A5073135942- Marine and coastal ecosystems
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Microbial Community Ecology and Physiology
- Geology and Paleoclimatology Research
- Oceanographic and Atmospheric Processes
- Marine Biology and Ecology Research
- Marine Invertebrate Physiology and Ecology
- Marine Toxins and Detection Methods
- Protist diversity and phylogeny
- Isotope Analysis in Ecology
- Arctic and Russian Policy Studies
- Environmental DNA in Biodiversity Studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Traumatic Brain Injury and Neurovascular Disturbances
- Marine Sponges and Natural Products
- Scientific Computing and Data Management
- Coastal and Marine Management
- Ocean Acidification Effects and Responses
- Marine and fisheries research
- Diatoms and Algae Research
- Marine and environmental studies
- Optical Imaging and Spectroscopy Techniques
- Education, sociology, and vocational training
- Physiological and biochemical adaptations
Centre National de la Recherche Scientifique
2016-2025
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2017-2025
Sorbonne Université
2016-2025
University of Bremen
2017-2025
Laboratoire d’Océanographie de Villefranche
2016-2020
Institut de la Mer de Villefranche
2019
Université de Montpellier
2013
Ifremer
2013
Abstract Predicting responses of plankton to variations in essential nutrients is hampered by limited situ measurements, a poor understanding community composition, and the lack reference gene catalogs for key taxa. Iron driver dynamics and, therefore, global biogeochemical cycles climate. To assess impact iron availability on communities, we explored comprehensive bio‐oceanographic bio‐omics data sets from Tara Oceans context products two state‐of‐the‐art scale models. We obtained novel...
Abstract The Gulf of Lions in the northwestern Mediterranean is one few sites around world ocean exhibiting deep open‐ocean convection. Based on 6 year long (2009–2015) time series from a mooring convection region, shipborne measurements repeated cruises, 2012 to 2015, and glider measurements, we report evidence bottom thick nepheloid layer formation, which coincident with sediment resuspension induced by bottom‐reaching events. This layer, presents maximum thickness more than 2000 m center...
Arctic Ocean sea ice cover is shrinking due to warming. Long-term sediment trap data shows higher export efficiency of particulate organic carbon in regions with seasonal compared without ice. To investigate this sea-ice enhanced export, we how different early summer phytoplankton communities seasonally ice-free and ice-covered the Fram Strait affect vertical dispersal microbes. In situ collected aggregates revealed two-fold diatom-rich regions, Phaeocystis region. Using microbial source...
Abstract. Mesoscale eddies are pervasive in the global ocean and suggested to play a significant role enhancing carbon export from surface deep ocean. However, their dynamic nature associated challenges of in-situ sampling have limited direct measurements flux within these features, leaving contribution uncertain. In-situ optical devices offer promising solution by providing high-resolution data on particle abundance size distribution (PSD) eddies, both vertically horizontally. Yet,...
The effects of climate change, including warming waters, loss sea ice habitat and the resulting changes in primary production, are inducing shifts marine communities across Arctic Ocean. marginal zone (MIZ) is a highly dynamic ecosystem transition between pack open ocean. It for wide range organisms, sympagic pelagic taxa, all which affected by changing physical dynamics MIZ. Here we use multi-marker (18S rRNA V1-2 COI Leray-XT) approach to investigate eukaryotic biodiversity upper water...
Sea ice in the Arctic Ocean has been undergoing dramatic changes during last two decades. In addition, water temperature of inflow Atlantic masses at gateway Fram Strait recently increased. Long-term data may help to evaluate impact these physical on biological processes surface waters. Over a 25-year period, and mostly summer, samples were collected discrete depths within uppermost 100 m other regions (AO) investigate chlorophyll (Chl a) particulate organic carbon (POC) standing stocks....
Abstract. The relative abundance of individual archaeal membrane lipids, namely glycerol dialkyl tetraethers (GDGTs) with different numbers cyclopentane rings, varies temperature, which enables their use as a paleotemperature proxy index. first GDGT-based index in marine sediments called TEX86 is believed to reflect mean annual sea surface temperature (maSST). TEX86L an alternative for “low-temperature” regions (<15 ∘C), where the original calibration shows larger scatter. However,...
Abstract The long‐term dynamics of microbial communities across geographic, hydrographic, and biogeochemical gradients in the Arctic Ocean are largely unknown. To address this, we annually sampled polar, mixed, Atlantic water masses Fram Strait (2015–2019; 5–100 m depth) to assess microbiome composition, substrate concentrations, oceanographic parameters. Longitude depth were major determinants (~30%) community variability. Bacterial alpha diversity was highest lower‐photic polar waters....
This study assessed the apoptotic process occurring in hemocytes of Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally during 48 h toxic algae. PSTs accumulation, expression 12 key apoptotic-related genes, as well variation number apoptosis was measured at time intervals experiment. Results show significant increase after 29 exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated mitochondrial...
Abstract The collection of zooplankton swimmers and sinkers in time‐series sediment traps provides unique insight into year‐round interannual trends population dynamics. These samples are particularly valuable remote difficult to access areas such as the Arctic Ocean, where from ice‐covered season rare. In present study, we investigated composition based on collected by at water depths 180–280, 800–1320, 2320–2550 m, over a period 16 yr (2000–2016) Long‐Term Ecological Research observatory...
The Fram Strait connects the Atlantic and Arctic Oceans is a key conduit for sea ice advected southward by Transpolar Drift northward inflow of warm Waters. Continued decline “Atlantification” are expected to influence pelagic–benthic coupling in as whole. However, interannual variability impact changing conditions on deepwater particle fluxes remain poorly characterized. Here, we present long-term sediment trap records (2000–2013) from mesopelagic (200 m) bathypelagic (2,300 depths at two...
Marine sinking particles sequester atmospheric carbon dioxide to the deep ocean via biological pump. Understanding how environmental shifts drive changes in microbial composition of particles, and these affect export organic matter from surface ocean, is critical, especially rapidly changing Arctic Ocean. Here, we applied next generation sequencing 18S 16S rRNA genes sediment trap samples around 200 m water depth eastern Fram Strait, covering a time frame more than one decade (2000-2012)....
Abstract Despite its wide spatial distribution and high abundance in the Mediterranean Sea, biology ecology of scyphozoan species Pelagia noctiluca remain poorly understood. This is mainly due to difficulties related sampling maintenance laboratory conditions. Thus, only a few studies exist on ecophysiology this jellyfish under As an example, maximum sizes individuals obtained previous culturing systems were not comparable ones found environment authors could obtain second generation. Here...
Abstract While Ocean modeling has made significant advances over the last decade, its complex biological component is still oversimplified. In particular, organisms in ocean system must integrate parameters to fit both physiological and ecological behaviors that are together very difficult determine. Such difficulty occurs for Pelagia noctiluca . This jellyfish a high abundance Mediterranean Sea could contribute several biogeochemical processes. However, gelatinous zooplanktons remain poorly...
Abstract. Eastern boundary upwelling ecosystems (EBUEs) are among the most productive marine regions in world's oceans. Understanding degree of interannual to decadal variability Mauritania system is crucial for prediction future changes primary productivity and carbon sequestration Canary Current EBUE as well similar environments. A multiyear sediment trap experiment was conducted at mooring site CBmeso (“Cape Blanc mesotrophic”, ca. 20∘ N, 20∘40′ W) highly coastal waters off Mauritania....
Abstract Arctic Ocean sea-ice cover is shrinking due to warming. Long-term sediment trap data show higher export efficiency of particulate organic carbon in regions with seasonal compared without sea-ice. To investigate this enhanced export, we how different phytoplankton communities seasonally ice-free and ice-covered the Fram Strait affect vertical dispersal microbes. In situ collected aggregates, combined microbial source tracking revealed that larger aggregates from under-ice diatom...
Eastern Boundary Upwelling Ecosystems (EBUEs) are associated with high biological productivity, fish catch and they highly contribute to marine carbon sequestration. Whether coastal upwelling has intensified or weakened under climate change in the past decades is controversially discussed different approaches (e.g. time-series of chlorophyll, wind, sea surface temperature, modelling experiments) have been considered. We present a record almost two particle fluxes (1991-2009) from ca. 600...
Globally, the most intense uptake of anthropogenic carbon dioxide (CO
Abstract Repeated measurements of benthic and pelagic parameters in the rapidly changing Arctic Ocean provide a unique insight into spatial interannual trends changes ecosystem. Here, we compiled biogenic biogeochemical collected from sediment cores at Long-Term Ecological Research Observatory HAUSGARTEN located Fram Strait. A total 21 stations were visited yearly over period 18 years (2002–2019). The time series highlighted an increase bacterial numbers for samples 50 days after peak...
Abstract. Eastern Boundary Upwelling Ecosystems (EBUEs) are among the most productive marine regions in world's oceans. Understanding degree of interannual to decadal variability Mauritania upwelling system is key for prediction future changes primary productivity and carbon sequestration Canary Current EBUE as well similar environments. A multiannual sediment trap experiment was conducted at mooring site CBmeso (= 'Cape Blanc mesotrophic', ca. 20° N, 20°40' W) high-productive Mauritanian...
Abstract. The relative abundance of individual archaeal membrane lipids, namely glycerol dialkyl tetraethers (GDGTs) with the different number cyclopentane rings, varies temperature, which enabled their use as paleotemperature proxy. first GDGT-based index in marine sediments called TEX86 is believed to reflect mean annual sea surface temperature (maSST). TEX86L an alternative proxy for low regions (
Understanding seasonal and multiyear variability of primary producers’ populations in the Mauritanian coastal upwelling system along northwestern African margin may help to predict future impact climate change (e.g., nutrient availability, productivity, phyto- zooplankton dynamics). For this, continuous, long time-series are required. A major challenge obtaining these is logistics associated with uninterrupted, in-situ sampling over several years. Sediment traps represent a reliable...