The Efficiency of Fish Ladders

For years, the number of fish passage solutions in Europe has increased rapidly. But do they all really meet their purpose? Field studies often reveal surprising and unexpected behaviors of fish. With our telemetry and imaging techniques, we can accurately determine the attractiveness, efficiency and functionality of fish passes for various fish species.

Testing Fish Ladders & Fish Passes

Some pictures from our efficiency validation studies:

Free mobility of fish: The Ecological Continuity

The Water Framework Directive (DCE 2000/60 EC) has given top priority to the restoration of the ecological continuity of European watercourses and still requires many further developments today. The construction of fish passes enables fish to recolonize previously isolated streams and rivers.
Although many hydraulic engineering companies can nowadays perform such realisations, fish monitoring programs are necessary to validate the functionality of fish passes and, if needed, to provide site-specific information for their improvement.

In order to determine the efficiency of a fish pass, the attractiveness of its entrance and exit must be known. The latter can be deduced from the entry and exit rates of fish passes (More information here), which we can determine with our telemetric techniques.