title: Both respiration and photosynthesis determine the scaling of plankton metabolism in the oligotrophic ocean.
abstract: Despite its importance to ocean-climate interactions, the metabolic state of the oligotrophic ocean has remained controversial for >15 years. Positions in the debate are that it is either hetero- or autotrophic, which suggests either substantial unaccounted for organic matter inputs, or that all available photosynthesis (P) estimations (including (14)C) are biased. Here we show the existence of systematic differences in the metabolic state of the North (heterotrophic) and South (autotrophic) Atlantic oligotrophic gyres, resulting from differences in both P and respiration (R). The oligotrophic ocean is neither auto- nor heterotrophic, but functionally diverse. Our results show that the scaling of plankton metabolism by generalized P:R relationships that has sustained the debate is biased, and indicate that the variability of R, and not only of P, needs to be considered in regional estimations of the ocean's metabolic state.
authors.affiliation: Departamento de Ecología y Biología animal, Universidad de Vigo, E36310 Vigo, Spain.|Estación de Ciencias Marinas de Toralla, Universidad de Vigo, Toralla island, E-36331 Vigo, Spain.
authors.forename: Pablo
authors.identifier: http://orcid.org/0000-0001-6087-6272
authors.initials: P
authors.lastname: Serret
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Carol
authors.initials: C
authors.lastname: Robinson
authors.affiliation: Departamento de Ecología y Biología animal, Universidad de Vigo, E36310 Vigo, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Aranguren-Gassis
authors.affiliation: Departamento de Ecología y Biología animal, Universidad de Vigo, E36310 Vigo, Spain.
authors.forename: Enma Elena
authors.initials: EE
authors.lastname: García-Martín
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: Niki
authors.initials: N
authors.lastname: Gist
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: Vassilis
authors.initials: V
authors.lastname: Kitidis
authors.affiliation: Departamento de Ecología y Biología animal, Universidad de Vigo, E36310 Vigo, Spain.|Estación de Ciencias Marinas de Toralla, Universidad de Vigo, Toralla island, E-36331 Vigo, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Lozano
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: John
authors.initials: J
authors.lastname: Stephens
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Harris
authors.affiliation: British Oceanographic Data Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK.
authors.forename: Rob
authors.initials: R
authors.lastname: Thomas
mesh_terms: D001267:Atlantic Ocean; D052818:Autotrophic Processes; D019069:Cell Respiration; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D052836:Heterotrophic Processes; D010788:Photosynthesis; D010933:Plankton / Q000378:metabolism*
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A