Session A6: Telemetric Survey of Upstream and Downstream Migrating Species at the River Elbe, Germany

• Main Authors: Klan, Juliane, Adam, Dr. Beate
• Format: Text
• Language: unknown
• Published: ScholarWorks@UMass Amherst 2015
• Subjects: Aquaculture and Fisheries; Hydraulic Engineering; Weir; Atlantic salmon
• Online Access: https://scholarworks.umass.edu/fishpassage_conference/2015/June23/54

Abstract: The detection of movement patterns of species in rivers can be realised by acoustic telemetry. From 2012 till 2013 a survey on migrating species by means of telemetry was conducted in the river Elbe focussing on following questions: How do successful upstream migrating fish behave after swimming through a fish pass? To what extend is a direct downstream migration taking place? The investigation area is located 30 km upstream the city of Hamburg in the 400 m width headwater of the weir Geesthacht. The migration barrier is equipped with a new double slot pass at the north bank and a natural like channel (since 1996) at the south. 6 anadromous (n=161) and 10 potamodromous (n=127) species were tagged with an acoustic transmitter after passing the fish ways successfully. Additionally a group of tagged Atlantic salmon smolts (n=76) were released 8 km upstream the weir. 21 hydrophones were installed along the river banks over a section of 4 km upstream the weir to detect the movement patterns of the released specimens. Very good redetection quotes were achieved: 68% of anadromous as well as 65% of potamodromous species and 95% of salmon smolts were redetected. Several typal behaviour patterns have been observed: No matter, if the tagged fish were released at the head of the old or the new fish pass, the upstream migrating anadromous specimens tend to follow the current flow to pass the investigation area very fast and in beeline. Also the salmon smolts migrated immediately in just 4 hours throughout the headwater and pass the weir. Not even local turbulences e.g. caused by a pumped storage plant could affect this movement patterns. In contrast potamodromous fish show a remarkable unsteady cruising behaviour and just onethird continued their upstream migration along the same river bank where they had been released.