Seagrass sediments as a global carbon sink: Isotopic constraints

Hilary Kennedy*, Jeff Beggins, Carlos M. Duarte, James W. Fourqurean, Marianne Holmer, Núria Marbá, Jack J. Middelburg

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

306 Scopus citations

Abstract

Seagrass meadows are highly productive habitats found along many of the world's coastline, providing important services that support the overall functioning of the coastal zone. The organic carbon that accumulates in seagrass meadows is derived not only from seagrass production but from the trapping of other particles, as the seagrass canopies facilitate sedimentation and reduce resuspension. Here we provide a comprehensive synthesis of the available data to obtain a better understanding of the relative contribution of seagrass and other possible sources of organic matter that accumulate in the sediments of seagrass meadows. The data set includes 219 paired analyses of the carbon isotopic composition of seagrass leaves and sediments from 207 seagrass sites at 88 locations worldwide. Using a three source mixing model and literature values for putative sources, we calculate that the average proportional contribution of seagrass to the surface sediment organic carbon pool is ∼50%. When using the best available estimates of carbon burial rates in seagrass meadows, our data indicate that between 41 and 66 gC m-2 yr-1 originates from seagrass production. Using our global average for allochthonous carbon trapped in seagrass sediments together with a recent estimate of global average net community production, we estimate that carbon burial in seagrass meadows is between 48 and 112 Tg yr-1, showing that seagrass meadows are natural hot spots for carbon sequestration.

Original languageEnglish (US)
Article numberGB4026
JournalGlobal Biogeochemical Cycles
Volume24
Issue number4
DOIs
StatePublished - Dec 20 2010

ASJC Scopus subject areas

  • Global and Planetary Change
  • Environmental Chemistry
  • Environmental Science(all)
  • Atmospheric Science

Fingerprint Dive into the research topics of 'Seagrass sediments as a global carbon sink: Isotopic constraints'. Together they form a unique fingerprint.

Cite this