Wildlife

Wild River Lamprey Migration Welfare

River lampreys are ancient jawless fish whose upstream migration to spawn is increasingly obstructed by weirs and water abstraction.

Key Facts

Lampreys migrate upstream to spawn in clean gravel beds in spring
Weirs and culverts block lamprey migration causing population fragmentation
Lamprey-specific passes have been developed as they require different design to fish ladders
River lampreys are a Species of Conservation Concern in the UK
Larvae spend several years buried in river sediment before metamorphosing and migrating

Welfare Considerations

Lampreys unable to reach spawning grounds expend exhausting energy attempting to bypass barriers before dying without reproducing. The welfare of migrating lampreys is directly affected by the number and passability of obstacles in their migration route. River passage improvement benefits lamprey welfare and river biodiversity.

What You Can Do

Support river restoration removing obsolete weirs and improving fish passage
Advocate for lamprey-specific pass design in river barrier assessment
Join river monitoring programmes recording lamprey presence and migration