Engineer in geo-natural and anthropized environments

Job Details

You will be welcomed into the FREEMA team (Functioning and Restoration of Estuarine Ecosystems and Amphihaline Migratory Fish) of the EABX unit (Aquatic Ecosystems and Global Change). The mission will be carried out within the framework of the STURIO research project in support of the restoration program for the European sturgeon Acipenser sturio .

Most sturgeon species are threatened and are the subject of conservation and restoration programs. Restocking is one of the measures undertaken to restore declining species (IUCN 2013). This involves producing individuals in captivity for release into the wild at various stages to revive a weakened or extinct population. However, captive-bred fish are likely to have lower fitness than wild-caught sturgeon (Araki et al. 2008, Williamson et al. 2010). Therefore, it is necessary to find solutions to optimize the survival rate in the wild of juveniles bred in captivity. To achieve this, it is possible to modify rearing conditions (Berejikian et al. 2001) or training conditions (e.g., Braithwaite and Salvanes 2005) before release, or by improving release conditions in the natural environment (release stage, water chemistry, habitat, current speeds). The juveniles produced must be able to adapt to the conditions of their natural environment; but how do we define good adaptation to the natural environment and how do we assess it? 

In this work, we aim to explore the capabilities of captive-bred sturgeon larvae during their first days of life, before their first feeding, a stage that corresponds to one of the commonly used restocking stages. The objective is to characterize their swimming behavior (e.g., Capriello et al. 2019) and to develop an easily repeatable test that will ultimately allow for the routine characterization of captive-bred larvae. These larvae may originate from different crosses (different families), different breeding practices (e.g., using clay abrasion of the sturgeon eggshell), or different initial rearing practices (e.g., using water from a river or a municipal water supply). This will contribute to answering the question: how can we characterize what can be considered a good or poor-quality larva for restocking purposes?

In 2025, preliminary experiments were conducted to test the rearing of Danube sturgeon ( A. ruthenus ) larvae in ZebTECH-type enclosures up to 10 days post-hatching and to perform initial behavioral analyses using video tracking. In 2026, the candidate will actively participate in the assisted reproduction of Danube sturgeon ( A. ruthenus ), larval rearing, initial behavioral analyses using video tracking, biometric measurements under microscopy, and data analysis.

You will be specifically responsible for:

• Conduct a literature review related to the topic.
• Continue the analysis of the data acquired in 2025
• Actively participate in the experiment in 2026
• Analyze the 2026 data

Requirements

Licence/Master (Bac+3/5)

Recommended education: Bachelor's degree (3 years of higher education) to Master's degree (5 years of higher education) in aquatic ecology, aquaculture systems, or behavioral ecology.

Desired knowledge: Behavioral ecology, animal experimentation

Experience appreciated: Fish experiments

Required skills: Rigor, curiosity, ability to work in an experimental setting, biostatistics, literature review

Contact Information

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