Verplaatsen van de beekprik binnen de Keersop

The translocation of the Brook lamprey within the Keersop stream The stream the Keersop (province Noord-Brabant) is given a more natural course by creating several new meanders. The Brook lamprey (Lampetra planeri) occurs in the stream and these heavily protected fishes had to be translocated from parts of the stream that were to be filled up to other parts. Electrofishery is a poor method for collecting Brook lampreys and for some parts of the stream only a dip net was used. Some parts of the stream became completely vegetated in one year, due to damming. The water vegetation was too dense for the nets and instead the soil was dredged and placed on the stream banks after which the fishes were collected by hand. These densely vegetated stream parts were surprisingly rich in lamprey individuals and this provides new insights in the preferred habitat and movements of this species. We collected 1336 individuals from the 1.3 km stream stretches that were to be filled up. This number suggests that the 13 km long Keersop stream might harbour many thousands of Brook lampreys.