When fish ecology meets art

Science can be so beautiful: Robert Naudascher's scientific observation shows the movement of a juvenile river trout in a laboratory test setup. The scene was filmed from below through the glass bottom of a hydraulic flume. The d-shaped cylinders create flow shadows similar to stones in a natural riverine habitat. The colors encode time – light blue refers to earlier movements, dark blue to later movements.

This kind of experimental setup can be used to quantitatively assess trout movement patterns, involving information such as tail-beat frequency, swimming speed, the orientation of a fish and the preferred location in the flow field. To derive these quantities from the video recording, special image processing methods and tracking software is deployed – a core competence of the Stocker Lab.

Anthropogenic impacts on river habitat

The findings are of great interest as they shed light on how fish react to changing currents or water temperatures and what kind of fluctuations can be problematic. Unnatural flow and temperature fluctuations occur, for example, in river courses downstream of storage hydropower plants. To what extent these fluctuations influence the behavior and survival of fish is still largely unknown.

Naudascher's clip is part of a video installation by the artist duo Badel/Sarbach, currently on display at ART SAFIENTAL. Their installation, entitled «Lost Water and Found Stairs», focuses on a poetic-philosophical approach to the changing habitat of rivers, especially from the perspective of fish that are struggling with increasingly fragmented habitats. external page ART SAFIENTAL takes place every two years and still runs until 23 October 2022.

The PhD project is jointly supervised by the Stocker Lab and the Laboratory of Hydraulics, Hydrology and Glaciology (VAW).