Distribution and abundance of lampetra planen populations in the peene drainage (NE Germany) in relation to isolation and habitat conditions

Abstract

In the Ziemenbach, a third order stream of the Peene system, the habitats and density of brook lamprey (Lampetra planert) were investigated. A catalogue of habitat requirements for ammo-coetes and adults was compiled. The abundance of brook lamprey was determined by counting adults on the spawning sites and systematic sieving of the ammocoetes. Human impact is probably the reason for strong changes in the population density during the investigated years. Habitats of lampreys in European streams are endangered by channelling and river maintenance. Together with other factors, this has led to the extinction of many populations. The occurrence of L. planen in the Peene drainage is now limited to 15 tributaries, although suitable habitats have been found in 36 streams, one third of the whole drainage system. To reduce the isolation of the populations and to enable the resettlement in other streams, up to 70 weirs with fish passes have to be construct. © 1998 Taylor & Francis Group, LLC.