DOI: 10.17882/110112
title: Marine planktonic microorganisms abundances and optical properties obtained by flow cytometry for 2 long term time-series stations located off Roscoff (France, Western English Channel) : the offshore SOMLIT-Astan station (2000-2009) and the near-shore SOMLIT-Estacade station (2008-2012)

description: Long-term observation of the environment and ecosystems is essential to understand their evolution in the context of climate change.
To characterize the Western English Channel coastal ecosystems, the Station Biologique de Roscoff (France) has implemented various long term monitoring programs and projects, and takes part to several national networks. For example, hydrological parameters are monitored off Roscoff in the frame of the SOMLIT SNO – National Observation Service (https://www.somlit.fr/). This monitoring is operated for 2 stations with samples collected twice a month since 2000: the SOMLIT-Astan offshore station (http://marineregions.org/mrgid/5372), 2 nautical miles off Roscoff characterised by a permanently mixed water column (60 m. depth), and the SOMLIT-Estacade near-shore station (http://marineregions.org/mrgid/5371) close to the harbour influenced by coastal waters (3-11 m depth). The contextual hydrological parameters that can be accessed from the SOMLIT SNO (https://doi.org/10.17882/96634) are essential for studies conducted at local scales but also for comparative studies.
Monitoring of marine planktonic unicellular prokaryotic and eukaryotic communities is carried out along with the hydrological parameters since 2000 at the SOMLIT-Astan offshore station and since 2008 at the SOMLIT-Estacade station. The taxonomic diversity and wide size range (less than 1 µm to more than 200 µm) of planktonic unicellular eukaryotes and prokaryotes require specific analytical techniques. The flow cytometry technique is applied to the picoplanktonic (&lt; 3 µm) and nanoplanktonic (3 µm to 20 µm) fractions of these communities. Flow cytometry allows the discrimination of functional groups, based on their pigment types, sizes and light diffusion capacity: autotrophic eukaryotes and prokaryotes (cyanobacteria) and heterotrophic bacteria, thanks to induced fluorescence (fluorochrome).
Flow cytometry data (abundances and optical properties) related to these fonctionnal groups are provided in open access along with hydrological parameters for samples collected since 2010 and 2013 for respectively the SOMLIT-Astan and the SOMLIT-Estacade stations since these parameters have been integrated in the SOMLIT SNO (https://doi.org/10.17882/96634 ).
The following data relate to flow cytometry monitoring of pico- and nano-planktonic communities carried out from 2000 to 2009 at the SOMLIT-Astan offshore station and from 2008 to 2012 at the SOMLIT-Estacade coastal station. Datasets were extracted from the PELAGOS V2 database (https://pelagos.sb-roscoff.fr) resulting from collaborative work of the French marine stations involved in planktonic biodiversity monitoring. The database is now operated through the CDS-STAMAR data and services centre, part of the French national Ocean Data Cluster - ODATIS (https://www.odatis-ocean.fr/), in close collaboration with the ILICO Research Infrastructure (https://www.ir-ilico.fr/). Its contents is available to members of the PELAGOS community who signed a charter that defines data usage and redistribution terms.
In order to enhance the FAIRness level of the provided files, raw PELAGOS data extractions have been transformed :
 - original column headers have been made more readable,
 - new standardized columns have been added : station coordinates and Marine Region ID, depth classes, BODC/SeaDataNet terms for sampling instruments),
 - some less relevant columns have been removed : original cytogram file names, cytogram software version amongst others.
In the frame of the ILICO Research Infrastructure, additional time series are also performed by the Station Biologique de Roscoff:
- SNO COAST-HF, high frequency hydrological monitoring national network: https://coast-hf.fr/;
- SNO PHYTOBS-Network, microphytoplankton communities monitoring national network at SOMLIT-Astan station: https://www.phytobs.fr/ and data are available: https://doi.org/10.17882/85178
- SNO BENTHOBS, macrozoobenthos communities monitoring national network: https://www.benthobs.fr/.