Outputs

Abstract: The CABESTAN project addresses major knowledge gaps on the processes and drivers regulating carbon fluxes in coastal wetlands, from back-barrier marshes to intertidal areas. It focuses on how carbon capture, recycling, and storage respond to environmental gradients shaped by tidal cycles, salinity, eutrophication, substrate productivity, and climatic forcing along the Atlantic–Channel coastline.

Through a comparative multi-site study of nine locations between the Arcachon Basin and the Canche estuary, CABESTAN will generate new insights into the future of carbon sequestration in coastal wetlands under global climate change. Nearly 30 researchers from nine laboratories, spanning expertise in geochemistry, sedimentology, ecology, physiology, carbon flux measurement, organic matter analysis, remote sensing, and modeling, will collaborate within this multidisciplinary consortium.

Personnal note: My contribution to CABESTAN will focus on sampling and analyses conducted in the Brittany coastal zone, covering key aspects of carbon dynamics in intertidal areas and salt marshes.

Abstract: Intertidal sedimentary ecosystems, spanning over 10,000 km² along European coastlines, play a pivotal role in climate regulation, biodiversity support, and the provision of ecosystem services to coastal communities. Yet, these fragile habitats are increasingly fragmented and degraded due to human pressures and climate change. The REWRITE project brings together an interdisciplinary consortium of partners from 11 European countries, the UK, and North America to develop innovative strategies for their restoration and sustainable management. 

Over a five-year period (2023–2028), REWRITE will integrate ecological, biogeochemical, technological, and socio-economic approaches across 10 demonstration sites to assess and enhance the capacity of intertidal ecosystems to sequester carbon, buffer climate impacts, and sustain biodiversity. 

By engaging local stakeholders through Multi-Actor Labs and co-designing future scenarios, the project aims to generate scalable solutions for restoring land-sea interface habitats and ensuring resilient and sustainable European coastlines. 

Personnal note: My contribution to REWRITE will focus on mesocosm experiments and field measurements, all centered on the photosynthetic microphytobenthic compartment.

Abstract: Benthic pennate raphid diatoms exhibit directed motility, which has been crucial for their evolutionary success, diversification, and productivity. Despite decades of interest, significant knowledge gaps persist, and this project aims to address them through innovative methodological approaches: (i) a unique combination of microfluidics and microscopic imaging of photosynthetic activity to study photobehavior and photosynthesis of isolated cells in light microgradients; (ii) the use of a high-throughput chlorophyll fluorescence imaging method enabling rapid and integrated quantification of photosynthetic and migration responses in multiple samples.

The project results will contribute to an integrated understanding of the adaptive value of phototaxis in diatoms, elucidating how it enhances photosynthesis at the cellular level and supports high productivity in estuarine intertidal areas.

Personnal note: Currently, I have contributed to the publication of two papers associated with this project (P1-P2).

Abstract: The FEREE project aimed to evaluate the ecological balance of different sites with contrasting lateral hydraulic connectivities. The underlying hypothesis was that the ecological functioning of associated environments differs due to the gradients of expressed constraints (e.g., hydraulic management, frequency and duration of flooding, degree of salinity), leading to modifications in several processes associated with estuarine wetlands, such as: biomass production, filtration processes (soil-water interface), sediment dynamics, species selection by environmental filters, community arrangement (composition, diversity, etc.), trophic interactions, organic matter mineralization, and denitrification. 

Personal note: My main role was to assess the impact of water level management on the quality of organic matter and nitrogen cycle-related processes, as well as their connections. This task of the project was coordinated by Dr. Anniet Laverman. Currently, I have contributed to the publication of four papers associated with this part (P1-P4).

Abstract: The SPORES project focuses on nutrient cycles and primary production in the Seine Estuary. Its objective was to compile knowledge on biogeochemical processes related to organic matter dynamics, bacterial activity, and primary production in the water column, intertidal, and wetland areas, all essential to estuarine trophic networks. This work was organized around three main points: (1) Watershed inputs to the Seine Estuary, (2) Biogeochemical cycles and primary production dynamics in the Seine Estuary, and (3) Contributions of the estuary to the Seine Bay. 

This project serves as a diagnostic assessment of biogeochemical functions conducted for the REPERE project (Diagnosis and guidelines for the restoration of ecological functionality in the Seine). 

Personnal note: This project has offered me a great opportunity to interact with local stakeholders on the restoration priorities of an urbanized area, while expanding my knowledge on all biogeochemical cycles, allowing me to acquire a comprehensive view on urbanized ecosystem functioning. 

Abstract: The PHARESEE project convened a diverse array of scientific teams to investigate the ecological dynamics of the northern mudflat within the Seine estuary. The overarching goal was to elucidate the intricate ecological interplay among hydro-sedimentary, biological, and biogeochemical processes governing this habitat. Novel data highlighted the pivotal role of microphytobenthos in estuarine trophic networks, with meiobenthic and macrobenthic organisms predominantly reliant on these microalgae for sustenance. Research endeavors also examined the influence of macrobenthic species, particularly Hediste diversicolor and Scrobicularia plana, on mudflat stability, revealing nuanced effects under varying hydrodynamic conditions. Seasonal fluctuations, notably temperature, emerged as primary drivers shaping microbial activity and bioturbation, thereby impacting nutrient fluxes and microphytobenthos proliferation. These findings furnish foundational insights crucial for ecological management amidst climate change and forthcoming development initiatives within the Seine estuary.

Personal note: My role in this project, as a post-doctoral researcher, was to contribute on the microphytobenthic compartment. Beyond conducting my analyses on it, I had the opportunity to be at the forefront of project organization and communication between teams. Currently, I have contributed to the publication of three papers associated with this project (P1-P3). 

Abstract: The BARBES project aimed to evaluate the impact of benthic organisms (macrozoobenthos and microphytobenthos), as ecosystem engineers, on sediment dynamics on the mudflats of the Seine Estuary.

A major role of the benthos was identified in the Seine. The impact of microphytobenthic EPS (exopolysaccharides) and the entire macrozoobenthic community (the 6 studied species representing more than 95% of the total biomass) were integrated into the cross-shore hydro-sedimentary model MARS-2DV adapted to the Seine. This model took into account the long-term effects and the specific spatial distribution of each member of the benthic community on sediment dynamics. Simulations demonstrate the crucial functional role of biostabilizers.

Personnal note: My contribution to this project was related to the use of PAM fluorometry to measure the photosynthetic parameters on natural microphytobenthos biofilms. I have contributed to the publication of two papers associated with this project (P1 & P2). 

Abstract: The anthropogenic inputs in the Seine River make the Seine Estuary a highly eutrophic system with a high microalgae productivity that is often underestimated. Indeed, the phytoplanktonic and microphytobenthic compartments are frequently reduced to their chlorophyll content, providing only a static picture of these compartments. 

The PROUESSE project aimed to provide an estimation of phytoplanktonic and microphytobenthic primary production at high spatial and temporal frequencies in the downstream Seine estuary (i.e. salinity gradient).

By coupling 13C carbon incorporation and fluorescence measurements using Pulse Amplitude Modulated (PAM) fluorometers, the project enabled monthly high-frequency measurements of microalgae primary production throughout the entire year of 2015. Besides production measurements, the dynamics of exopolysaccharides was included and the diversity of the phytoplanktonic compartment was analyzed by combining microscopy, flow cytometry, and molecular biology. 

The project provided valuable information on the dynamics of both phytoplanktonic and microphytobenthic compartments and allowed for the estimation of autochthonous production.

Personal note: This project was the central focus of my PhD thesis. Five papers were published related to the phytoplankton compartment (P1-P5), and two on the microphytobenthic compartment in collaboration with the BARBES project (see above). Both compartments are integrated into my thesis manuscript (Thesis).