Scientist

Faculty of Biology
Aquatic Ecology
Universitätsstrasse 5
D-45141 Essen
Germany

Room S05T03B12
Phone: +49.201.18.33218
Fax: +49.201.18.32179
christian.schlautmann@uni-due.de

PhD thesis: The drivers of fish migration in a low mountain river, monitoring the fish lift system Baldeney

Rivers harbour a high species richness that depends on a longitudinally connected ecosystem. This is why the EU Water Framework Directive (WFD) requires fish passage for European watercourses. However, more than 1.2 million obstacles in Europe block the way of inhabitants such as fish. Some of these structures can be dismantled, but most are tied to functions such as drinking water abstraction, flood protection, power generation, recreational use, etc. To restore fish passage, fishways such as the novel Fish Lift System Baldeney (FLS) (Fischlift - Ruhrverband) are built on the Ruhr River, North Rhine-Westphalia, Germany. The weir at Lake Baldeney was the second last in the lower reaches of the Ruhr without a fish pass. Thus, as a product of highly technical engineering and nature conservation, the FLS represents an important step towards restoring fish passage in the Ruhr.

As the fish lift, which is unique in its design, represents a superior type of fish pass, it is necessary to check its functionality according to the "DWA-Merkblatt 509" and the "Handbuch Querbauwerke". From September 2023, I will be involved in this functional check, as well as the scientific investigation of the FLS, and the analysis of the abiotic drivers that motivate the fish to migrate. Methodologically, this investigation will be carried out through two year fish monitoring by means of electrofishing, video recording of migrating fish ("VAKI-Riverwatcher"), a sonar system (DIDSON), fish tagging by means of telemetry (HDX-PIT tags) and the quantification of abiotic parameters. I am working together with the Ruhrverband .

One aim is to quantitatively assess the detectability of the FLS for the fish. In addition, the ascent process is to be investigated regarding duration, possible scouring effects and the effectiveness in comparison to other fish passes. I am also interested in the abiotic drivers of migration to optimise the FLS. Overall, this will contribute to the further development of the special state-of-the-art fish pass solution. In addition, I would like to contribute to creating transferability to other locations where standard fish pass solutions are not possible or the fish lift has advantages over other fish passes. An example of this would be the weir in Kettwig on the Ruhr.