Discipline: Structuring of a migratory marine population using a multicriteria approach (including transcriptomics/proteomics).
Acronym: PHILOSEPIA
PhD supervision: Jean-Paul ROBIN – co-supervision by Joël HENRY
Doctoral contract funded by the Université de Caen Normandie
Team: UR7482 MERSEA “Marine Ecosystems and oRganisms reSEArch lab”
Doctoral School: ED 497 NBISE (Normandy Graduate School of Integrative Biology, Health, and Environment)
Context of the thesis:
The PHILOSEPIA PhD project is proposed within the MOBIDIC project:
“Magnetic fields and mOllusc BIoDiversity in the sea – understanding the Impacts of offshore wind farms in the Channel,” funded by the “biodiversity – offshore wind” program.
Description of the PhD/thesis project:
The scientific assessment of sustainable exploitation conditions for living resources and marine biodiversity relies on the study of management units (“stocks” or “exploitable phase of a population”). For modeling purposes, these units must be homogeneous not only genetically but also in terms of their biological and migratory cycles.
The cuttlefish Sepia officinalis has so far been assessed as a single stock, mostly harvested in winter in the central western Channel. The last investigation into genetic differences among breeders from coastal spawning areas (spring) dates back to the Interreg CRESH project (Shaw, 2012). It did not reveal significant differences between areas, although genetic structuring has been observed among sites around the Iberian Peninsula (Perez-Losada et al., 2007).
The “homing” hypothesis (or philopatry) for Channel cuttlefish (return of breeders to their hatching site) can now be tested using more powerful and discriminating genetic or genomic tools, along with a multicriteria approach, as applied to the squid Loligo forbesii (Sheerin et al., 2022). Depending on the degree of independence of coastal spawning grounds and the migration routes used, conservation diagnostics for this important fishery resource will need to be adapted.
Initially, the coastal areas where cuttlefish samples will be collected include Normandy (West Cotentin, Seine Bay, Côte d’Albâtre), before expanding to a broader geographic scale.
The criteria investigated will include the hologenome, transcriptomic polymorphism, molecular markers used for environmental DNA, as well as microchemical analyses (e.g., trace element composition along hard structure profiles).
Depending on the degree of independence of coastal spawning grounds and migration pathways, conservation assessments for this important fishery resource will need to be adapted.
Analysis of migration routes has already begun through the tracking of French trawlers equipped with the VMS system. This will be complemented by environmental DNA analyses to verify cuttlefish presence in hard-bottom areas inaccessible to trawling.
Initially, sampling zones will be located in Normandy (West Cotentin, Seine Bay, Côte d’Albâtre), before expanding geographically.
The criteria used will be based on:
- transcriptomic and proteomic polymorphism,
- molecular markers used for population genetics and environmental DNA,
- microchemical analyses of hard or calcified structures (Guo et al., 2025).
Candidate profile:
The ideal candidate will have a Master’s degree in marine sciences, marine ecology, or an equivalent field, with strong skills in molecular and proteomic approaches. An additional asset would be the ability to perform statistical analyses (such as PERMANOVA) using R, in order to compare samples based on the different criteria applied.
Participation in sample collection will involve fieldwork and time at sea.
Strong written and oral communication skills, particularly in English, are also required for disseminating results and presenting them to stakeholders and to the ICES expert group.
Start on October 1st, 2026, for a duration of 36 months, funded by a doctoral grant from the Université de Caen Normandie.
Process:
The submit file must include a CV, a cover letter, and transcripts from the past three years, sent electronically to:
jean-paul.robin@unicaen.fr and joel.henry@unicaen.fr
Deadline: Friday, May 15, 2026, at 12:00 PM
Selection process:
Selection Interview: May 18 to June 5 at the host laboratory
Oral Interview: June 22 (in person) by the doctoral school EDnBise
Start of the doctoral contract: October 1, 2026
Keywords: Homing (philopatry), proteomic polymorphism, genetic structure, multicriteria approach, stock management