Les missions du poste
PhD : Plastiphysh- Investigate the potential contamination of aquaculture-derived plastics by toxic microalgae and their phycotoxins, and their impact on fish larvae
Closure date for receipt of applications : 19/05/2025
Who are we?
The thesis project is a collaboration between four laboratories with the resources needed to carry out the planned experiments and analyses. You will participate in scientific networks such as GDR Plastiques, Environnement, Santé, ICHA, GDR OMER for the presentation of results at national and international conferences. Our consortium is composed of Ifremer/PHYTOX (Z. Amzil director HDR, A. Caruana, thesis co-supervisor), Ifremer/MARBEC (M.L. Bégout, thesis co-director, HDR,), ICGM (V. Lapinte, HDR), UMR MARBEC (X. Cousin HDR, E. Masseret, HDR).
- PHYTOX Unit, Ifremer Nantes has extensive expertise and numerous facilities in the chemistry of phycotoxins (LC-MS/MS, LC/HRMS...) and the ecophysiology of toxin production by microalgae (room culture, Phyto-PAM, flow cytometry...).
- Ifremer MARBEC Unit, is studying the physiological effects of microplastics on fish models. The marine experimental platform of Palavas offers all the necessary experimental facilities for the production of fish and their exposure according to the methods described above and in compliance with the associated ethical rules.
- ICGM de Montpellier (UMR 5253 CNRS) is specialized in materials chemistry, with a particular focus on plastics : manufacturing processes for plastic samples and their chemical (NMR, UV, FTIR, GPC, Maldi-Tof), physico-chemical (DSC, ATG, ATG-MS, contact angle) and mechanical (tension, compression, DMA) characterization.
- UMR MARBEC (University of Montpellier) studies marine ecology, marine biodiversity and its uses. IT has expertise in the study of toxic microalgae and a strain collection of Mediterranean toxic microalgae.
What is the subject of the thesis ?
Plastic debris are widely distributed in the marine environment and may affect the ecosystem, because of their toxicity via released constituents, and via the adsorption and transport of contaminants and pathogens. To date, little is known about the interactions between plastic debris and microalgae toxin and about the consequences on the trophic chain. In this project you will study (i) the safety or the toxicity of plastics derived from aquaculture on toxic microalgae that form harmful blooms on the French coast, (ii) the potential role of vectors for selected plastic depending on cell adhesion abilities of algae and their phycotoxins, and (iii) the phycotoxin transfer to fish larvae/juveniles via contaminated plastic ingestion, and the synergic impact of both contaminations on fish. (iv) the chemoattractant role that DMS, another compound produced by microalgae, could play in the plastic ingestion by fish.
What will your mission BE?
This project is in line with the One health scientific challenges and the Healthy and nourishing ocean flagship theme of Ifremer. HABs species and their phycotoxins as well as plastic pollution are a threat for human health and marine life through their potential contamination of seafood and their accumulation in the trophic chain. Moreover, plastic is likely to BE a vector for HAB species and their phycotoxins, combining the threat of both factors. The project aims to investigate the pressure of anthropogenic pollutant such as plastic on microalgae growth and physiology, and the combination of plastic and phycotoxins on fish larvae survival and development. The project particularly focuses on aquaculture-derived plastics to assess how the aquaculture material may induce a pressure and a risk of contamination for exploited species (fish larvae) and for the ecosystem. The results will open discussion on requirements and solutions to support sustainable fishing and aquaculture.
Your mission will BE to answer the following questions :
- Can aquaculture-derived plastics BE toxic to microalgal species?
- Can plastics attach and convey HABs species and their phycotoxins as an artificial vector?
- How do toxin-contaminated plastics affect fish larvae?
- Is plastic ingestion by fish favoured by the chemoattractant DMS?
What will your activities BE?
Your activities will BE organised into four tasks :
Task 1 Plastic toxicity for microalgae. In order to determine whether the plastic has a toxic effect or beneficial effect as a support for algal fixing, microalgal species will BE cultured in flasks containing plastics (film strips/ particles). The algal growth and its photosynthetic activity will BE monitored in the culture to assess their survival and development in the presence or absence of aquaculture-derived plastics (PE, PA, PP).
Task 2 Plastic colonization by microalgae. Several non-axenic HABs strains such as Alexandrium (pelagic), Vulcanodinium or Ostreopsis (benthic) will BE cultured in the presence of plastics. If the culture grows in the presence of plastics, the adhesion of algal cell will BE monitored by observation of plastic fragments under light and epifluorescence microscopy.
Task 3 Toxins adsorption on plastics, Adsorption kinetics of toxins on plastics (strips and particles) will BE tested using toxin standards in seawater. Toxin analyses will BE performed by LC-MS/MS (dissolved fraction and toxins adsorbed on plastic). Toxins with diverse chemical properties and relevant for French waters will BE tested (e.g. okadaic acid or pectenotoxins, pinnatoxins, saxitoxins and palytoxins). Plastic surfaces will BE characterized by contact angle measurements, TEM microscopy, integrity of the material by SEC chromatography, FTIR spectroscopy and DSC.
Task 4 Toxin transfer to fish by microplastics (MPs). Feeding experiments will BE conducted with larvae/early juveniles of the biological model Oryzias melastigma and the Mediterranean aquaculture species Dicentrarchus labrax. Short exposures will BE performed by feeding larvae with toxin-contaminated MPs in comparison with virgin MPs or dissolved toxins. The selection of MP and toxin will result from experiment of task 3. Toxin content in the fish will BE measured by LC-MS/MS and MPs counted to determine plastic ingestion. To evaluate the influence of DMS on MPs uptake, feeding behaviour, swimming behaviour and growth will BE monitored (video-tracking) upon exposure of fish to DMS-adsorbed or virgin MPs.
Key words
Phycotoxins, toxic microalgae, HABs, plastics, trophic chain, fish, health risk
How are your activities organised?
- 100% activity
- Based two years in the PHYTOX Unit at Ifremer in Nantes, and one year at the Ifremer station in Palavas and Charles Gerhardt Institute in Montpellier.
Le profil recherché
Who are you?
- Master 2
- Spécialised in biological marine sciences, ecophysiology, ecotoxicology, biology
- Interest in environmental issues including plastic pollution
You have the following skills, knowledge and experience :
- Laboratory experiments
- Experiments with biological organisms (plant and animal)
- Microbiology
- Analytical chemistry
- Statistics
You have the following qualities :
- Thoroughness, curiosity, ability to summarize
- Excellent writing skills
- Autonomous and able to work as part of a team
- Good level of English
Bienvenue chez Ifremer
Join Ifremer, an ally of planetary well-being, to gain a better understanding of and better protection for the ocean.
From the abyss to the surface, from the coast to the open SEA, Ifremer is the French research institute that is wholly dedicated to the Ocean. Its teams carry out research, innovate and produce expert reports to protect the ocean, exploit its resources in a responsible manner and shares marine data.
Ifremer contributes its scientific expertise to throw light on public policies and develops solutions drawn from the ocean to meet the challenges of the ecological transition. Ifremer is the operator of France's oceanographic fleet with its shipbuilding subsidiary Genavir, and imagines, designs and deploys leading edge technological means to solve the ocean's mysteries.
Join our teams, made up of 1500 scientists and research support staff, present all along the coastal areas of France and French overseas territories.
www.ifremer.fr
Infos complémentaires
What are your benefits?
- PhD is a real opportunity to work on Ifremer's scientific and technological priority themes. IT entitle the holder to a gross monthly salary of 2300 Euros gross for a period of 3 years, which cannot BE combined with other scholarships.
- We have a teleworking agreement and our staff have 12 comp time days and supra statutory leave.
- We allocate a significant budget to developing skills, through individual or collective training actions.
- We have a CSR policy inspired by the purposes of the institute (sustainable mobility allowance, etc.)
How to apply for this position?
Your application file must include :
- A curriculum vitae
- A cover letter
- A reference letter
- An academic transcript (Bachelor + Master 1 and first semester Master 2)
The deadline for applications is May 19th, 2025. Nevertheless, we strongly urge you to let us know as soon as possible of your intention to apply, by contacting the subject supervisor : Amandine Caruana ; Zouher Amzil.
In parallel, please submit your application to the doctoral school : ED VAAME
Doctoral students' contracts will start as of October 6th, 2025, subject to the obtention of co-financing by the team and to the submission of administrative documents by the candidate authorizing Ifremer to recruit the doctoral student (certificate of completion of the Master 2 or engineering degree + visa for foreign doctoral students outside the EU).
What are the next steps?
The recruitment process takes place in 3 steps :
- A pre-selection of applications
- An interview with supervisors
- An audition before the jury of the doctoral school ED VAAME
