Important contribution of macroalgae to oceanic carbon sequestration
Type
ArticleAuthors
Ortega, Alejandra
Geraldi, Nathan

Alam, Intikhab

Kamau, Allan

Acinas, Silvia G.
Logares, Ramiro

Gasol, Josep M.

Massana, Ramon

Krause-Jensen, Dorte

Duarte, Carlos M.

KAUST Department
Bioscience ProgramRed Sea Research Center (RSRC)
Computational Bioscience Research Center (CBRC)
Biological and Environmental Sciences and Engineering (BESE) Division
Marine Science Program
KAUST Grant Number
BAS/1/1071-01-01Date
2019-08-05Online Publication Date
2019-08-05Print Publication Date
2019-09Embargo End Date
2020-02-05Permanent link to this record
http://hdl.handle.net/10754/656768
Metadata
Show full item recordAbstract
The role of macroalgae in Blue Carbon assessments has been controversial, partially due to uncertainties about the fate of exported macroalgae. Available evidence suggests that macroalgae are exported to reach the open ocean and the deep sea. Nevertheless, this evidence lacks systematic assessment. Here, we provide robust evidence of macroalgal export beyond coastal habitats. We used metagenomes and metabarcodes from the global expeditions Tara Oceans and Malaspina 2010 Circumnavigation. We discovered macroalgae worldwide at up to 5,000 km from coastal areas. We found 24 orders, most of which belong to the phylum Rhodophyta. The diversity of macroalgae was similar across oceanic regions, although the assemblage composition differed. The South Atlantic Ocean presented the highest macroalgal diversity, whereas the Red Sea was the least diverse region. The abundance of macroalgae sequences attenuated exponentially with depth at a rate of 37.3% km−1, and only 24% of macroalgae available at the surface were expected to reach the seafloor at a depth of 4,000 m. Our findings indicate that macroalgae are exported across the open and the deep ocean, suggesting that macroalgae may be an important source of allochthonous carbon, and their contribution should be considered in Blue Carbon assessments.Citation
Ortega, A., Geraldi, N. R., Alam, I., Kamau, A. A., Acinas, S. G., Logares, R., … Duarte, C. M. (2019). Important contribution of macroalgae to oceanic carbon sequestration. Nature Geoscience, 12(9), 748–754. doi:10.1038/s41561-019-0421-8Sponsors
We thank the Tara Oceans Consortium for data availability. This research was supported by the Malaspina 2010 expedition, funded by the Spanish Ministry of Economy and Competitiveness through the Consolider-Ingenio programme to C.M.D. (reference: CSD2008-00077); CARMA, funded by the Independent Research Fund Denmark to D.K.-J. (reference: 8021-00222B); and King Abdullah University of Science and Technology’s project BAS/1/1071-01-01 to C.M.D. We thank all of the scientists and crew for support during sample collection on the Malaspina 2010 cruise, and especially E. Borrull, C. Díez-Vives, E. Lara, D. Vaqué, G. Salazar and F. Cornejo-Castillo for DNA sampling. The authors are grateful to the KAUST Supercomputing Laboratory (KSL) for the resources provided.Publisher
Springer Science and Business Media LLCJournal
Nature GeoscienceAdditional Links
http://www.nature.com/articles/s41561-019-0421-8https://digital.csic.es/bitstream/10261/192545/3/Ortega_et_al_2019_preprint.pdf
ae974a485f413a2113503eed53cd6c53
10.1038/s41561-019-0421-8