Employer: Sorbonne University
Location: Villefranche Oceanography Laboratory, 181 chemin du Lazaret, Villefranche sur mer
Contract type: 6 months
Employment status: Full-time
Zooplankton plays a central role in the ocean’s biological pump and carbon cycle, contributing to the export of organic matter to deeper layers through fecal production, particle sedimentation, and vertical migration. It thus influences the quantity and quality of particles exported to the depths. These particles, whether aggregates or feces, exhibit morphological and functional diversity that determines their sedimentation rate and thus their contribution to carbon sequestration.
The equatorial Atlantic Ocean is characterized by high primary productivity, fueled by an upwelling system that brings cold, nutrient-rich water to the surface. This production supports the abundance and diversity of zooplankton and regulates the flow of carbon to the depths. The distribution of chlorophyll-a at the surface shows a spatial gradient from west to east across the tropical Atlantic, reflecting varying intensities of upwelling and local environmental conditions.
The spatial and seasonal variability of this region directly influences the composition and dynamics of zooplankton communities. Studying these gradients and variability is essential to understanding how zooplankton distribution modifies the production and diversity of exported particles, and thus the efficiency of carbon sequestration along the Atlantic equator.
This study aims to identify the factors explaining the spatio-temporal variability of zooplankton communities in terms of taxonomy and morphology along two equatorial transects and to identify the links between their taxonomic and morphological structure and the diversity of the particles produced. It will also assess their influence on carbon export and sequestration under contrasting conditions (productive vs. unproductive periods).
The student will use data acquired at the equator using an Underwater Vision Profiler (UVP) camera, which measures the concentration, size, and type of particles (>100 μm) as well as zooplankton at depths of up to 4,000 m. These observations will be supplemented by images and measurements from ZooScan in order to characterize the composition and abundance of zooplankton in detail. The in situ data will also be cross-referenced with satellite products such as surface temperature and chlorophyll concentration in order to assess the vertical structure and biomass of zooplankton in different environmental contexts. Finally, advanced classification tools such as machine learning will be used to explore the links between plankton communities, particle diversity, and carbon flux, complementing more traditional analytical approaches adapted to large oceanographic datasets.
The student will work on this interdisciplinary dataset using both recent machine learning techniques for organism classification and more conventional analysis methods adapted to large oceanographic datasets. The objective is to quantify the spatial and temporal variability of zooplankton communities along two transects in the Atlantic equator, as well as to compare the influence of taxonomic and morphological composition on carbon export during productive and unproductive seasons.
Required skills
– Strong interest in marine research and science.
– Proficiency in Python.
– Basic knowledge of ecology, marine biology, or oceanography.
-Language French or English
Required documents
1. Cover letter
2. Curriculum vitae
3. Names and contact details of one or two people who can provide references.
Interested candidates can contact joelle.habib@imev-mer.fr for more information and should send the required application documents by email to the same address.
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