title: Nature of phosphorus limitation in the ultraoligotrophic eastern Mediterranean.
abstract: Phosphate addition to surface waters of the ultraoligotrophic, phosphorus-starved eastern Mediterranean in a Lagrangian experiment caused unexpected ecosystem responses. The system exhibited a decline in chlorophyll and an increase in bacterial production and copepod egg abundance. Although nitrogen and phosphorus colimitation hindered phytoplankton growth, phosphorous may have been transferred through the microbial food web to copepods via two, not mutually exclusive, pathways: (i) bypass of the phytoplankton compartment by phosphorus uptake in heterotrophic bacteria and (ii) tunnelling, whereby phosphate luxury consumption rapidly shifts the stoichiometric composition of copepod prey. Copepods may thus be coupled to lower trophic levels through interactions not usually considered.
authors.affiliation: Department of Biology, University of Bergen, Bergen, Norway. frede.thingstad@bio.uib.no
authors.forename: T F
authors.initials: TF
authors.lastname: Thingstad
authors.forename: M D
authors.initials: MD
authors.lastname: Krom
authors.forename: R F C
authors.initials: RF
authors.lastname: Mantoura
authors.forename: G A F
authors.initials: GA
authors.lastname: Flaten
authors.forename: S
authors.initials: S
authors.lastname: Groom
authors.forename: B
authors.initials: B
authors.lastname: Herut
authors.forename: N
authors.initials: N
authors.lastname: Kress
authors.forename: C S
authors.initials: CS
authors.lastname: Law
authors.forename: A
authors.initials: A
authors.lastname: Pasternak
authors.forename: P
authors.initials: P
authors.lastname: Pitta
authors.forename: S
authors.initials: S
authors.lastname: Psarra
authors.forename: F
authors.initials: F
authors.lastname: Rassoulzadegan
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Tselepides
authors.forename: P
authors.initials: P
authors.lastname: Wassmann
authors.forename: E M S
authors.initials: EM
authors.lastname: Woodward
authors.forename: C Wexels
authors.initials: CW
authors.lastname: Riser
authors.forename: G
authors.initials: G
authors.lastname: Zodiatis
authors.forename: T
authors.initials: T
authors.lastname: Zohary
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism; D018533:Biomass; D002244:Carbon / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D016798:Ciliophora / Q000254:growth & development / Q000378:metabolism; D033342:Copepoda / Q000378:metabolism / Q000502:physiology*; D004058:Diffusion; D017753:Ecosystem; D020387:Food Chain; D008522:Mediterranean Sea; D009566:Nitrates / Q000032:analysis / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis; D009586:Nitrogen Fixation; D010710:Phosphates / Q000032:analysis / Q000378:metabolism*; D010758:Phosphorus / Q000032:analysis; D010839:Phytoplankton / Q000254:growth & development*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012621:Seasons; D046940:Synechococcus / Q000378:metabolism; D015048:Zooplankton / Q000254:growth & development / Q000378:metabolism
chemical_list: D009566:Nitrates; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D002734:Chlorophyll; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen