Christine Dupuy

La Rochelle Université · LIttoral ENvironnement et Sociétés (LIENSs)

This paper presents two metazoan zooplankton datasets obtained by imaging samples collected on the Bay of Biscay continental shelf in spring during the PELGAS (PELagique GAScogne) integrated surveys over the 2004–2019 period. The samples were collected at night with a 200 µm mesh-size WP2 net fitted with a Hydrobios (back-run stop) mechanical flowm...

Zooplankton analysis represents a bottleneck in marine ecology studies due to the difficulty to obtain zooplankton data. The last decades have seen the intense development of zooplankton imaging systems, to increase the zooplankton data spatio‐temporal resolution as well as enabling the combination of size, taxonomy, and functional traits in aquati...

Trophic interaction networks are notoriously difficult to understand and to diagnose. Such ecological networks welcome numerous feedbacks between species and populations and are not frozen at all, as soon as we observe them over a long enough term. These topological changes may be triggered by natural forcings (e.g. seasons) and/or by human influen...

Coastal marshes are submitted to huge management due to anthropogenic pressure and thus, it is essential to preserve their biodiversity, their ecological functions and the ecosystem services they can provide. This study investigates the diversity and abundance of planktonic communities (heterotrophic prokaryotes, heterotrophic protists, microphytop...

Marine environments are expected to be one of the most affected ecosystems by climate change, notably with increasing ocean temperature and ocean acidification. In marine environments, microbial communities provide important ecosystem services ensuring biogeochemical cycles. They are threatened by the modification of environmental parameters induce...

This paper presents two metazoan zooplankton datasets obtained by imaging samples collected on the Bay of Biscay continental shelf in spring during the PELGAS integrated surveys, over the 2004–2019 period. The samples were collected at night, with a WP2 200 µm mesh size fitted with a Hydrobios (back-run stop) mechanical flowmeter, hauled vertically...

Nouvelle-Aquitaine coastal areas will be affected by global change in 2100, particularly rising temperatures and ocean acidification. Although, microbial communities play key role in biogeochemical cycles, knowledge on how they are affected by global changes is poor. It is crucial to know the effect of global change on microbial communities in orde...

Although juvenile anguillid eels live in freshwater/estuarine habitats, and marine eels live in diverse ocean environments ranging from shallow-to-deep continental shelf areas and around islands to deep-benthic habitats and deeper meso- and bathy- pelagic zones, the larvae (leptocephali) of all species mix together in the ocean surface layer. All t...

Wetlands, especially marshes, support many services such as carbon catchment control or water purification led by primary producers such as phytoplankton and microphytobenthos (PB). The impact of the sedimentary compartment, as source and sink of essential nutrients for the water column, is often neglected in the study of their dynamics and water p...

Le projet PHARESEE a rassemblé un large panel d’équipes scientifiques autour de l’étude du fonctionnement écologique de la vasière nord de l’embouchure de l’estuaire. L’objectif était d’appréhender les interactions écologiques complexes entre processus hydro-sédimentaires, biologiques et biogéochimiques régulant le fonctionnement et l’évolution de...

Ecological baselines for the structure and functioning of ecosystems in the absence of human activity can provide essential information on their health status. The Glorieuses islands are located in the Western Indian Ocean (WIO) and can be considered as “pristine” ecosystems that have not been subjected to anthropogenic pressure. Their nutrient con...

In order to understand the effect of human practices on microbial mats organisation, the study aimed to investigate the biodiversity within microbial mats from exploited and abandoned salterns. Despite several attempts, archaeal 16S rRNA gene fragment sequences were not obtained, indicating that microbial mats were probably dominated by Bacteria wi...

Les effets du changement climatique représentent un défi pour notre société dans les prochaines décennies. Le groupe d'experts intergouvernemental sur l'évolution du climat (GIEC, 2014) prévoit que les systèmes marins seront parmi les zones les plus affectées. Elles feront face à de nombreuses pressions environnementales dues au changement climatiq...

The effects of herbicide diuron on photosynthesis and vertical migration of intertidal microphytobenthos (MPB) assemblages were investigated using chlorophyll fluorometry. The results shown diuron ≤ 60 μg L − 1 had no obvious effect on MPB vertical migration during 24 h indicated by consistent rhythm. Low concentration of 10 μg L − 1 diuron had no...

Salt marshes are under increasing anthropogenic pressures that have been reported to affect the diet of fish (e.g., change in prey composition and availability), eventually resulting in alterations in their nursery function. Most studies in Europe are based on fish gut content analysis, which only reflect a small proportion of pressures to salt mar...

From 2000 to 2016, substantial changes in biomass and community structure of small pelagic fish and mesozooplankton have been reported in the Bay of Biscay. Since significant relationships have been found between phytoplankton chlorophyll a and mesozooplankton as well as between phytoplankton chlorophyll a and shifts in sardine body condition, it w...

Abstract. Planktonic communities from Juan de Nova lagoon were submitted to a single exposure of diuron or naphthalene in triplicate outdoor 40-L mesocosms for 5 days. The study followed the temporal changes of the assemblages by determining abundances and taxonomic level of microbial (heterotrophic prokaryotes, picocyanobacteria, heterotrophic pro...

In freshwater systems, sediment can be an important source for the internal loading of PO4. The limiting character of this element in such system leads to consider this phenomenon in terms of eutrophication risks and water quality stakes. A four-months follow-up (January, March, April and May 2019) was carried out in a strong phosphate (PO4) limite...

Although it has been shown that trophic transfer of trace elements in oysters can be influenced by the diet, most of the studies investigating the ability of oysters to bioaccumulate trace elements from their diet are based on experiments using phytoplankton alone. Wild oysters feed also on large bacteria, ciliates or detritic organic matter. The p...

Microphytobenthos (MPB) at the sediment surface of intertidal mudflats are known to show a high spatial and temporal variability in response to the biotic and abiotic conditions prevailing at the mud surface. It makes long-term and large-scale monitoring of MPB Gross Primary Production (GPP) difficult to set up. In this study, we developed the firs...

Salt marshes are under high, and increasing, anthropogenic pressures that have notably been reported to affect the diet of several fish species, probably resulting in nursery function alterations. Most of the previous studies in Europe were yet based on gut content analysis of fish, which can be considered a snapshot of immediate impacts of salt-ma...

The gross primary production (GPP) of intertidal mudflat microphytobenthos supports important ecosystem services such as shoreline stabilization and food production, and it contributes to blue carbon. However, monitoring microphytobenthos GPP over a long-term and large spatial scale is rendered difficult by its high temporal and spatial variability...

Digestion-resistant bacteria (DRB) refer to the ecological bacterial group that can be ingested, but not digested by protistan grazers, thus forming a specific type of bacteria-protist association. To test the hypothesis that the environment affects the assembly of DRB in protists, a mixotrophic ciliate, Paramecium bursaria, and a heterotrophic cil...

This study aims at (1) experimentally estimating first sexual maturation of the European sardine S. pilchardus, (2) using the results to calibrate existing bioenergetic models. During the 183 days-experiment, fish growth and body condition were assessed by biometry, and gonads were weighed when present. Age, total length and wet weight at first mat...

Estuarine intertidal flats strong biological productivity is mainly based on the activity of benthic microalgae communities or microphytobenthos (MPB), mostly dominated by diatoms. Epipelon is a major MPB growth form comprising motile species, which perform repeated "vertical migration" patterns in the upper sediment layers according to tidal and d...

The ecology of leptocephali remains poorly known but they appear to feed on marine snow that can vary spatially and temporally according to the food web dynamics. This study provided new information about the position of leptocephali within the functional structure of microbial plankton and other food web components of the western South Pacific (WS...

Diet is an important route of mercury (Hg) uptake in marine organisms. Trophic transfer of Hg throughout the food webs may be influenced by various factors, including diet and Hg speciation. Bivalves such as oysters are widely used as bioindicators of trace element pollution such as Hg. Nevertheless, our current knowledge regarding their ability to...

The increase in extreme events such as storms is one of the major threats that coastal ecosystems will have to face in the near future. In such a context, both maturation and ecological successions processes remain at the core of ecology to better anticipate the changes to ecosystem biodiversity and functions facing environmental stressors. However...

The functional diversity of two planktonic functional compartments, the nano-microphytoplankton and the mesozooplankton was used in order to better understand i) the drained marshes functioning and their related ecological functions, ii) the impacts of human control (replenishment) and human activities on the catchment basin (urbanization and catch...

Evaluations of the functioning of benthic marine food webs could be improved by quantifying organic matter fluxes from the meiofauna to higher trophic levels. In this study, we measured the simultaneous ingestion of meiofauna and macrofauna by common dwellers of a tropical intertidal mudflat on the coast of Amazonia. The meiofauna and macrofauna (t...

Estuarine intertidal flats strong productivity is mainly based on the biological activity of benthic microalgae communities, or microphytobenthos (MPB), mostly dominated by diatoms. Epipelon is a major MPB growth form comprising motile species which undergo vertical so-called ‘migration’ patterns in the upper sediment layers. Typically, at the begi...

The slipper limpet Crepidula fornicata is an emblematic invasive species along the northeast Atlantic coast. This gregarious gastropod lives in stacks of several individuals and forms extended beds in shallow subtidal areas. The effects of this engineer species on the colonized habitat can be physical (e.g., presence of hard-shell substrates with u...

Microphytobenthos (MPB) from intertidal mud- flats are key primary producers at the land–ocean interface. MPB can be more productive than phytoplankton and sus- tain both benthic and pelagic higher trophic levels. The ob- jective of this study is to assess the contribution of light, mud temperature, and gastropod Peringia ulvae grazing pres- sure i...

The initial objective of the PELGAS integrated survey was to assess the biomass of small pelagic fsh in the Bay of Biscay in spring. Sampling has been extended to study the spatial structure and dynamics of the pelagic ecosystem in springtime. The PELGAS survey has produced since 2000 long-term time-series of spatially-explicit data and indices, de...

Trophic ecology is the study of feeding interactions and food acquisition by organisms. It includes the causes and consequences of those behaviours at all levels of biological organisation. As a field of research, it crosses many disciplinary boundaries and provides knowledge that is pertinent to many other areas of ecology. Here we list and catego...

The phylogenetic assignment of archaeal communities is constantly evolving, and the recent discovery of new phyla that grouped into superphyla has provided novel insights into archaeal ecology and evolution in ecosystems. In intertidal sediments, archaea are known to be involved in key functional processes such as organic matter turnover, but the e...

Microphytobenthos (MPB) from intertidal mudflats are key primary producers at the land-ocean interface. MPB can be more productive than phytoplankton and sustain both benthic and pelagic higher trophic levels. The objective of this study is to assess the contribution of light, mud temperature, and gastropod Peringia ulvae grazing pressure in shapin...

Le projet PAMELi (Plateforme Autonome Multicapteurs pour l'Exploration Littorale interdisciplinaire) porte sur l'observation répétée des paramètres environnementaux tels que les paramètres physico-chimiques de la colonne d'eau, la qualité des eaux, la hauteur d'eau et la bathymétrie précise à l'aide d'un drone marin. Ce projet sera mis en place dan...

Le littoral est un système dynamique complexe régi par les interactions entre divers processus physiques, biologiques ou humains. Mieux comprendre ces interactions nécessite l'acquisition simultanée et répétée de données de divers capteurs. PAMELi sera un drone marin destiné à acquérir des données scientifiques multidisciplinaires en domaine littor...

Mesozooplankton can be considered the most important secondary producers in marine food webs because they hold an intermediate position between the phytoplankton assemblage and the upper trophic levels. They also are a robust indicator of climatic and hydrological conditions. We conducted an analysis of the interannual variability of the spring mes...

In intertidal sediments, circadian oscillations (i.e., tidal and diel rhythms) and/or depth may affect prokaryotic activity. However, it is difficult to distinguish the effect of each single force on active community changes in these natural and complex intertidal ecosystems. Therefore, we developed a tidal mesocosm to control the tidal rhythm and...

A model was developed to reproduce temporal variation of microphytobenthos (MPB), bacteria, and nutrients in the first centimeter of sediment. Physiological processes of MPB such as vertical migration and EPS (Extracellular Polymeric substance) production were integrated in the model. Endogenous process represented by the C:N ratio of MPB was set a...

This paper is a practical contribution to two important debates raised by the implementation of marine ecosystem based management: (i) which ecosystem data can be provided by a fisheries survey optimised for ecosystem monitoring; and (ii) how to combine/select potential indicators to derive useful information on marine ecosystem status and dynamics...

Coccolithophore blooms occur regularly from April to June in the Bay of Biscay where they have been observed for many years from ocean-colour imagery thanks to the ability of their calcite plates to scatter light. They are easily depicted on interpolated images of non-algal Suspended Particulate Matter (SPM) derived from satellite reflectance data...

To explore some aspects of mesozooplankton functional diversity, this study quantified energy density during the springtime in the Bay of Biscay both between different species and between different size-classes. Energy densities of copepod species (Centropages typicus, Anomalocera patersoni, Calanus helgolandicus, and Labidocera wollastoni), as wel...

The Pélagiques Gascogne (PELGAS) integrated survey has been developed by a multidisciplinary team of Ifremer and La Rochelle University scientists since 2000, joined by commercial fishermen in 2007. Its initial focus was to assess the biomass and predict the recruitment success of anchovy in the Bay of Biscay in spring. Taking advantage of the spac...

Integrated marine survey series such as PELGAS provide comprehensive geo-referenced data over large sea areas in major ecosystem components with defined biological resolution and spatio-temporal sampling scale. These data enable to develop product at different levels of biological organization and spatial scale that are useful for ecosystem integra...

To implement a new view point on mesozooplankton features in trophic studies framework, the present study aims at quantifying the energy density of mesozooplankton at the species level but also spatially. Samples were collected at springtime in the Bay of Biscay considering both taxonomic and size-classes diversity during PELGAS surveys in 2013 and...

Microphytobenthos communities of different sediment types were investigated in intertidal flats of the coastal area around La Rochelle (Pertuis Charentais, France) in July 2014 and January 2015. Biotic variables of biomass, abundance and species composition of microphytobenthos were evaluated together with environmental variables, including irradia...

The extreme dynamics of the Amazonian coast and associated mudbanks raises questions about their unknown resistant infauna. In order to fill the gap, we investigated the seasonal variations of species composition, abundance and population structure of Tanaidacea in two dynamic mudbanks near the coast of French Guiana. Despite the low species richne...

In tropical South America, the mudflats of the Amazonian coast are unique because of their large size and unrivaled migration dynamics. On Guiana’s coast, macrofaunal communities are believed to be well-adapted to these dynamic conditions. In this study, the benthic macrofauna was sampled in April 2012 in the Awala-Yalimapo region of western French...

Disturbance strongly impacts patterns of community diversity, yet the shape of the diversity-disturbance relationship remains a matter of debate. The topic has been of interest in theoretical ecology for decades as it has practical implications for the understanding of ecosystem services in nature. One of these processes is the remineralization of...

A prey–predator experimental setup was conducted in a shallow coastal ecosystem characterized by a bare intertidal mudflat to test if benthic biofilm resuspension causing microalgae inputs and carbon export toward nanoflagellates would favour the highest planktonic trophic level (i.e. mesozooplankton) when nutrient concentrations are high in the wa...

The feeding ecology of leptocephali has remained poorly understood because they apparently feed on particulate organic matter (POM), which varies in composition, and it is unclear which components of the POM they assimilate. The δ13C and δ15N stable isotope (SI) and fatty acid (FA) compositions of 3 families of leptocephali and POM were compared in...

The North Atlantic coast of South America is influenced by the Amazon River. This coast is considered the muddiest in the world due to the enormous suspended sediment input from the Amazon River. The mobility of the sediment imposes a geomorphological dynamic with a rapid change of shoreline and fast alternation of facies types of the sediment. Thi...

The spatial and temporal patterns of diversity, community structure, and their drivers are fundamental issues in microbial ecology. This study aimed to investigate the relative importance of spatial and seasonal controls on the distribution of nitrogen cycling microbes in sediments of estuarine tidal flats, and to test the hypothesis that metals im...

Parasitological data are increasingly used to provide information on host populations, trophic interactions and free-living biodiversity. In the present study, we investigated parasitic helminths in Sardina pilchardus and Engraulis encrasicolus from the Bay of Biscay (north-east Atlantic). In addition, helminths infecting E. encrasicolus were revie...

Carbon and nitrogen stable isotopes are increasingly used to study the trophic relationships in marine ecosystems. The pilchard Sardina pilchardus is a key species among small pelagic fish in the functioning of marine pelagic food webs in the Northeastern Atlantic Ocean. Pilchards were caught in 2014 in the Bay of Biscay and were maintained during...

In intertidal benthic ecosystems, environmental conditions shaped the inhabiting prokaryotic communities during emersion period. Aiming at simplifying the complexity of intertidal mudflats, we developed a tidal mesocosm approach allowing sampling the top 10 cm of sediment. In this study, we removed macrofauna that can be the major prokaryotic graze...

Which information provided by helminth parasites about feeding patterns of their host and free-living biodiversity in ecosystem? Parasitological research was made in all the organs and tissues of 52 E. encrasicolus and 49 S. pilchardus caught in spring 2012 in the Bay of Biscay by PELGAS (PELagique GAScogne, an accoustic survey to estimate the aver...

The strong biological production of estuarine intertidal flats is mainly supported by benthic diatoms in temperate areas. Their photosynthetic productivity is largely driven by changes in light intensity and temperature at the surface of sediment flats during emersion. The impact of an increase in salinity of the upper-layer sediment pore-water dur...

Small pelagic fish represent an essential link between lower and upper trophic levels in marine pelagic ecosystems and often support important fisheries. In the Bay of Biscay in the north-east Atlantic, no obvious on trolling factors have yet been described that explain observed fluctuations in European sardine Sardina pilchardus and European ancho...

We conducted a weekly survey at two stations of a French coastal marsh during the transition from winter to spring, when the sea lock gates were closed. Field measurements and laboratory experiments were combined in order to describe the structure and dynamics of planktonic food webs. Physico-chemical parameters were measured, and food web typology...

Relationships between bacteria, microphytobenthos and extracellular polymeric substances (EPS) that make up microbial biofilms over bare mudflats were investigated at an hourly frequency during two 14-day spring-neap cycles in winter and summer 2008. Bacterial abundance and total chl a concentration were lower in summer (0.78×108±SD 0.39×108cell.m-...

The quantification of overall microphytobenthos productivity should include the export of biomass from the intertidal zone during high tides, which implies refined estimates and concepts of erosion parameters. For the first time, the export of microphytobenthic cells was assessed over an intertidal mudflat in the Marennes-Oléron bay, France, during...

Leptocephali are unusual in many ways compared to other fish larvae, and their feeding ecology appears to be based on consuming particulate organic matter, such as marine snow, as their food source. Sampling surveys for leptocephali in the Mascarene Ridge area of the western Indian Ocean and in the western South Pacific were used to examine the sta...

In intertidal marine sediments, characterized by rapidly fluctuating and often extreme light conditions, primary production is frequently dominated by diatoms. We performed a comparative analysis of photophysiological traits in 15 marine benthic diatom species belonging to the four major morphological growth forms (epipelon (EPL), motile epipsammon...

In shallowmacrotidal ecosystemswith large intertidalmudflats, the sediment–water coupling plays a crucial role in structuring the pelagicmicrobial foodweb functioning, since inorganic and organicmatter and microbial components (viruses and microbes) of the microphytobenthic biofilm can be suspended toward the water column. Two experimental bioassay...

The relative abundances of nitrifying, denitrifying and anammox prokaryotes in sediments of three hypernutrified estuarine tidal flats of Laizhou Bay, Bohai Sea, China were investigated. Quantitative PCR estimates indicated that in most cases archaeal (AOA) amoA genes were more abundant than bacterial (AOB) amoA genes, and ratio of AOA/AOB was corr...