Protecting eels at water intakes
Eel protection measures
A wealth of experience in the development of eel protection measures.
In 2016 THA Aquatic was commissioned by Fish Guidance Systems Ltd (FGS) to investigate the efficiency of an experimental strobe lighting system at eliciting an avoidance response in endangered European eels, Anguilla anguilla, to deter them from water abstraction intakes.
Trials were undertaken at the state-of-the-art aquarium facilities at Sparsholt College’s National Aquatic Training Centre.
A specially designed oval tank was created and split into two halves, housing a light and dark side. The FGS strobe systems were fitted to either side of the tank and could be operated independently.
At the start of each experiment a single silver eel of between 379-765mm length was released into the tank and allowed to acclimate. After a designated period the strobe was activated in the side of the tank and the eel’s reaction recorded by infrared camera.
Eels exposed to the strobe lighting spent more time in the dark side of the tank when compared to the control group, not exposed to the strobe. Of the 56 eels that were exposed, 84% displayed an immediate avoidance response when switched on. A further 16% showed a delayed reaction.
The next stage in the development process is to perform field trials to record the effects in the natural environment.
If effective,the FGS Strobe Lighting System could provide an alternative to physical barriers and reduce Anguilla anguilla mortality caused by water abstraction.