Flashlight keeps eels away from hydroelectric power station
As stimulating as flashing lights and loud beats may be for humans, they can be far more frightening for animals. We investigated whether this also applies to eels in the Albert Canal, specifically at the hydropower station in Hasselt.
From November 2021 to April 2022, we studied the behaviour of 30 eels, which were tagged and tracked using acoustic telemetry, near strobe lights installed at the inlet of the hydroelectric power station. Previous research has shown that approximately 12% of eels migrating through the Albert Canal toward the sea enter the inlet in the absence of strobe lighting. Of those that are drawn into the hydropower station, around 8 % do not survive and around 9 % suffer serious injuries.
The aim of our study was to determine whether the eels would avoid the strobe lights and thus stay out of the intake zone leading to the power station. Thirteen of the 30 tagged eels approached the lights—some only once, others multiple times. With one exception out of 31 total approaches, the eels immediately swam away from the flashing light. As a result, none of the 29 eels whose movements we could track completely, entered the intake channel.
Based on these observations, we conclude that the number of eels entering the hydropower channel was reduced by 12% due to the presence of strobe lights. Strobe lighting thus appears to be an effective deterrent for migrating eels based on our study.
However, for the eels to reach the sea quickly and safely, they must find an alternative route—something that is particularly challenging in a busy shipping canal. For this reason, we are now investigating with De Vlaamse Waterweg nv whether and how other hydropower stations and lock complexes along the Albert Canal should be equipped with similar strobe light deterrent systems. Our goal is to help the critically endangered European eel migrate to the sea more safely and efficiently.
Ine Pauwels, Sarah Broos & Johan Coeck