Fish passage survival/injury through the Hydro Green Energy hydrokinetic turbine at the Mississippi Lock and Dam No. 2 Project

A controlled fish survival and injury study was completed in 2009 at the first commercial hydrokinetic turbine installed in the U.S.  The turbine was developed and installed by Hydro Green Energy ; survival and injury were assessed using the HI-Z Turb’ N Tag direct recapture technique.  Direct survival and injury estimates were obtained on small fish (115-235 mm TL) and large fish (388-710 mm TL).  Species tested included bluegill, yellow perch, channel catfish, bigmouth buffalo, and smallmouth buffalo.  Treatment fish were released directly upstream of the HGE turbine and control fish were released downstream of the unit.  Fish were recaptured, examined for injuries, and then held for 48 h to evaluate post-passage effects. Three hundred small fish and 302 large fish were released and nearly all were recaptured (98% small fish and 99.5% big fish).  The estimated survival rates were ≥ 99% for both size groups.  All estimates were within ± 5%, 90% of the time.  None of the examined fish displayed any visible injuries.  The low water velocities (5-10 ft/sec), low number of blades (3), slow blade rotation (21 rpm) lack of pinch points, and zero operating head all contributed to the fish friendliness of the HGE turbine.