title: Re-examination of the relationship between marine virus and microbial cell abundances.
abstract: Marine viruses are critical drivers of ocean biogeochemistry, and their abundances vary spatiotemporally in the global oceans, with upper estimates exceeding 10(8) per ml. Over many years, a consensus has emerged that virus abundances are typically tenfold higher than microbial cell abundances. However, the true explanatory power of a linear relationship and its robustness across diverse ocean environments is unclear. Here, we compile 5,671 microbial cell and virus abundance estimates from 25 distinct marine surveys and find substantial variation in the virus-to-microbial cell ratio, in which a 10:1 model has either limited or no explanatory power. Instead, virus abundances are better described as nonlinear, power-law functions of microbial cell abundances. The fitted scaling exponents are typically less than 1, implying that the virus-to-microbial cell ratio decreases with microbial cell density, rather than remaining fixed. The observed scaling also implies that viral effect sizes derived from 'representative' abundances require substantial refinement to be extrapolated to regional or global scales.
authors: School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors: Charles H
authors: CH
authors: Wigington
authors: Department of Mathematics and Statistics, Northern Arizona University, Flagstaff, Arizona 86011, USA.
authors: Derek
authors: D
authors: Sonderegger
authors: Department of Biological Oceanography, Royal Netherlands Institute for Sea Research (NIOZ), 1790 AB Den Burg, Texel, The Netherlands.|Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1090 GE, Amsterdam, The Netherlands.
authors: Corina P D
authors: CP
authors: Brussaard
authors: Department of Microbiology, The University of Tennessee, Knoxville, Tennessee 37996, USA.
authors: Alison
authors: A
authors: Buchan
authors: Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors: Jan F
authors: JF
authors: Finke
authors: Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors: Jed A
authors: http://orcid.org/0000-0002-2361-1985
authors: JA
authors: Fuhrman
authors: Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
authors: Jay T
authors: JT
authors: Lennon
authors: Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000, Helsingør, Denmark.
authors: Mathias
authors: M
authors: Middelboe
authors: Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.|Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.|Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.|Program in Integrated Microbial Diversity, Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors: Curtis A
authors: http://orcid.org/0000-0002-0372-0033
authors: CA
authors: Suttle
authors: Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey 08540, USA.
authors: Charles
authors: C
authors: Stock
authors: Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.
authors: William H
authors: WH
authors: Wilson
authors: Plant and Soil Sciences, Delaware Biotechnology Institute, Delaware Technology Park, Newark, Delaware 19711, USA.
authors: K Eric
authors: KE
authors: Wommack
authors: Department of Microbiology, The University of Tennessee, Knoxville, Tennessee 37996, USA.
authors: Steven W
authors: SW
authors: Wilhelm
authors: School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.|School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors: Joshua S
authors: http://orcid.org/0000-0002-3433-8312
authors: JS
authors: Weitz
mesh_terms: D059001:Aquatic Organisms / Q000254:growth & development*; D009792:Oceans and Seas; D011156:Population Density; D012623:Seawater / Q000382:microbiology* / Q000821:virology*; D062211:Spatio-Temporal Analysis; D014780:Viruses / Q000254:growth & development*