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SEPG 2058 - Date Awarded 2002
Migratory behaviour and habitat use of anadromous river lamprey
Dr. Min-Ho Jang
Abstract
Increasing concern has been expressed regarding the conservation status of river lamprey (Lampetra fluviatilis), an anadromous lamprey species, within Europe. Commonly this species begins its upriver spawning migration in autumn and spawns in spring, yet little information is available concerning the pattern of upriver migration, influences of obstructions and the nature of over-wintering habitat. The migratory behaviour of river lamprey in the rivers Derwent and Ouse (North East England) were investigated using radio-telemetry and acoustic telemetry between November 2002 and April 2003. Adult river lampreys (94 - 170 g) were tagged externally with radio transmitters, mostly as they entered the River Derwent from the tidal River Ouse and were tracked manually and with remote receiver-loggers. Intensive radio tracking after release, close to the mouth of the Derwent, demonstrated clear nocturnal behaviour, associated with variable upstream migration rates (0.2 - 11.4 km during the first night after release). The average upstream migration speed over ground in the period November 2002 to January 2003, of fish tagged in the lower Derwent, was 1.47 ± 0.57 km/day (n = 13), with fish moving up to 44.7 km upstream. Many radiotagged fish congregated below weirs where they remained until spawning or tags stopped functioning.
Full report: SEPG2058
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