Seagrass ecosystems as a globally significant carbon stock

Authors

James W. Fourqurean, Department of Biological Sciences and Southeast Environmental Research Center, Florida International UniversityFollow
Carlos M. Duarte, Department of Global Change Research. IMEDEA (CSIC-UIB) Institut Mediterrani d’Estudis Avançats and The UWA Oceans Institute, University of Western AustraliaFollow
Hilary Kennedy, School of Ocean Sciences, College of Natural Sciences, Bangor UniversityFollow
Núria Marbà, Department of Global Change Research. IMEDEA (CSIC-UIB) Institut Mediterrani d’Estudis AvançatsFollow
Marianne Holmer, Institute of Biology, University of Southern DenmarkFollow
Miguel Angel Mateo, Centre for Advanced Studies of Blanes, (CEAB-CSIC)Follow
Eugenia T. Apostolaki, Institute of Oceanography, Hellenic Centre for Marine Research
Gary A. Kendrick, The UWA Oceans Institute and School of Plant Biology, University of Western AustraliaFollow
Dorte Krause-Jensen, Department of Bioscience, Aarhus UniversityFollow
Karen J. McGlathery, Department of Environmental Sciences, University of Virginia
Oscar Serrano, Centre for Advanced Studies of Blanes, (CEAB-CSIC)Follow

Abstract

The protection of organic carbon stored in forests is considered as an important method for mitigating climate change. Like terrestrial ecosystems, coastal ecosystems store large amounts of carbon, and there are initiatives to protect these ‘blue carbon’ stores. Organic carbon stocks in tidal salt marshes and mangroves have been estimated, but uncertainties in the stores of seagrass meadows—some of the most productive ecosystems on Earth—hinder the application of marine carbon conservation schemes. Here, we compile published and unpublished measurements of the organic carbon content of living seagrass biomass and underlying soils in 946 distinct seagrass meadows across the globe. Using only data from sites for which full inventories exist, we estimate that, globally, seagrass ecosystems could store as much as 19.9 Pg organic carbon; according to a more conservative approach, in which we incorporate more data from surface soils and depth-dependent declines in soil carbon stocks, we estimate that the seagrass carbon pool lies between 4.2 and 8.4 Pg carbon. We estimate that present rates of seagrass loss could result in the release of up to 299 Tg carbon per year, assuming that all of the organic carbon in seagrass biomass and the top metre of soils is remineralized.

Comments

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Fourqurean, J.W., C.M. Duarte, H. Kennedy, N. Marba, M. Holmer, M.A. Mateo, E.T. Apostolaki, G.A. Kendrick, D. Krause-Jensen, K.J. McGlathery, O. Serrano. 2012. Seagrass ecosystems as a globally significant carbon stock. Nature Geoscience DOI: 10.1038/NGEO1477