Protection and Guidance of Downstream Moving Fish with Electrified Horizontal Bar Rack Bypass Systems

Horizontal bar rack bypass systems (HBR-BS) are characterized by a horizontal (HBR) with narrow clear spacing of 10–20 mm and an adjacent (BS) to efficiently protect guide downstream moving fish at water intakes. The small may lead operational challenges, such as clogging high head losses. This study investigated whether combining HBR low-voltage electric field (e-HBR) allows one increase the while maintaining standard protection guidance efficiency. To this end, HBR-BS 20 e-HBR-BS 51 were tested spirlin (Alburnoides bipunctatus) European eel (Anguilla anguilla) in laboratory flume. racks electrified 38 V pulsed direct current. efficiency e-HBR was 96% for 86% eels, which similar results those mm. Some eels passed through e-HBR, but only when they parallel rack. Fish injuries variable severeness due electrification observed. highlight potential hybrid barriers fish. However, electricity occur; reporting applied voltage, electrode geometry, resulting strength pulse pattern setup is necessary ensure comparability among studies avoid injuries.