Long-term monitoring of the phytoplankton at the SOMLIT-Astan Station in the Western English Channel from 2000 to present

The monitoring at the SOMLIT-Astan station (north of Roscoff - France, Western English Channel) was designed to study long term changes in phytoplankton communities in a global change context (diversity, phenology). Phytoplankton communities are monitored twice a month according to the SOMLIT monitoring program (Service d'Observation en Milieu Littoral : http://somlit.epoc.u-bordeaux1.fr/fr/), national network performing measurements of hydrological parameters. SOMLIT-Astan phytoplankton monitoring contains :1/ Microphytoplankton - Species abundances (according to Utermöhl method microphytoplankton abundances - number of cells per liter) ; 2/ Microphytoplankton - Species semi-quantitative occurrences (20µm net haul, occurrence code : "1" present, "2" numerous, "3"dominant) ; 3/ Fonctionnal groups abundances (Flowcytometry - number of cells per milliliter) : pico-, nano-phytoplankton, heterotrophic and autotrophic bacteria.