Description of the thesis topic

(i) Project Context
The aim of this doctoral project is to develop a method for the early detection of an invasive aquatic plant species, Myriophyllum heterophyllum Michx. (Haloragaceae), based on an innovative application of environmental DNA (eDNA), as an alternative to traditional visual methods. This project responds to the need of the partner Voies Navigables de France (VNF), who have been observing the emergence of this species at various points in the navigable network for over 10 years. Myriophyllum heterophyllum hinders navigation, and once it is well established, management is limited to mowing it. Therefore, early detection is crucial for effective management, something traditional visual methods cannot achieve. The objectives of this doctoral work stem from a bibliographic review covering biological invasions and the use of eDNA in aquatic environments.
(ii) Study Objectives
This thesis is dedicated to detecting Myriophyllum heterophyllum, an invasive species already established in part of the Grand Est hydrographic network, using eDNA. The challenge is both methodological, fundamental, and operational. Some stages of this work must necessarily be carried out in parallel, but for clarity, the objectives are presented below in four stages:
(1) Develop the eDNA method to specifically detect the species (methodological aspects)
(2) Study the potential diversity of introduced populations by exploring the genetic diversity of the selected eDNA markers (fundamental aspects, including understanding dispersion and potential multiple introductions)
(3) Test the relationship between detection levels and plant biomass under controlled conditions (methodological and operational aspects)
(4) Test large-scale detection in the field to identify introduction points and/or fronts of progression.


(iii) Activities
• Design of specific primers and in silico testing of their specificity for Myriophyllum heterophyllum
• Genetic characterization of Myriophyllum heterophyllum: genetic diversity at the regional level, differentiation from sibling species, potential hybridizations
• Mesocosm tests for quantifying the species under controlled conditions using quantitative PCR (qPCR or ddPCR)
• Field deployment across the VNF North-East network
(iv) Desired Skills
The following skills are highly valued:
• Master's degree or engineering diploma in biology, ecology, geology, hydrology, or a related field
• Skills in collecting and analyzing biological and hydrological data
• Experience with environmental DNA protocol data analysis
• Proficiency with GIS tools for mapping
• Expertise in ecosystem landscape modeling based on environmental data and imaging
• Ability to work in a multidisciplinary team and collaborate with national and international partners
• Strong motivation for environmental research and biodiversity conservation
• Excellent communication skills in French, English, and/or German would be an asset
• A driver's license is also an important asset for frequent field trips

Work Context

The candidate will be hosted at the Image Ville Environment Laboratory (LIVE UMR 7362 Unistra CNRS ENGEES) located at the Institute of Botany. They will work with a team of ecologists with diverse skills, ranging from population genetics and environmental DNA to community studies and ecosystem restoration. This team is located very close to the rest of the laboratory (5 minutes' walk). Overall, LIVE conducts multidisciplinary research on urban, anthropized environments and hydrosystems, with the aim of understanding the impact of human activities on socio-ecosystems. This study is co-funded and carried out in partnership with Voies Navigables de France.

Constraints and risks

The candidate will work in aquatic environments and must be familiar with and adhere to safety instructions in such environments. Field missions will take place over several days away from home. In the lab, they will handle hazardous substances during molecular biology experiments and must follow relevant safety protocols.

Additional Information

The candidate will be register to the doctoral school 413 'Sciences de la Terre et de l'Environnement'