PNNL

Abstract

The effects of downstream passage through a novel turbine designed for fish safety, the Restoration Hydro Turbine (RHT), were studied for American eel (Anguilla rostrata) in a recirculating turbine test facility. A 55 cm diameter RHT was operated under 10 m of hydraulic head and 667 revolutions per minute. A total of 131 eel were passed through the turbine, and 43 eel were used as experimental controls. Eel length ranged from 33.9 cm to 65.5 cm. High-speed video of passage through the runner region was captured for 89% of turbine-passed eel, and injury and behavioral effects were recorded immediately before and after passage, as well as after a 48-hour hold period. A subset of 37 eel was additionally examined with X-ray imaging for internal injuries. The 48-hour survival rate for both treatment and control groups was 100%, with no major internal or external injuries present after the hold period. This result suggests that hydropower plants designed for safe through-turbine downstream fish passage could be implemented without major disruptions to eels.