | : | 2011 |
| Auteurs (9) | : | LAGARIA A PSARRA S LEFÈVRE Dominique VAN WAMBEKE France COURTIES C PUJO-PAY Mireille ORIOL L TANAKA Tsuneo CHRISTAKI Urania |
| Revue scientifique | : | Biogeosciences |
| Volume | : | 8 |
| Fascicule | : | 9 |
| Pages | : | 2595-2607 |
| DOI | : | 10.5194/bg-8-2595-2011 |
| URL | : | <go to isi>://wos:000295375700014 |
| Abstract | : | 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 photosynthate (PER) displayed the lowest values (4-8%) in the +NP treatment. Among the three treatments (+N, +P, +NP), the +NP had the strongest effect on oxygen metabolic rates, leading to positive values of net community production (NCP>0). These changes of NCP were mainly due to enhanced gross primary production (GPP) rather than reduced dark community respiration rates (DCR). In all three sites, in +NP treatment autotrophic production (whether expressed as GPP or PP(total)) was sufficient to fulfil the estimated carbon requirements of heterotrophic prokaryotes, while addition of nitrogen alone (+N) had a weaker effect on GPP, resulting in metabolically balanced systems. At the three sites, in treatments with N (+N, +NP), phytoplankton and heterotrophic prokaryote production were positively correlated. Heterotrophic conditions were observed in the Control and +P treatment at the central and eastern sites, and autotrophic production was not sufficient to supply estimated bacterial carbon demand, evidence of a decoupling of phytoplankton production and consumption by heterotrophic prokaryotes. |
| Mots-clés | : | almeria-oran front net community production microbial food webs organic-matter heterotrophic bacteria p-limitation phosphorus limitation microcosm experiment plankton metabolism carbon flux Environmental Sciences & Ecology Geology |
| Commentaire | : | ISI Document Delivery No.: 826SU Times Cited: 7 Cited Reference Count: 70 Lagaria, A. Psarra, S. Lefevre, D. Van Wambeke, F. Courties, C. Pujo-Pay, M. Oriol, L. Tanaka, T. Christaki, U. Tanaka, Tsuneo/G-3751-2011; Pujo-Pay, Mireille/E-9547-2011 SESAME IP project; BOUM experiment This work is a contribution to the BOUM (Biogeochemistry from the Oligotrophic to the Ultraoligotrophic Mediterranean) experiment of the French national LEFE-CYBER program, the European IP SESAME project and the international IMBER project. It was supported by a Ph.D. grant of SESAME IP project for A. Lagaria and by the BOUM experiment. We are grateful to the coordinators of SESAME E. Papathanassiou and of BOUM T. Moutin for their support. We wish to thank the captain and crew of the R/V Atalante for their assistance during the cruise, A. Fernandez for her valuable help with the on board experimental work and R. Mauriac for laboratory assistance with counting of 14C samples. We are also grateful to J. Dolan for very useful discussions on our data and critical reading of the manuscript and to the anonymous reviewers for constructive comments. 7 Copernicus gesellschaft mbh Gottingen Ecology; Geosciences, Multidisciplinary |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Lagaria A, Psarra S, Lefèvre D, Van Wambeke F, Courties C, Pujo-Pay M, Oriol L, Tanaka T, Christaki U (2011) The effects of nutrient additions on particulate and dissolved primary production and metabolic state in surface waters of three Mediterranean eddies. Biogeosciences 8: 2595-2607 | doi: 10.5194/bg-8-2595-2011
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