Ethohydraulic experiments on the fish protection potential of the hybrid system FishProtector at hydropower plants

The FishProtector, an Electric Flexible Fish Fence is investigated in ethohydraulic experiments. protection potential tested using outdoor, experimental channel. To find optimum parameter settings, cable clearance, approach flow angle, and the size of electric field vary within predefined limits. Due to combination both, physical barrier (tensioned steel cables) behavioral (pulsed low voltage range), fish no longer depends solely on clearance. Generally, all setups with combined barriers show mean rates higher than 97%. Cable clearances 60 mm (largest this study) same as 30 mm, each field. setup was a non-scaled section-model runoff river power plant. experiments were performed wild PIT-tagged brown trout (Salmo trutta), rainbow (Oncorhynchus mykiss), grayling (Thymallus thymallus), chub (Squalius cephalus). Measured body lengths between 100 285 mm. FishProtector wide moderate fields both significantly improves rate, showing significant for operating hydropower plants.