Juvenile alewife, conducted with Kleinschmidt Associates, Fall 2021

Study Overview
Turbine:
.55 m (1.8 ft) diameter RHT at 7 m (23 ft) head, 541 rpm
Quantity:
3 treatment and 2 control groups, (484 turbine-passed fish)
Species:
Juvenile alewife, 87-132 mm (3-5 in) length
Results:
99-100% immediate and 48h survival of turbine-passed fish

Alosines (shad and river herrings) are an important and highly sensitive group of migratory fish species affected by hydropower and river fragmentation in eastern North America. In September of 2021, Natel evaluated juvenile alewife (Alosa pseudoharengus) passage survival through a .55 m (1.8 ft) RHT at Freedom Falls, Maine, with assistance from Kleinschmidt Associates.

We collected locally downstream migrating juveniles, passed them through the turbine in groups, and collected them at the outlet with a specialized trap. We captured turbine passage with high-speed video and compared turbine passage survival rates with control group survival. This work is summarized in a manuscript that is currently under publication review.