15 novembre 2014
After Portimão, the schooner Tara makes a stopover in Peniche, the 15th of November 2014.
15 th November at 2:30 pm : Talk by Noan le Bescot, scientist aboard Tara, at the Marine school of Peniche.
Tara will also meet the David Meilgueiro association, first intention at building a Portugese scientific sailing boat.
Tara Oceans: A sampling strategy for the study of marine plankton at global scale in their environmental context, the exemple of Dinoflagellates.
The Tara Oceans Expedition (2009-2013) was unique in that it sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies.
We will take the exemple of Dinoflagellates, a complex group of protists with a variety of morphologies, physiologies, and life cycles that gives them a strong capacity to adapt to all aquatic environments (marine and freshwater) and habitats (pelagic and benthic) while making it difficult to study their diversity and ecology. We used a massive rDNA metabarcodes dataset — ±2 millions rDNA sequences for each of 106 size-fractionated plankton communities — sampled during the Tara-Oceans expeditions (2009-2012). We show that dinoflagellate are the most diverse of all protistan lineages in the world plankton, and we unveil general patterns of biodiversity and abundance that are stable but differential across different plankton size-fractions, from the smallest and largely novel dinoflagellates in the piconano-plankton to the poorly known diversity of dinoflagellates living in symbiosis with mesoplankton organisms. Our analyses show the power of metabarcoding for semi-quantitative biodiversity assessment of entire compartments of the world plankton ecosystem that still escape microscopy investigations, and illustrate its promises to model the functional dynamics of pelagic biodiversity.