High contribution of Rhizaria (Radiolaria) to vertical export in the California Current Ecosystem revealed by DNA metabarcoding

TitleHigh contribution of Rhizaria (Radiolaria) to vertical export in the California Current Ecosystem revealed by DNA metabarcoding
Publication TypeJournal Article
Year of Publication2019
AuthorsGutierrez-Rodriguez A., Stukel M.R, Santos A.L dos, Biard T., Scharek R., Vaulot D., Landry MR, Not F.
JournalIsme Journal
Volume13
Pagination964-976
Date Published2019/04
Type of ArticleArticle
ISBN Number1751-7362
Accession NumberWOS:000461719600009
Keywordscarbon export; Distribution; Environmental Sciences & Ecology; living radiolarians; Marine snow; microbiology; oceanic; phaeodarian radiolarians; picoeukaryotic diversity; sinking particle-flux; surface; twilight zone; waters; zooplankton fecal pellets
Abstract

Passive sinking of particulate organic matter (POM) is the main mechanism through which the biological pump transports surface primary production to the ocean interior. However, the contribution and variability of different biological sources to vertical export is not fully understood. Here, we use DNA metabarcoding of the 18S rRNA gene and particle interceptor traps (PITs) to characterize the taxonomic composition of particles sinking out of the photic layer in the California Current Ecosystem (CCE), a productive system with high export potential. The PITs included formalin-fixed and 'live' traps to investigate eukaryotic communities involved in the export and remineralization of sinking particles. Sequences affiliated with Radiolaria dominated the eukaryotic assemblage in fixed traps (90%), with Dinophyta and Metazoa making minor contributions. The prominence of Radiolaria decreased drastically in live traps, possibly due to selective consumption by copepods, heterotrophic nanoflagellates, and phaeodarians that were heavily enriched in these traps. These patterns were consistent across the water masses surveyed extending from the coast to offshore, despite major differences in productivity and trophic structure of the epipelagic plankton community. Our findings identify Radiolaria as major actors in export fluxes in the CCE.

DOI10.1038/s41396-018-0322-7
Student Publication: 
No