Understanding and Estimating Silver Eel Turbine Survival.

Amaral, Steve, Alden Research Laboratory LLC

Downstream passage of silver eels at hydropower dams has been the focus of considerable research with respect to injury and mortality suffered during turbine passage and the development of technologies and approaches for reducing turbine entrainment. Not surprisingly, unique behaviors, morphology, and physical attributes that are specific to silver eels have separated them from other species when it comes to estimating turbine survival and developing effective fish passage facilities. This presentation will explore what has been learned from lab and field evaluations of silver eel turbine passage and discuss desktop models for estimating turbine survival. This will include examination of the effects of turbine type and various design parameters on eel survival rates, as well as why theoretical blade strike probability and mortality models used for other fish species (e.g., salmonids, clupeids, and various freshwater fishes) are not applicable to silver eels. The use of appropriate turbine survival models is important for understanding the impacts of hydropower projects on catadromous eel populations.