Global Distribution of Microbial Abundance and Biomass in Subseafloor Sediment

Authors

Jens Kallmeyer
Robert Pockalny, University of Rhode IslandFollow
Rishi Ram Adhikari
David C. Smith, University of Rhode IslandFollow
Steven D'Hondt, University of Rhode IslandFollow

Document Type

Article

Date of Original Version

10-2-2012

Department

Oceanography

Abstract

The global geographic distribution of subseafloor sedimentary microbes and the cause(s) of that distribution are largely unexplored. Here, we show that total microbial cell abundance in subseafloor sediment varies between sites by ca. five orders of magnitude. This variation is strongly correlated with mean sedimentation rate and distance from land. Based on these correlations, we estimate global subseafloor sedimentary microbial abundance to be 2.9⋅10²⁹ cells [corresponding to 4.1 petagram (Pg) C and ∼0.6% of Earth’s total living biomass]. This estimate of subseafloor sedimentary microbial abundance is roughly equal to previous estimates of total microbial abundance in seawater and total microbial abundance in soil. It is much lower than previous estimates of subseafloor sedimentary microbial abundance. In consequence, we estimate Earth’s total number of microbes and total living biomass to be, respectively, 50–78% and 10–45% lower than previous estimates.

Citation/Publisher Attribution

Jens Kallmeyer, Robert Pockalny, Rishi Ram Adhikari, David C. Smith, and Steven D’Hondt. (2012). "Global distribution of microbial abundance and biomass in subseafloor sediment." Proceedings of the National Academy of Sciences, 109(40), 16213-16216.

Available at: https://doi.org/10.1073/pnas.1203849109

Publisher Statement

Freely available online through the PNAS open access option. © 2012 by The National Academy of Sciences of the USA