"Safe Passage of American Eel Through a Novel Hydropower Turbine," by Sterling Watson, Abraham Schneider, Leon Santen, Katherine A. Deters, Robert Mueller, Brett Pflugrath, John Stephenson, and Z. Daniel Deng.
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 eels were passed through the turbine, and 43 eels were used as experimental controls (length 33.9 cm–65.5 cm). High-speed video of passage through the runner region was captured for 89% of turbine-passed eels, 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 eels 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 is a substantial improvement over eel survival rates through conventional Kaplan and Francis turbines, which may range from 40% to 95%, and suggests that hydropower turbines designed for safe downstream fish passage could be implemented without major impacts to eels.
Our installed Restoration Hydro Turbine (RHT) projects are operating reliably, and our project development pipeline continues to grow.