The south equatorial Pacific is characterized by High Nutrient Low Chlorophyll regions, a feature essentially due to trace metals limitations. Within this area, a clear phytoplankton bloom is regularly observed downstream of the Marquesas Islands. This natural phenomenon creates an ideal situation to investigate open ocean ecosystems response to environmental perturbation. A fine scale mapping of the oceanographic context along with metagenomics and metatranscriptomics analysis of sampled planktonic communities was conducted during the Tara Oceans expedition. Four sampling locations were analysed in order to characterize the main phases of the bloom. Based on metatranscriptomic data from a large range of organism sizes, the first ever marine eukaryote reference gene catalogue including 9 millions of non-redundant sequences was established. This gene set was functionally and taxonomically described and the genomic and transcriptomic abundances of the genes were calculated. A shift in population composition and metabolic function (ions response, reproduction activity, energetic pathways ...) was associated with the bloom appearance. Our integrated dynamical view of a marine ecosystem response to a perturbation contribute greatly to our basic knowledge on phytoplankton bloom development.



Kirilovsky, A., ENS IBENS, France, kirilovs@biologie.ens.fr

Pelletier, E., CEA - Genoscope, France

Caputi, L., Stazione Zoologica Anton Dohrn, Italy

Paz-Yepes, J., ENS IBENS, France

Boccara, M., ENS IBENS, France

Aury, J. M., CEA - Genoscope, France

Bowler, C., ENS IBENS, France

Wincker, P., CEA - Genoscope, France

Not, F., Station Biologique de Roscoff, France

Iudicone, D., Stazione Zoologica Anton Dohrn, Italy


Oral presentation

Session #:075
Date: 2/26/2015
Time: 11:00
Location: Andalucia 1 (Floor 1)

Presentation is given by student: No