CONTEXT:
In France, many pressures threaten diadromous species and lead to their decline, some being even in danger of extinction. Dampening pressures on these migratory species is thus of great concern for their conservation. To restore the aquatic continuity near dams, fishways and fish ladders are built to allow the passage of fish (hydroelectric plants, dams and water intake). However, these sites constitute bottlenecks where diadromous species like shads Alosa alosa and Alosa agone, sea lamprey Petromyzon marinus or Atlantic salmon Salmo salar have to deal with an opportunistic top predator, the catfish Silurus glanis. With its big size (up to 2,7 m and 150 kg), this new predator quite recently (re)introduced in western Europe (Cucherousset et al, 2018), is almost the only one able to prey upon these migratory species at the adult life stage in rivers. In France, since the 2010s, scientific studies have shown that it can exert a significant local predation pressure on amphihalin fish, particularly in spring during their upstream migration to breeding sites. For example, in some rivers such as the Garonne, Dordogne and Loire (Guillerault et al, 2018 ; Boulêtreau et al, 2020 ; Trancart et al. 2023), this pressure is close to 80% on sea lamprey, considerably reducing the number of breeding individuals.
OBJECTIVES:
In France, some fishways have been equipped with video-counting stations since the 1990s, enabling continuous monitoring of their use by fish species. The aim of the first axis of this work will be to exploit these time series (Legrand et al, 2020) to characterize the temporal patterns of fishway frequentation (annual, seasonal, hourly) by catfish, amphihalin species and other holobiotic species, and to quantify the degree of synchronism between catfish and their potential preys. The influence of environmental conditions, such as water temperature or flow rate, on use of fishway will also be taken into account. This analysis will provide an overall view of what is going on over the metropolitan area, and will enable to identify priority basins/sites and key periods (season, time of day) at which management actions could be led to reduce catfish pressure on migratory species.
Among fishes, catfish has excellent hearing capabilities thanks to its Weber apparatus (Ladich, 2023). It emits low-frequency impulse sounds and reacts to sound. Typically, catfish are attracted when shads violently strike the water surface with their caudal fin during spawning bulls. The clonk fishing technique, which consists of attracting catfish by emitting a characteristic sound at the water’s surface, also illustrates this very well. However, in intensively fished areas, the clonk, on the contrary, scares them away, underlining the catfish’s capacity to learn. In this second line of work, we propose to use these learning capacities to test the possibility of conditioning catfish behaviour by phonotaxis (Putland and Mensinger, 2019). Attractive acoustic stimuli will be broadcast in the water and associated with an unpleasant experience, such as a mild electric shock, so that the catfish learns to associate the attractive sounds with a noxious stimulus and, thus conditioned, ends up fleeing just by listening to the initially attractive signals. The possibilities of conditioning and its effectiveness (duration, individual variability, habituation) will be assessed in an experimental natural lake where the movements of a pool of catfish will be continuously monitored by acoustic telemetry (Westrelin et al, 2022). At the same time, the method will be tested on the Garonne, in the vicinity of a fishway, in a real-life situation, and evaluated using an acoustic camera. The aim will be to produce a tool that can be deployed on other sites.
TRAINING AND SKILLS REQUIRED:
We are looking for a student with a solid background in aquatic ecology (Masters 2 or equivalent), with a particular interest in fish and behavioral studies. The student should be motivated by both data analysis (exploration, synthesis and statistics) and field experiment with a strong team spirit, two essential components of this work. The student will be keen to generate new knowledge for application by managers. Fluency in English is essential.
TRAINERS :
Thesis Director (Doctoral School 251) : Samuel Westrelin (INRAE/RECOVER)
Co-directors : Romain Roy (EDF/LNHE) and Vincent Médoc (CRNL/ENES)
LABORATORIES :
The student will divide her/his time between Chatou (EDF/LNHE) and Aix-en-Provence (INRAE/RECOVER).
-Laboratoire National d’Hydraulique & Environnement (LNHE) :
EDF R&D
6 Quai Watier
78401 CHATOU Cedex
Electricité de France is an industrial company producing electricity, particularly hydroelectric power. Through the activities of its research and development center (EDF R&D) and its Laboratoire National d’Hydraulique et Environnement (LNHE), the company has long been keen to increase its knowledge in the field of migratory fish protection (development of fishways and fish ladders) and of the impacts generated by hydroelectric structures. In fact, since the 1980s, the LNHE has been involved in the design, construction and evaluation of numerous fishways, and is a key player in the development of knowledge in the field of ecological continuity.
-Equipe FRESHCO
INRAE/RECOVER
3275 Route de Cézanne
CS 40061
13182 Aix en Provence Cedex 5 – France
The National Research Institute for Agriculture, Food and Environment (INRAE) is a public research institute bringing together a working community of 12,000 people, with 272 research, service and experimental units, located in 18 centers throughout France. Within the research unit RECOVER (Risques, ECOsystèmes, Vulnérabilité, Environnement, Résilience) of the INRAE laboratory in Aix-en-Provence, the FRESHCO team (Fonctionnement et REStauration des Hydrosystèmes COntinentaux) conducts research on the functioning of continental hydrosystems, particularly under multiple anthropic pressures, focusing on scales ranging from community to individual. Working closely with the OFB (French Biodiversity Agency) within the pole ECLA (Lacustrine Ecosystems), this research aims to respond to societal demand on current issues relating to the management of freshwater ecosystems.
-CRNL/ENES
The Lyon Neuroscience Research Center (CRNL) brings together the multidisciplinary expertise of ~450 members to decipher brain organization, cognitive functions, mental states, and related brain disorders. ENES (Sensorial Neuro-Ethology Team) focuses on bioacoustics, the science of animal and human sound signals. Rooted in ethology (the study of behavior), ENES has a long tradition in neuroscience (mechanisms of acoustic communication) and ecology (impact of abiotic and biotic environments on the evolution of communication; bioacoustic tools for biodiversity assessment).
STARTING DATE: between June and October 2025
DURATION: 36 months
GROSS SALARY : at least 2 960 € per month
APPLICATION DEADLINE : 31 January 2025
TO APPLY : edf.fr/edf-recrute/offre/detail/2024-123615
Send a CV and a motivation letter to romain-r.roy@edf.fr, samuel.westrelin@inrae.fr et vincent.medoc@univ-st-etienne.fr
REFERENCES:
Boulêtreau, S., T. Fauvel, M. Laventure, R. Delacour, W. Bouyssonnié, F. Azémar & F. Santoul, 2020. “The giants’ feast”: predation of the large introduced European catfish on spawning migrating allis shads. Aquatic Ecology doi:https://doi.org/10.1007/s10452-020-09811-8.
Cucherousset, J., P. Horky, O. Slavik, M. Ovidio, R. Arlinghaus, S. Boulêtreau, R. Britton, E. Garcia-Berthou & F. Santoul, 2018. Ecology, behaviour and management of the European catfish. Reviews in Fish Biology and Fisheries 28:177-190 doi:https://doi.org/10.1007/s11160-017-9507-9.
Guillerault, N., S. Bouletreau & F. Santoul, 2018. Predation of European catfish on anadromous fish species in an anthropised area. Marine and Freshwater Research 70:682-686 doi:https://doi.org/10.1071/mf18206.
Ladich, F., 2023. Hearing in catfishes: 200 years of research. Fish and Fisheries doi:https://doi.org/10.1111/faf.12751.
Legrand, M., C. Briand, L. Buisson, G. Artur, D. Azam, A. Baisez, D. Barracou, N. Bourré, L. Carry, A.-L. Caudal, F. Charrier, J. Corre, E. Croguennec, S. Der Mikaélian, Q. Josset, L. Le Gurun, F. Schaeffer & P. Laffaille, 2020. Contrasting trends between species and catchments in diadromous fish counts over the last 30 years in France. Knowl Manag Aquat Ecosyst:7.
Putland, R. L. & A. F. Mensinger, 2019. Acoustic deterrents to manage fish populations. Reviews in Fish Biology and Fisheries 29:789-807 doi:https://doi.org/10.1007/s11160-019-09583-x.
Trancart, T., E. Robin, A. Acou, Associations agréées des pêcheurs professionnels, C. Boisneau, A. Carpentier, F. Charrier, E. De Oliveira, J. Dublon, E. Feunteun, É. Gharnit, P. Jugé, J. Lamoureux, Y. Lepéru, A. Lizé, P. Rault, R. Roy, F. Santoul, Structures associatives agréées de la pêche loisir, N. Teichert & L.-S. Virag, 2023. GLANISPOMI : Etude globale de la prédation des migrateurs amphihalins par les silures (Silurus glanis) sur le bassin de la Loire. In: Trancart, T., E. Robin & E. Feunteun (eds).
Westrelin, S., S. Boulêtreau & F. Santoul, 2022. European catfish Silurus glanis behaviour in response to a strong summer hypoxic event in a shallow lake. Aquatic Ecology doi:https://doi.org/10.1007/s10452-022-09952-y.
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