Nicolas MAYOT
Post-doctoral Researcher Scientist
Bigelow Laboratory for Ocean Sciences (website)
East Boothbay, ME 04544, USA

Education


2016, Ph.D. in Oceanography, Université Pierre et Marie Curie (Paris, France)

2013, M.Sc. in Oceanography and Marine Environment, Université Pierre et Marie Curie (Paris, France)

Options: remote sensing, ecosystem modelling, data analysis, planktonic ecosystem

2011, B.Sc. in Natural and Life Sciences (Nantes, France)

Options: biology and environment

Research interests


  • Understanding how physical-biological interactions influence the biological carbon pump in the ocean
  • Studying the primary production and organic carbon fluxes, from bloom events, annual cycles and interannual variability
  • Coupling data from ship observations, remote sensing, autonomous platforms, and models

Research and Professional Experiences


2017 – now > Post-doctoral research project, Bigelow, East Boothbay, USA

“Primary production changes across the Subarctic Atlantic: The physical and ecological roles of surface advection”

Grant from NASA: Ocean Biology and Biogeochemistry

Research Group: Air Sea Interactions Laboratory

Supervisor: Dr. Paty Matrai

2013 – 2016 > Ph.D. research project, UPMC & CNRS, Villefranche-sur-mer, France

“Phytoplankton phenology in the Mediterranean Sea”

Grant from ERC remOcean, and a regional doctoral scholarship

Research Group: Remote Sensing and Optics Applied to Marine Biogeochemistry

Supervisors: Dr. Fabrizio D’Ortenzio & Dr. Hervé Claustre

2013 > Master’s Thesis, UPMC, Villefranche-sur-mer, France

“Spatial distribution of zooplankton and particulate matter in the oceans”

Research Group: Processes in Pelagic Ecosystems

Supervisors: Dr. Lars Stemmann & Dr. Lionel Guidi

Peer-Reviewed Publications


In press / In Revision / Submitted

Testor, P., A. Bosse, L. Houpert, F. Margirier, L. Mortier, H. Le Goff, D. Dausse, M. Labaste, J. Karstensen, D. Hayes, A. Olita, E. Heslop, F. D’Ortenzio, N. Mayot, H. Lavigne, O. Pasqueron de Fommervault, L. Coppola, L. Prieur, V. Taillandier, X. Durrieu de Madron, F. Bourrin, G. Many, P. Damien, C. Estournel, P. Marsaleix, I. Taupier-Letage, P. Raimbault, R. Waldman, M-N. Bouin, H. Giordani, G. Caniaux, S. Somot, V. Ducrocq and P. Conan, Dense water formations in the North Western Mediterranean: from the physical forcings to the biogeochemical consequences, In press, Journal of Geophysical Research: Oceans

Taillandier, V., T. Wagener, F. D’Ortenzio, N. Mayot, H. Legoff, J. Ras, L. Coppola, O. Pasqueron de Fommervault1, C. Schmechtig, E. Diamond, H. Bittig, D. Lefevre, E. Leymarie, A. Poteau and L. Prieur, DHydrography in the Mediterranean Sea during a cruise with RV Tethys 2 in May 2015, Submitted to Earth System Science Data

2017

Mayot, N., F. D’Ortenzio, J. Uitz, B. Gentili, D. Antoine and H. Claustre (2017), Influence of the phytoplankton community structure on the spring and annual primary production in the North-Western Mediterranean Sea, Journal of Geophysical Research: Oceans | PDF

Abstract

Satellite ocean color observations revealed that unusually deep convection events in 1999, 2005, 2006, 2010 and 2013 led to an increased phytoplankton biomass during the spring bloom over a large area of the North-Western Mediterranean Sea (NWM). Here we investigate the effects of these events on the seasonal phytoplankton community structure, we quantify their influence on primary production, and we discuss the potential biogeochemical impact. For this purpose, we compiled in situ phytoplankton pigment data from five ship surveys performed in the NWM and from monthly cruises at a fixed station in the Ligurian Sea. We derived primary production rates from a light-photosynthesis model applied to these in situ data. Our results confirm that the maximum phytoplankton biomass during the spring bloom is larger in years associated with intense deep convection events (+ 51%). During these enhanced spring blooms, the contribution of diatoms to total phytoplankton biomass increased (+ 33 %), as well as the primary production rate (+ 115 %). The occurrence of a highly productive bloom is also related to an increase in the phytoplankton bloom area (+ 155 %), and in the relative contribution of diatoms to primary production (+ 63 %). Therefore, assuming that deep convection in the NWM could be significantly weakened by future climate changes, substantial decreases in the spring production of organic carbon and of its export to deep waters can be expected.

Mayot, N., F. D’Ortenzio, V. Taillandier, L. Prieur, O. Pasqueron de Fommervault, H. Claustre, A. Bosse, P. Testor and P. Conan (2017), Physical and biogeochemical controls of the phytoplankton blooms in North Western Mediterranean Sea: a multiplatform approach over a complete annual cycle (2012-2013 DEWEX experiment), Journal of Geophysical Research: Oceans | PDF

Abstract

The North Western Mediterranean Sea exhibits recurrent and significant autumnal and spring phytoplankton blooms. The existence of these two blooms coincide with typical temperate dynamics. To determine the potential control of physical and biogeochemical factors on these phytoplankton blooms, data from a multiplatform approach (combining ships, Argo and BGC-Argo floats, and bio-optical gliders) were analyzed in association with satellite observations in 2012-2013. The satellite framework allowed a simultaneous analysis over the whole annual cycle of in situ observations of mixed layer depth, photosynthetical available radiation, particle backscattering, nutrients (nitrate and silicate) and chlorophyll-a concentrations. During the year 2012-2013, satellite ocean color observations, confirmed by in situ data, have revealed the existence of two areas (or bioregions) with comparable autumnal blooms but contrasting spring blooms. In both bioregions, the ratio of the euphotic zone (defined as the isolume 0.415 mol photons m-2 d-1, Z0.415) and the MLD identified the initiation of the autumnal bloom, as well as the maximal annual increase in [Chl-a] in spring. In fact, the autumnal phytoplankton bloom might be initiated by mixing of the summer shallowing deep chlorophyll maximum, while the spring restratification (when Z0.415/MLD ratio became > 1) might induce surface phytoplankton production that largely overcomes the losses. Finally, winter deep convection events that took place in one of the bioregions induced higher net accumulation rate of phytoplankton in spring associated with a diatom-dominated phytoplankton community principally. We suggest that very deep winter MLD lead to an increase in surface silicates availability, which favored the development of diatoms.

Bosse, A., P. Testor, N. Mayot, L. Prieur, F. D’Ortenzio, L. Mortier, H. Le Goff, C. Gourcuff, L. Coppola, H. Lavigne and P. Raimbault, A submesoscale coherent vortex in the Ligurian Sea: from dynamical barriers to biological implications, In revision, Journal of Geophysical Research: Oceans, 122(8), 6196–6217 | PDF

Séverin, T., F. Kessouri, M. Rembauville, E. Sanchéz-Pérez, L. Oriol, J. Caparros, M. Pujo-Pay, J-F. Ghiglione, F. D’Ortenzio, V. Taillendier, C. Ulses, C. Estournel, N. Mayot and P. Conan (2017), Open-ocean convection process: a driver of the winter nutrient supply and the spring phytoplankton distribution in the Northwestern Mediterranean Sea, Journal of Geophysical Research: Oceans, 122(6), 4587–4601 | PDF

Ayata, S-D., J-O. Irisson, A. Aubert, L. Berline, J-C. Dutay, N. Mayot, A-E. Nieblas, F. D’Ortenzio, J. Palmieri, G. Reygondeau, V. Rossi, and C. Guieu, Regionalisation of the Mediterranean basin, a MERMEX synthesis, Progress in Oceanography | PDF

2016

Biard, T., L. Stemmann, M. Picheral, N Mayot, P. Vandromme, H. Hauss, G. Gorsky, L. Guidi, R. Kiko and F. Not (2016). In situ observations unveil an unexpectedly large biomass of Radiolaria and Phaeodaria (Rhizaria) in the oceans, Nature, 532, 504-507 | PDF on ResearchGate

Abstract

Planktonic organisms play crucial roles in oceanic food webs and global biogeochemical cycles. Most of our knowledge about the ecological impact of large zooplankton stems from research on abundant and robust crustaceans, and in particular copepods. A number of the other organisms that comprise planktonic communities are fragile, and therefore hard to sample and quantify, meaning that their abundances and effects on oceanic ecosystems are poorly understood. Here, using data from a worldwide in situ imaging survey of plankton larger than 600 µm, we show that a substantial part of the biomass of this size fraction consists of giant protists belonging to the Rhizaria, a super-group of mostly fragile unicellular marine organisms that includes the taxa Phaeodaria and Radiolaria (for example, orders Collodaria and Acantharia). Globally, we estimate that rhizarians in the top 200 m of world oceans represent a standing stock of 0.089 Pg carbon, equivalent to 5.2% of the total oceanic biota carbon reservoir. In the vast oligotrophic intertropical open oceans, rhizarian biomass is estimated to be equivalent to that of all other mesozooplankton (plankton in the size range 0.2–20 mm). The photosymbiotic association of many rhizarians with microalgae may be an important factor in explaining their distribution. The previously overlooked importance of these giant protists across the widest ecosystem on the planet changes our understanding of marine planktonic ecosystems.

Mayot, N., F. D’Ortenzio, M. Ribera d’Alcalà, H. Lavigne, and H. Claustre (2016), Interannual variability of the Mediterranean trophic regimes from ocean color satellites, Biogeosciences, 13, 1901–1917 | PDF

Abstract

D’Ortenzio and Ribera d’Alcalà (2009, DR09 hereafter) divided the Mediterranean Sea into “bioregions” based on the climatological seasonality (phenology) of phytoplankton. Here we investigate the interannual variability of this bioregionalization. Using 16 years of available ocean color observations (i.e. SeaWiFS and MODIS), we analyzed the spatial distribution of the DR09 trophic regimes on an annual basis. Additionally, we identified new trophic regimes, exhibiting seasonal cycles of phytoplankton biomass different from the DR09 climatological description and named “Anomalous”. Overall, the classification of the Mediterranean phytoplankton phenology proposed by DR09 (i.e. “No Bloom”, “Intermittently”, “Bloom” and “Coastal”), is confirmed to be representative of most of the Mediterranean phytoplankton phenologies. The mean spatial distribution of these trophic regimes (i.e. bioregions) over the 16 years studied is also similar to the one proposed by DR09, although some annual variations were observed at regional scale. Discrepancies with the DR09 study were related to interannual variability in the sub-basin forcing: winter deep convection events, frontal instabilities, inflow of Atlantic or Black Sea Waters and river run-off. The large assortment of phytoplankton phenologies identified in the Mediterranean Sea is thus verified at the interannual scale, further supporting the “sentinel” role of this basin for detecting the impact of climate changes on the pelagic environment.

Conference Presentations


Oral Presentations

Mayot, N., F. D’Ortenzio, V. Taillandier, O. Pasqueron, L. Prieur, P. Testor, A. Bosse, P. Conan, H. Claustre. Influence of the deep convection on the phytoplankton spring bloom, Argo-France User Meeting 2016, Toulon, June 2016

Abstract

En Méditerranée Nord-Occidental, le mélange hivernal de la colonne d’eau est suivi d’une efflorescence printanière du phytoplancton en surface. Certaines années ce mélange hivernal est associé à des évènements de convections profondes qui engendrent une efflorescence phytoplanctonique particulièrement importante. Pour étudier cette influence positive de la convection profonde sur le développement phytoplanctonique, une année d’observations à l’échelle du bassin Nord-Occidental de paramètres physiques et biogéochimiques provenant de plusieurs plateformes a été utilisée (5 campagnes océanographiques – 249 stations, 10 mission gliders – 2113 profils, 13 Argo – 493 profils et 5 BioArgo – 292 profils). Cela a nécessité dans un premier temps une intercalibration de l’ensemble des capteurs des plateformes autonomes. Par la suite, ces observations in-situ, dont la représentation spatiale et/ou temporelle est restreinte, ont été combinées avec des images satellites (mesurant la concentration en chlorophylle-a, estimateur de la biomasse phytoplanctonique) afin qu’elles soient interprétées et intégrées dans un contexte spatiotemporel plus large et cohérent. L’effet de la convection profonde sur l’établissement d’efflorescences printanières plus importantes a été avéré. Celles-ci sont provoquées par une communauté phytoplanctonique printanière principalement composée de diatomées. Car la convection profonde, en engendrant la remontée en surface d’eaux profondes présentant des concentrations élevées en silicates, pourrait influer sur la composition de la communauté phytoplanctonique. Cette étude a été rendue possible grâce à une intégration pertinente des plateformes autonomes à l’analyse, par l’utilisation d’images satellites, permettant d’étudier les périodes non couvertes par des campagnes océanographiques.

Mayot, N., F. D’Ortenzio, J. Uitz and H. Claustre. Phytoplankton traits over an annual cycle in the NW Mediterranean. OSM 2016, New-Orleans, USA, February 2016 | PDF

Abstract

In spring 2013, an intense phytoplankton bloom was observed in North Western Mediterranean (NWM) from ocean color images and in situ data (ships, profiling floats and gliders). The bloom was spatially structured in two distinct regions (or bioregions), where the seasonal evolutions of the mixed layer and of the chlorophyll-a concentrations follow two different dynamics. In the bioregion associated to the center of the NWM (hereafter named CB), the winter mixed layer and the spring bloom were more intense (respectively 2350m and 4.8 mg m-3) than for the bioregion located at the periphery (PB, respectively 300m and 2.3 mg m-3). Higher proportion of diatoms (and lower proportion of nano-flagellates) in CB than in PB are observed. Therefore, the intense bloom in the CB region was a diatom bloom, while the less intense bloom in PB was dominated by nano-flagellates. We hypothesized that the observed differences in phytoplankton spring communities between both bioregions are essentially explained by a difference in the silicate availability, a consequence of the contrasting winter mixing intensities.

Mayot, N., F. D’Ortenzio, V. Taillandier, O. Pasqueron, L. Prieur, P. Testor, A. Bosse, P. Conan, F. Kessouri, C. Estournel, H. Claustre. Phytoplankton bloom in the NW Mediterranean: impacts of a deep convection event revealed by Bio-Argo, Bio-Gliders and Ship data. GAIC2015 – Sustained ocean observing for the next decade, Galway, Ireland, September 2015

Abstract

The North Western Mediterranean Sea (NWM) combines, in a relatively small area, recurrent intense open-ocean deep convection events and significant phytoplankton spring blooms (in terms of spatial extent and of observed chlorophyll-a concentrations). However, the importance of the deep convection in structuration of spring blooms is still debated. To answer to the still open questions, an intense scientific effort coupling ship observations and autonomous platforms has been carried out in the NWM during the winter-to-spring transition 2012-2013 (DEWEX program).

Mayot, N., F. D’Ortenzio, M. Ribera d’Alcalà, H. Lavigne, and H. Claustre. Mediterranean phytoplankton phenology: Interannual variability of phytoplankton biomass and physical-biological interactions from Bio-Argo floats and satellite. GIS-COOC 2015 Workshop, Bordeaux, February 2015

Poster Presentations

Barbieux, M., C., Scheurle, Mathieu Ardyna, T., Harmel, M., Ferraris, T., Jessin, L., Lacour, N., Mayot , E., Organelli, O., Pasqueron De Fommervault, C., Penkerc’h, A., Poteau, J., Uitz, S., Ramondec, R., Sauzède, V., Vellucci and H., Claustre. Building an early career network through outreach projects: The “mon océan & moi” example. OSM 2016, New-Orleans, USA, February 2016

Abstract

The ocean plays an important role in the global processes of our planet, from climate change to sea level rise, uptake of carbon dioxide to fisheries stocks. In addition, its scientific importance, extraordinary beauty and public fascination provide perfect ingredients for both education and public outreach. Four years ago, after the launch of the “mon océan & moi” outreach project, an early career network (Ph.D. students and postdocs) has been formed to “promote collaborations/exchanges between the scientific and educational worlds in order to co-elaborate a teaching method for raising the awareness of school children on marine environments”. Scientists are pursuing new research yielding improved knowledge and new documentation resources. However, they lack the communication skills to make the subject accessible to the general public. On the other hand, teachers must be informed of recent discoveries and of new resources for educational purposes. To fill this gap, the early career scientists developed, in collaboration with a school authority and an experienced science communicators team, both a trail education program tested directly in middle and high schools and innovative supporting material (i.e., animations, educative video clips and experiments, interactive maps and quizzes). Here we outline a set of guidelines as to how to improve science outreach across a variety of disciplines (e.g., science, technology, engineering) and how this may impact the experience of early career scientists. These tips will be useful for other early career scientists and science outreach projects, large or small, regional, national or international. Such novel outreach initiatives will help educate current and next generations about the importance of ocean environments and the relevance of ocean sciences for the society, and may serve as an example of teamwork for other young scientists.

Mayot, N., V., Taillandier, L., Prieur, O., Pasqueron de Fommervault, G., Obolensky, A., Poteau, A., Bosse, P., Testor, P., Conan, F., D’Ortenzio. Combining Bio-Argo Floats with other observing platforms to evaluate the physical- biogeochemical interactions in the North Western Mediterranean Sea. 5th Euro-Argo User Workshop, Brest, France, March 2015 | PDF

Abstract

During the winter-to-spring transition of 2012-2013, three Bio-Argo floats (PROVOR CTS4 nke, NAOS [Novel Argo Ocean observing System] project) equipped with biogeochemical sensors (chlorophyll-a, nitrate, backscattering, irradiance, dissolved oxygen) have been deployed in the North Western Mediterranean Sea (NWM). In this area, a large observation activity has been carried out, including, others than Bio-Argo floats, also Bio-Gliders (MOOSE [Mediterranean Ocean Observing System for the Environment] project) and research cruises (DEWEX [DEep Water formation Experiment] project).
The NWM is the most productive area of the Mediterranean basin, characterized by a temperate seas dynamic, with a strong oligotrophy in summer and a phytoplankton bloom in spring. Its hydrology is influenced by large winter convection events, with recurrent observations of deep water formation. This specific hydrology is supposed to impact the phytoplankton phenology, by modifying the amplitude and/or phasing of environmental conditions. The combined use of Bio-Argo with other autonomous platforms (Bio-Gliders, satellite) and “classical” sampling (cruises) allowed for an unprecedented description of the main physical forcings and of the phytoplankton response in the area.

Teaching, Outreach and Communication Activities


2017 > Communication manager at the Villefranche Oceanographic Laboratory (Villefranche-sur-mer, France)

Including social media management, for outreach projects and the Biogeochemical-Argo program

2013 – 2016 > Scientific mediator for school classes, preparation of the materials: courses and presentations,

At the regional level (Alpes-Maritimes, France), for the projects:

  • Adopt a Float: “The project is based on the adoption by a class of an autonomous profiling float. The children follow it, which allows them to participate in the observations collected by this float and the sciences associated.”
  • MEDITES: “The project favors collaboration between the scientific and educational worlds to provide an access to scientific culture for the youth, to awaken their curiosity and critical thinking, and also to promote and enhance the diversity.”

2014 & 2015 > Co-organizer of the event “Young Researchers’ Day” (Villefranche-sur-mer, France)

2013 & 2015 > Preparation of talks, suitable for 7 to 77 years old, for the French Science Festival

Skills and Activities


Scientific Cruise:

Bio-Argo-Med cruise (NAOS project), R/V Thetis II, Mediterranean Sea – May 2015 (1 month) Scientific Cruise:

> Recovery and deployment of profiling floats (2 Argo floats, 8 BGC-Argo floats)

> Responsible for the calibration of oxygen optodes on BGC-Argo float

> Collection of seawater samples for the measurements of nutrient concentration

> Collection and filtration of seawater samples for phytoplankton pigment determination

Computer skills:

> Data analysis softwares – MATLAB, R

> Operating Systems – Windows, Linux

> Applications – Microsoft Office, LibreOffice, Creative Suite Adobe

Languages:

> French – mother tongue

> English – spoken, read and written