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This is a summary of the activities and results of JERICO-NEXT Work Package 3 Innovations in Technology and Methodology, Task 3.1 Automated platform for the observation of phytoplankton diversity in relation to ecosystem services. The aim is to provide an advanced report on the last developments dedicated to the observation of the phytoplankton diversity by applying novel techniques on automated platforms. The work was carried out in close connection with task 4.1 Biodiversity of plankton, harmful algal blooms and eutrophication. The partners involved in these developments are CNRS, SYKE, SMHI, HZG, RWS, VLIZ CEFAS and Ifremer. Subcontractors in WP4, task 4.1 are WHOI, Scanfjord AB, Tomas Rutten b.v., CytoBuoy b.v. and UGent - PAE. The work was carried out mainly in the field with activities in the Baltic Sea, the Kattegat-Skagerrak, the Celtic seas-English Channel-North Sea Area, the Western Mediterranean, as well as in shared studies with other WP3.4 and WP4.4 in the Bay of Biscay and, out of Europe, in the Benguela Current. Instrument platforms included continuous recording (Ferrybox or assimilated) systems on research vessels, on ships of opportunity, instrumented oceanographic buoys/fixed platforms and land-based systems. Common implementations were carried out in some observatories, allowing inter comparison of sensors and some techniques. In addition, work on developing and testing new algorithms have been carried out in offices and laboratories. Three international workshops have been successfully arranged, one in Wimereux, France (June 2016 – organised by CNRS-LOG), one in Gothenburg, Sweden (September 2016, organised by SMHI) and one in Marseille (March 2019 – organised by CNRS MIO) connected to a EuroMarine workshop. Partners presented, discussed, were able to inter compare the sensors and techniques to be implemented in the field (Goetborg) and were trained to different automated analytical procedures and tools (for automated flow cytometry, Marseille). The work was divided into three sections but there is substantial overlap and cooperation. One example is that reference samples analysed in the microscope were used for completing and/or evaluating the quality of some of the automated methods. Imaging in flow and in situ imaging of plankton (led by SMHI) The work included evaluating instruments and developing algorithms for automated identification of phytoplankton automated image acquisition (in flow or in situ). Three different commercial instruments and one instrument prototype were used. On the Swedish west coast (Skagerrak coast) a study of harmful algae and other phytoplankton was carried out near a mussel farm. The Imaging Flow Cytobot was deployed in situ and collected samples at six different depths for approximately two months. In the English Channel the old generation of FlowCAM and a prototype system, the FastCam, were used to analyse samples on research vessels or in the laborator. A colour version of FlowCAM was used both during a cruise in the Baltic Sea-Kattegat-Skattegat (July 2017) as well as in coastal monitoring in the Baltic and the Channel). In addition, the CytoSense and CytoSub were used to collect images in flow. The in situ video system UVP5 was implemented during a cruise in the Baltic Sea-Skagerrak-Kattegat area, together with a new generation of FlowCAM of faster acquisition and providing colour images and CytoSense. A major task was to develop and evaluate plankton identification algorithms. This included the use of a subset of images of organisms for training the software tools. Existing software were improved (as the PhytoZooImage) and an image data system/platform named EcoTaxa was described and is currently available for storing and cooperative analysis/discrimination of plankton images. Single-cell optical characterization (led by CEFAS) Automated flow cytometers (FCM, CytoSense/CytoSub, Cytobuoy b.v.) were implemented on a Ferry line, on research vessels and a fixed platform to investigate functional groups of phytoplankton. In the Western Mediterranean the main targets were the picoplankton and the nanoplankton while in the other areas pico-, nano- and microplankton were in focus. Several cruises were carried out in the Channel and North Sea to follow combined diatoms and Phaeocystis bloom development. A cruise covering the Baltic Sea and Skagerrak-Kattegat area had a main focus on cyanobacteria and dinoflagellates. Moreover, inter comparisons of machines and on clustering analysis methods were performed. Finally, a combination of FCM and multi-spectral fluorometer continuous recording was coupled with physical and hydrological continuous measurements in the southern Bay of Biscay. Bio-optical Instrumentation (led by SYKE) Novel multi-wavelength fluorometers for detecting phycoerythrin indicative e.g. of certain cyanobacteria and of cryptophytes were evaluated in the Baltic Sea. Multi wavelength fluorometers were also used in the Benguela current, during the Gothenburg workshop, as well as on a variety of field cruises from the southern Bay of Biscay to the E. Channel and North Sea, in order to discriminate amongst main phytoplankton pigmentary groups. The manufacturers’ algorithms were found to be partly inaccurate for detecting algal groups based on photosynthetic pigment composition. New dedicated fingerprints were used in field work to improve discrimination amongst phytoplankton groups. A principle component analyses approach was also evaluated. Single wavelength fluorometers were evaluated in several sea areas. Sun induced photoquenching had a strong effect on fluorescence yield. In the North Sea and the Norwegian Sea multi spectral absorption was used to detect chlorophyll and phytoplankton groups based on pigment content. Variable fluorometers were implemented on both samples, continuous recording and profiles in the E. Channel and North Sea, as well as in the Baltic and Skagerrak-Kattegat, for studying photosynthetic parameters and potential primary productivity. Recommendations are made on the strategy and type of measurements to carry out. Recent work (since mid 2017) in task 3.1 Some field work was continued, especially at the Utö observatory in the Baltic Sea. The new data collected was processed together with old data and used for improving the discrimination of phytoplankton taxa or functional groups by inter-comparison of techniques and continued algorithm development which are described in the present deliverable 3.2. Scientific publication of results is in progress. A special issue in the open access journal Diversity (MPI) is being discussed. Some results and strategy were presented during a symposium in Hannover, in October 2017 and during the FerryBox workshop on board the ship Colour Fantasy later in October 2017 and in FerryBox meetings in 2018 and 2019. Results were also presented during the third JERICO-NEXT workshop on automated plankton observation in Marseille in March 2018 and some analytical tools for flow cytometry were presented and further directions as well as connections with modelling and remote sensing were discussed during the EuroMarine meeting that followed. A special session was held during the International Conference on Harmful Algae (ICHA) in Nantes in October 2018, and more presentations were carried out in 2019 meetings (IMBER, OceanObs, etc.). Main conclusions 1. The methods used are reliable for automated observation of phytoplankton biodiversity (functional groups, size classes, taxa when possible) and biomass, complementing manual methods for sampling and microscope analyses. 2. Operating the equipment and interpreting the results still need a lot of knowledge and time. Even though some operational procedures can be established, the standardization of analytical and data processing as well as data management need more development. The degree of automation varies depending on the method considered. 3. Imaging in flow and in situ imaging provide means for identifying and counting phytoplankton at the genus or species level. Also, biomass based on cell volume of individual cells can be estimated. Development of classifiers for automated identification of organisms is time consuming and requires specific skills on signal analysis and on taxonomy. 4. Flow cytometry has proven to be a useful tool for counting phytoplankton and for describing the phytoplankton community as size-based classes and functional groups. There was an agreement to report the phytoplankton count in four groups for inter comparison purposes: Synechococcus (pico-cyanobacteria), pico-eukaryotic organisms, nanoplankton and microplankton. 5. Single and multi-wavelength fluorometry makes it possible to estimate phytoplankton biomass (at a chlorophyll-a basis) and to differentiate phytoplankton based on photosynthetic pigments. Sunlight induced photo-quenching is a problem for estimating chlorophyll a from fluorescence. For instruments mounted buoys or vessels, night time data can be used to minimize the problem. 6. Multi-wavelength absorption is a useful tool for estimating chlorophyll a and is also useful for discriminating between phytoplankton groups based on pigment content. 7. Variable (active) fluorescence is available for addressing phytoplankton physiology, photosynthetic parameters and we could estimate primary productivity on both continuous sub-surface recording and water column profiles, mediating careful coupling with other optical and also biogeochemical analysis.

This is a summary of the activities and results of JERICO-NEXT Work Package 3 Innovations in Technology and Methodology,Task 3.1 Automated platform for the observation of phytoplankton diversity in relation to ecosystem services. The aim is to provide an advanced report on the last developments dedicated to the observation of the phytoplankton diversity by applying novel techniques on automated platforms. The work was carried out in close connection with task 4.1 Biodiversity of plankton, harmful algal blooms and eutrophication.The partners involved in these developments are CNRS, SYKE, SMHI, HZG, RWS, VLIZ CEFAS and Ifremer. Subcontractors in WP4, task 4.1 are WHOI, Scanfjord AB, Tomas Rutten b.v., CytoBuoy b.v. and UGent -PAE.The work was carried out mainly in the field with activities in the Baltic Sea, the Kattegat-Skagerrak, the Celtic seas-English Channel-North Sea Area, the Western Mediterranean, as well as in shared studies with other WP3.4 and WP4.4 in the Bay of Biscay and, out of Europe, in the Benguela Current. Instrument platforms included continuous recording (Ferrybox or assimilated) systems on research vessels, on ships of opportunity, instrumented oceanographic buoys/fixed platforms and land-based systems. Common implementations were carried out in some observatories, allowing inter comparison of sensors and some techniques. In addition, work on developing and testing new algorithms have been carried out in offices and laboratories. Three international workshops have been successfully arranged, one in Wimereux, France (June 2016 –organised by CNRS-LOG), one in Gothenburg, Sweden (September 2016, organised by SMHI) and one in Marseille (March 2019–organised by CNRS MIO) connected to a EuroMarine workshop. Partners presented, discussed, were able to inter compare the sensors and techniques to be implemented in the field (Goetborg) and were trained to different automated analytical procedures and tools (for automated flow cytometry, Marseille).The work was divided into three sections but there is substantial overlap and cooperation. One example is that reference samples analysed in the microscope were used for completing and/or evaluating the quality of some of the automated methods.Imaging in flow and in situimaging of plankton (led by SMHI) The work included evaluating instruments and developing algorithms for automated identification of phytoplankton automated image acquisition (in flow or in situ). Three different commercial instruments and one instrument prototype were used. On the Swedish west coast (Skagerrakcoast) a study of harmful algae and other phytoplankton was carried out near a mussel farm. The Imaging Flow Cytobot was deployed in situ and collected samples at six different depths for approximately two months. In the English Channel the old generation of FlowCAM and a prototype system, the FastCam, were used to analyse samples on research vessels or in the laboratory. A colour version of FlowCAM was used both during a cruise in the Baltic Sea-Kattegat-Skattegat (July 2017) as well as in coastal monitoring in the Baltic and the Channel). In addition, the CytoSense and CytoSub were used to collect images in flow. The in situ video system UVP5 was implemented during a cruise in the Baltic Sea-Skagerrak-Kattegatarea, together with a new generation of FlowCAM of faster acquisition and providing colour images and CytoSense. A major task was to develop and evaluate plankton identification algorithms. This included the use of a subset of images of organisms for training the software tools. Existing software were improved (as the PhytoZooImage) and an image data system/platform named EcoTaxa was described and is currentlyavailable for storing and cooperative analysis/discrimination of plankton images.Single-cell optical characterization (led by CEFAS) Automated flow cytometers (FCM, CytoSense/CytoSub, Cytobuoy b.v.) were implemented on a Ferry line, on research vessels and a fixed platform to investigate functional groups of phytoplankton. In the Western Mediterranean the main targets were the picoplankton and the nanoplankton while in the other areas pico-, nano-and microplankton were in focus. Several cruises were carried out in the Channel and North Sea to follow combined diatoms and Phaeocystis bloom development. A cruise covering the Baltic Sea and Skagerrak-Kattegat area had a main focus on cyanobacteria and dinoflagellates. Moreover, inter comparisons of machines and on clustering analysis methods were performed. Finally, a combination of FCM and multi-spectral fluorometer continuous recording wascoupled with physical and hydrological continuous measurements in the southern Bay of Biscay. JERICO-NEXT Reference:JERICO-NEXT-WP3-D3.2-120819-V5 Page 5/88 Bio-optical Instrumentation (led by SYKE) Novel multi-wavelength fluorometers for detecting phycoerythrin indicative e.g. of certain cyanobacteria and of cryptophytes were evaluated in the Baltic Sea. Multi wavelength fluorometers were also used in the Benguela current, during the Gothenburg workshop, as well as on a variety of field cruises from the southern Bay of Biscay to the E. Channel and North Sea, in order to discriminate amongst main phytoplankton pigmentary groups. The manufacturers’ algorithms were found to be partly inaccurate for detecting algal groups based on photosynthetic pigment composition. New dedicated fingerprints were used in field work to improve discrimination amongst phytoplankton groups. A principle component analyses approach was also evaluated. Single wavelength fluorometers were evaluated in several sea areas. Sun induced photoquenching had a strong effect on fluorescence yield. In the North Sea and the Norwegian Sea multi spectral absorption was used to detect chlorophyll and phytoplankton groups based on pigment content.Variable fluorometers were implemented on both samples, continuous recording and profiles in the E. Channel and North Sea, as well as in the Baltic and Skagerrak-Kattegat, for studying photosynthetic parameters and potential primary productivity. Recommendations are made on the strategy and type of measurements to carry out. Recent work (since mid 2017) in task 3.1. Some field work was continued, especially at the Utö observatory in the Baltic Sea. The new data collected was processed together with old data and used for improving the discrimination of phytoplankton taxa or functional groups by inter-comparison of techniques and continued algorithm development which are described in the present deliverable 3.2.Scientific publication of results is in progress. A special issue in the open access journal Diversity (MPI) is being discussed. Some results and strategy were presented during a symposium in Hannover, in October 2017 and during the FerryBox workshop on board the ship Colour Fantasy later in October 2017and in FerryBox meetings in 2018 and 2019. Results were also presented during the third JERICO-NEXT workshopon automated plankton observationin Marseille in March 2018 some analytical tools for flow cytometry were presented and further directions as well as connections with modelling and remote sensing were discussed during the EuroMarine meeting that followed. A special session was held during the International Conference on Harmful Algae (ICHA) in Nantes in October 2018, and more presentations were carried out in 2019 meetings (IMBER, OceanObs, etc.). Main conclusions: 1.The methods used are reliable for automated observation of phytoplankton biodiversity (functional groups, size classes, taxa when possible) and biomass,complementing manual methods for sampling and microscope analyses. 2.Operating the equipment and interpreting the results still need a lot of knowledge and time. Even though some operational procedures can be established, the standardization of analytical and data processing as well as data management need more development. The degree of automation varies depending on the method considered. 3. Imaging in flow and in situ imaging provide means for identifying and counting phytoplankton at the genus or species level. Also, biomass based on cell volume of individual cells can be estimated. Development of classifiers for automated identification of organisms is time consuming and requires specific skills on signal analysis and on taxonomy. 4. Flow cytometry has proven to be a useful tool for counting phytoplankton and for describing the phytoplankton community as size-based classes and functional groups. There was an agreement to report the phytoplankton count in four groups for inter comparison purposes: Synechococcus(pico-cyanobacteria), pico-eukaryotic organisms, nanoplankton and microplankton. 5. Single and multi-wavelength fluorometry makes it possible to estimate phytoplankton biomass (at a chlorophyll-a basis) and to differentiate phytoplankton based on photosynthetic pigments. Sunlight induced photo-quenching is a problem for estimating chlorophyllafrom fluorescence. For instruments mounted buoys or vessels, night time data can be used to minimize the problem. 6. Multi-wavelength absorption is a useful tool for estimating chlorophyll a and is also useful for discriminating between phytoplankton groups based on pigment content. 7. Variable(active) fluorescence is available for addressing phytoplankton physiology, photosynthetic parameters and we could estimate primary productivity on both continuous sub-surface recording and water column profiles, mediating careful coupling with other optical and also biogeochemical analysis. Published Contributors: Hedy Aardema, Michael Brosnahan, Reinhoud de Blok, Pascal Claquin, Gérald Grégori, Florent Colas, Elisabeth Debusschere, Klaas Deneudt,Jacco Kromkamp, Soumaya Lahbib, Alain Lefebvre,Arnaud Louchart, Klas Möller, Emilie Poisson-Caillault, Thomas Rutten, Machteld Rijkeboer, Suvi Rytövuori,Lars Stemmann, Melilotus Thyssen, Lennert Tyberghein, Jochen Wollschläger and Pasi Ylöstalo. Current 14 Phytoplankton biomass and diversity TRL 8 Actual system completed and "mission qualified" through test and demonstration in an operational environment (ground or space) Best Practice Manual (incl. handbook, guide, cookbook etc)

International audience

The European Union Water Framework Directive (WFD) refers to phytoplankton as one of the biological quality elements that should be regularly monitored and evaluated thanks to three ecological indices: biomass, abundance and composition. The first two have already been defined, but the third one has not yet been proposed in the English Channel-Atlantic zone. The construction of a composition indice must consider the diversity of all the phytoplankton. As the microscopic counts concern only the micro-phytoplankton, it is necessary to use additional information which concerns the nano- and pico-phytoplankton, of great importance when estimating the phytoplankton diversity. These components of the phytoplankton can be measured by different complementary techniques: traditional or scanning flow cytometry, HPLC pigments analysis, spectral fluorescence, FlowCAM / PhytoImage, genetic biodiversity. In order to define the indicators for the WFD, while considering the phytoplankton dynamics in all the marine waters, it is necessary to use high resolution approaches, thanks to the development of new sensors and data analysis tools. The actions described in the present report concern the samples and continuous measurements ongoing since 2013, carried out in collaboration between the LOG laboratory (CNRS UMR 8187) from Wimereux and the laboratory IFREMER LER/Boulogne, including the participation of laboratories DYNECO/PELAGOS, DYNECO/VIGIES from IFREMER, and LISIC-ULCO from Calais. The aim was to continue the comparison of results obtained by different innovative techniques, as the flow cytometry and the spectral fluorescence, by applying these techniques to samples that come from networks or monitoring cruises ongoing in Eastern English Channel. These measurements were carried out referring to microscopic counts and pigments analysis (traditional methods used as reference for phytoplankton monitoring). These innovative techniques, when used at high resolution, permit a better understanding of the phytoplankton diversity and allow not only the construction of a composition indice for the WFD, but help bringing some important information, that could be used to estimate the ecological quality of all marine waters, in the frame of the Marine Strategy Framework Directive, L'élément de qualité phytoplancton doit être évalué dans le cadre de la Directive Cadre sur L’Eau grâce à trois indices : biomasse, abondance et composition. Les deux premiers indices, biomasse et abondance, ont déjà été définis. L’indice composition a quant à lui fait l'objet d'une proposition précise en Méditerranée, mais pas en Manche - Atlantique. Les travaux antérieurs montrent que la construction d'un indice de composition doit tenir compte de la diversité de l'ensemble du phytoplancton. Or, les comptages microscopiques ne concernent en général que le micro-phytoplancton. Il est donc nécessaire de prendre en compte des informations supplémentaires qui tiennent compte du nano- et du picophytoplancton, dont l'importance dans la diversité du phytoplancton est cruciale. Afin d'appréhender la diversité du phytoplancton dans toutes ses composantes, il est donc proposé de ne pas se limiter au microphytoplancton, mais de considérer également les autres composants du phytoplancton, tels que le nano- et le pico-phytoplancton. Ceux-ci peuvent être mesurés par différentes techniques, qui sont complémentaires : cytométrie en flux traditionnelle ou cytométrie en flux permettant d’enregistrer le profil optique de chaque particule, analyse des pigments par HPLC, fluorescence spectrale, FlowCAM / PhytoImage, biodiversité génétique. Par ailleurs, pour prendre en compte la dynamique du compartiment phytoplanctonique dans l’ensemble des eaux marines (en vue de définir les indicateurs pour la Directive Cadre Stratégie Milieu Marin (DCSMM), des mesures à haute résolution deviennent indispensables et possibles grâce au développement de nouveaux capteurs et systèmes d’analyse des résultats. Les différentes actions du présent livrable concernent les échantillonnages et mesures en cours depuis 2013, principalement réalisées en collaboration entre l’UMR LOG de Wimereux et le laboratoire IFREMER LER/Boulogne, en collaboration avec les laboratoires DYNECO/PELAGOS, DYNECO/VIGIES d’IFREMER et LISIC-ULCO. Tout particulièrement, il s’agissait de poursuivre la comparaison des résultats obtenus à partir de différentes techniques innovantes, dont la cytométrie en flux et la fluorimétrie spectrale, en appliquant ces techniques aux échantillons issus des réseaux ou des campagnes de surveillance et d’observation en cours en Manche orientale et Mer du Nord sud. Ces mesures ont été réalisées en référence aux données impliquant des comptages microscopiques et des analyses pigmentaires (méthodes traditionnelles pour le suivi du phytoplancton). Ces techniques, de par la possibilité de les utiliser à haute résolution, permettent de mieux appréhender la diversité du phytoplancton et devraient donc permettre non seulement de construire un indice de composition pour la DCE, mais également d'apporter des informations cruciales, qui pourraient être utilisées pour estimer le bon état écologique des eaux marines du point de vue du phytoplancton dans le cadre de la DCSMM.

L'utilisation des rapid light curves (RLC) et des steady state light curves (SSLC), pour la caractérisation in situ de l'activité photosynthétique du phytoplancton, à différentes échelles de temps, a été comparée. La possibilité d'utiliser les paramètres photosynthétiques des RLC pour prédire ceux de SSLC a été évaluée. Les résultats montrent que les RLC sont un bon outil pour la caractérisation de l'activité photosynthétique à différentes échelles temporelles

L'élément de qualité phytoplancton doit être évalué dans le cadre de la Directive Cadre sur L’Eau grâce à trois indices : biomasse, abondance et composition. Les deux premiers indices, biomasse et abondance, ont déjà été définis. L’indice composition a quant à lui fait l'objet d'une proposition précise en Méditerranée, mais pas en Manche - Atlantique. Les travaux antérieurs montrent que la construction d'un indice de composition doit tenir compte de la diversité de l'ensemble du phytoplancton. Or, les comptages microscopiques ne concernent en général que le micro-phytoplancton. Il est donc nécessaire de prendre en compte des informations supplémentaires qui tiennent compte du nano- et du picophytoplancton, dont l'importance dans la diversité du phytoplancton est cruciale. Afin d'appréhender la diversité du phytoplancton dans toutes ses composantes, il est donc proposé de ne pas se limiter au microphytoplancton, mais de considérer également les autres composants du phytoplancton, tels que le nano- et le pico-phytoplancton. Ceux-ci peuvent être mesurés par différentes techniques, qui sont complémentaires : cytométrie en flux traditionnelle ou cytométrie en flux permettant d’enregistrer le profil optique de chaque particule, analyse des pigments par HPLC, fluorescence spectrale, FlowCAM / PhytoImage, biodiversité génétique. Par ailleurs, pour prendre en compte la dynamique du compartiment phytoplanctonique dans l’ensemble des eaux marines (en vue de définir les indicateurs pour la Directive Cadre Stratégie Milieu Marin (DCSMM), des mesures à haute résolution deviennent indispensables et possibles grâce au développement de nouveaux capteurs et systèmes d’analyse des résultats. Les différentes actions du présent livrable ont été principalement réalisées en collaboration entre l’UMR LOG de Wimereux et le laboratoire IFREMER LER/Boulogne avec participation des laboratoires DYNECO/PELAGOS, DYNECO/VIGIES d’IFREMER, du LISIC-ULCO de Calais et les partenaires du projet DYMAPHY. Plus particulièrement, il s’agissait de comparer des résultats obtenus à partir de différentes techniques innovantes, dont la cytométrie en flux de type scanning et la fluorimétrie spectrale. Pour ce faire, l’analyse des premières comparaisons de mesures réalisées dans le cadre du projet INTERREG IVA « 2 Mers » DYMAPHY à la fois lors de campagnes communes et au niveau des sites d’observation et de surveillance en Manche Orientale seront présentées. Les données disponibles impliquant également, comme référence, des comptages microscopiques et des analyses pigmentaires seront également analysées en tant que référence (méthodes traditionnelles pour le suivi du phytoplancton). Le suivi combiné de la distribution spatiale phytoplanctonique à haute résolution (kilométrique ou sub-kilométrique) au cours de campagnes océanographiques internationales ou au cours de campagnes d’observation régulières réalisées à haute résolution temporelle (hebdomadaire et parfois journalière) a permis de mettre en évidence, par des techniques complémentaires aux comptages microscopiques, de la complexité des proliférations/accumulation, des changements de dominance d’un groupe phytoplanctonique à un autre, répondant à des changements des conditions du milieu et d’avancée de la saison. Les analyses pigmentaires ont permis de compléter les données de référence auxquelles les techniques semi-automatisées telles que la cytométrie en flux de type scanning (CytoSense) et la fluorimétrie spectrale ont pu être comparées. Ces techniques, de par la possibilité de les utiliser à haute résolution, permettent de mieux appréhender la diversité du phytoplancton et devraient donc permettre non seulement de construire un indice de composition pour la DCE, mais également d'apporter des informations cruciales, qui pourraient être utilisées pour estimer le bon état écologique des eaux marines du point de vue du phytoplancton dans le cadre de la DCSMM.