Seasonal Dynamics of Pico- and Nanoplankton in the NW Iberian Upwelling System: a Metabarcoding Approach

VI Simposio Internacional de Ciencias del Mar - VI International Symposium of Marine Sciences (ISMS 2018), 20- 22 June 2018, Vigo.-- 1 page

The diversity and variability of the small size fraction of the marine eukaryotic microbial plankton community was studied through the use of high throughput sequencing (HTS) in the NW Iberian upwelling system. The use of molecular tools enabled to identify and characterise the pico-(0.2-2 μm) and nanoplankton (2-20μm)components in that region, which remains underexplored owing to the difficulty of traditional methods such as microscopy to resolve the taxonomic structure of the smallest sized plankton. To this end, 8 seawater samples were taken from March to November 2012 in the Ría de Vigo. For each sample, between 1 -1.5 L of seawater was filtered sequentially through 20, 2 and 0.2 μm. From the 0.2 and 2 μm filters, DNA was extracted and the V4 region of the 18S rDNA genes was amplified by PCR and analyzed by Illumina sequencing. On each sampling day, data on hydrography, nutrients and microplankton were also taken, which allowedus to determine accompanying environmental conditions. The most abundant OTUs corresponded to organisms belonging to the following classes: Chlorophyta, Dinophyta, Ciliophora, Picozoaand Cryptophyta. The differential distribution of the organisms identified and the absence of some groups in some months suggesta remarkable seasonal distribution. The metabarcoding approach through HTS is a valuable tool to study pico-and nanoplankton, allowing their identification and determination of temporal variability. This kind of knowledge allows a better understanding of the biological communities and their ecology in this coastal upwelling region, providing key information on the lower trophic levels necessary for predicting how the system could react to future climate changes

This work was funded by DISTRAL (CTM2011-25035) and i-SMALL (CTM2014-56119-R) projects by the Spanish government. IGT was supported by a Post-doc grant by the Portuguese Foundation for Science and Technology (SFRH/BPD/108485/2015) Seasonal dynamics of pico-and nanoplankton in the NW Iberian upwelling system: a metabarcoding approach

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