Life history traits and timing of elvers moving over a River Meuse dam after recent glass eel restocking

Abundance; Catch periodicity; Fish species assemblage; Glass eels; Growth rate; Large deep riverine ecosystems; Restocking; Ecology, Evolution, Behavior and Systematics; Ecology; Aquatic Science; Animal Science and Zoology

Abstract :

[en] This study describes for the first time some aspects of the life history traits and movement behaviour of young eels during the first year following their capture on the French Atlantic coasts that were released as glass eels into a large river with a vast catchment area. The restocked individuals have small size, exhibit discrete, cryptic, and benthic life habits, and have nocturnal activity. These make capturing individuals and studying this stage very challenging. Taking advantage of its positive thigmotactic behaviour, we used a fishway adapted for eels to collect samples using eel traps and trap pools lined with freshwater mussel shells. Results revealed that the restocked eels’ abundance has positively impacted the eel local stock, growth rate was good, catch periodicity followed that of older eel individuals, and composition of the associated fish species was indicative of the fish fauna that ascends the River Meuse through this fishway. These findings would open prospects for restocking using glass eels as a viable strategy to boost declining local stocks and, probably in the long term, increase the future escapement rate to the sea of silver eel spawners from the catchment, but the question of survival in large rivers still needs more research.

Research Center/Unit :

FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège
AFFISH-RC - Applied and Fundamental FISH Research Center - ULiège

Disciplines :

Environmental sciences & ecology

Author, co-author :

Matondo, Billy Nzau ; Laboratory of Fish Demography and Hydroecology, Management of Aquatic Resources and Aquaculture Unit, Freshwater and Oceanic science Unit of Research-FOCUS, University of Liège, Liège, Belgium

Ovidio, Michaël ; Université de Liège - ULiège > Freshwater and OCeanic science Unit of reSearch (FOCUS)

Language :

English

Title :

Life history traits and timing of elvers moving over a River Meuse dam after recent glass eel restocking

Publication date :

August 2026

Journal title :

Regional Studies in Marine Science

eISSN :

2352-4855

Publisher :

Elsevier B.V.

Volume :

101

Pages :

105285

Peer reviewed :

Peer reviewed

Additional URL :

https://api.elsevier.com/content/article/PII:S2352485526005402?httpAccept=text/xml

Funders :

EMFF - European Maritime and Fisheries Fund

Funding text :

This research was supported by the European Maritime Affairs and Fisheries Fund and the Wallonia Public Service Grant Project # A161\u20132311\u2013006 represented by Rachel Sundar Raj, Micka\u00EBl Dubois and Beno\u00EEt Thirionet. We would like to thank the Editor-in-chief, the Associate Editor Dr. Alberto Teodorico Correia and the two anonymous reviewers for their valuable comments on the manuscript, and the Walloon Public Service for Agriculture, Natural Resources and Environment in the Environment and Water Department of the Surface Water Directorate for providing the temperature and flow data.

Available on ORBi :

since 30 July 2026

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