title: Marine mixotrophy increases trophic transfer efficiency, mean organism size, and vertical carbon flux.
abstract: Mixotrophic plankton, which combine the uptake of inorganic resources and the ingestion of living prey, are ubiquitous in marine ecosystems, but their integrated biogeochemical impacts remain unclear. We address this issue by removing the strict distinction between phytoplankton and zooplankton from a global model of the marine plankton food web. This simplification allows the emergence of a realistic trophic network with increased fidelity to empirical estimates of plankton community structure and elemental stoichiometry, relative to a system in which autotrophy and heterotrophy are mutually exclusive. Mixotrophy enhances the transfer of biomass to larger sizes classes further up the food chain, leading to an approximately threefold increase in global mean organism size and an ∼35% increase in sinking carbon flux.
authors.affiliation: School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, United Kingdom; Laboratoire des Sciences de l'Environnement Marin, Institut Universitaire Européen de la Mer, Technopole Brest Iroise, 29280 Plouzané, France; b.a.ward@bristol.ac.uk.
authors.forename: Ben A
authors.initials: BA
authors.lastname: Ward
authors.affiliation: Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Follows
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology; D052818:Autotrophic Processes / Q000502:physiology*; D018533:Biomass; D049628:Body Size; D057486:Carbon Cycle; D002734:Chlorophyll / Q000032:analysis / Q000528:radiation effects; D000077194:Chlorophyll A; D017753:Ecosystem; D005247:Feeding Behavior; D020387:Food Chain; D019015:Geologic Sediments; D052836:Heterotrophic Processes / Q000502:physiology*; D007501:Iron / Q000378:metabolism; D008954:Models, Biological; D058458:Nitrogen Cycle; D009792:Oceans and Seas; D010758:Phosphorus / Q000378:metabolism; D010788:Photosynthesis; D010933:Plankton / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D011235:Predatory Behavior; D012621:Seasons; D013472:Sunlight
chemical_list: D002734:Chlorophyll; D010758:Phosphorus; D007501:Iron; D000077194:Chlorophyll A
keywords: biological pump; mixotrophy; plankton; size; trophic transfer
references.citation: Sci Data. 2014 Dec 09;1:140048
references.pmid: 25977799
references.citation: Nature. 2008 Sep 11;455(7210):224-6
references.pmid: 18690208
references.citation: Ecol Lett. 2013 Mar;16(3):371-9
references.pmid: 23279624
references.citation: Proc Natl Acad Sci U S A. 2012 Apr 10;109(15):5756-60
references.pmid: 22451938
references.citation: Am Nat. 2011 Jul;178(1):98-112
references.pmid: 21670581