Chronic Stress Induced by Inland Navigation on Native and Alien Fish Species in the River Waal

Level: Master
Start: Anytime
Project duration: 6 months
Project form: laboratory work, data analysis, report writing
Supervision: Natasha Flores, Juriaan Metz and Frank Collas
Mail addresses:,

Description of the project:

In heavily modified rivers inland navigation is a chronic stressor with many direct and indirect effects on ecosystems. Direct effects include producing wave action, emitting noise, and the resuspension of sediments, among others. These effects have the potential of producing chronic stress on fish and shipping intensity is expected to increase in the future. The pilot project of the longitudinal training dams (LTDs) in the Waal have shore channels sheltered from the effects of inland navigation that serve as refugia for fish. A method for assessing chronic stress on fish is the testing of stress hormone cortisol levels in their scales, where it accumulates through their lives.

The use of fish scales collected in 2021 during fish monitoring campaigns in the LTD shore channels and traditional groyne fields could help to elucidate the benefits of these novel ecosystem-based training structures. Hence, with this project we aim to assess the concentrations of cortisol in the fish caught at the two different training measures. Further we aim to assess if the native species are more sensitive to disturbances than the alien fish species.