HALAMEAUP
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Habitat Use by Sea Lamprey in Deep-Water Environments |
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Research
The sea lamprey is an anadromous migratory species at risk, with populations declining across much of its range, particularly in France. Current monitoring methods (fish pass counts, spawning ground surveys, and fisheries data) reveal a mismatch between the number of individuals entering estuaries and the number of spawning sites observed further upstream.
This pattern is especially pronounced in the Vilaine River basin, where lampreys appear to no longer reach historically known spawning areas. In this context, it is crucial to determine whether spawning adults reproduce in poorly surveyed deep-water habitats, or whether biotic or abiotic factors limit their reproductive success despite their arrival in estuaries. The HALAMEAUP project aims to investigate the decline of sea lamprey populations in the Vilaine River. It is structured around two complementary components: (i) a “habitat” component dedicated to high-resolution mapping of approximately 40 km of river channel (using bathymetry and sonar) in order to identify potential deep-water spawning areas; and (ii) a “telemetry” component based on tagging individuals captured during their migration at the Arzal dam. Radio transmitters are used to track individual movements, and predation tags are deployed to assess the potential role of wels catfish in the reduced reproductive success of the species in the Vilaine River.
People involved
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EVANNO Guillaume, Scientist Phone : +33 2 23 48 54 45 Email : guillaume.evanno*at*inrae.fr |
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FORGET Guillaume, Scientist Phone : +33 2 23 48 56 25 Email : guillaume.forget@inrae.fr |
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LASNE Emilien, Scientist Phone : + 33 2 23 48 54 44 Email : emilien.lasne@inrae.fr |
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MARTIGNAC François, Scientist Phone : +33 2 23 48 56 25 Email : francois.martignac@inrae.fr |
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MICHELOT Armand, Technician Phone : +33 2 23 48 52 37 Email : armand.michelot@inrae.fr |
Funding and Support
OFB