%0 Journal Article
%T The effects of nutrient additions on particulate and dissolved primary production and metabolic state in surface waters of three Mediterranean eddies
%+ Institut méditerranéen d'océanologie (MIO)
%+ Observatoire océanologique de Banyuls (OOB)
%+ Laboratoire d'Océanographie Microbienne (LOMIC)
%+ Laboratoire d'Océanographie Physique et Biogéochimique (LOPB)
%+ Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG)
%A Lagaria, A.
%A Psarra, S.
%A Lefèvre, Dominique
%A van Wambeke, France
%A Courties, C.
%A Pujo-Pay, Mireille
%A Oriol, L.
%A Tanaka, T.
%A Christaki, Urania
%Z The publication of this article is financed by CNRS-INSU
%< avec comité de lecture
%Z MIO:11-040
%@ 1726-4170
%J Biogeosciences
%I European Geosciences Union
%V 8
%P 2595-2607
%8 2011
%D 2011
%R 10.5194/bg-8-2595-2011
%K ALMERIA-ORAN FRONT
%K NET COMMUNITY PRODUCTION
%K MICROBIAL FOOD WEBS
%K ORGANIC-MATTER
%K HETEROTROPHIC BACTERIA
%K P-LIMITATION
%K PHOSPHORUS LIMITATION
%K MICROCOSM EXPERIMENT
%K PLANKTON METABOLISM
%K CARBON FLUX
%Z Sciences of the Universe [physics]/Ocean, AtmosphereJournal articles
%X We examined the effects of nutrient additions on rates of C-14-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 PPtotal) 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.
%G English
%2 https://hal.science/hal-00687934/document
%2 https://hal.science/hal-00687934/file/bg-8-2595-2011.pdf
%L hal-00687934
%U https://hal.science/hal-00687934
%~ IRD
%~ INSU
%~ UPMC
%~ UNIV-TLN
%~ CNRS
%~ UNIV-AMU
%~ UNIV-LITTORAL
%~ MIO
%~ OSU-INSTITUT-PYTHEAS
%~ GIP-BE
%~ LOPB
%~ LOMIC
%~ AGROPOLIS
%~ UPMC_POLE_3
%~ UNIV-LILLE
%~ SORBONNE-UNIVERSITE
%~ SU-INF-2018
%~ SU-SCIENCES
%~ UMS-2348
%~ MIO-CYBELE
%~ SU-TI
%~ LOG
%~ ALLIANCE-SU