Potential Effects of Kaplan, Ossberger, and Bulb Turbines on Anadromous Fishes of the Northeast United States

Publication Date



Prepared for U.S. Department of Energy.


bulb turbines, turbines, turbine passage, Atlantic salmon, salmon, smolt, Salmo salar, juvenile, adult, American shad, shad, Alosa sapidissima, blueback herring, herring, Alosa aestivalis, striped bass, bass, morone saxatilis, steelhead, trout, mortality, guidance, delayed mortality, Kaplan turbine, Holyoke, Holyoke Dam, Massachusetts, mark-recapture, survival, recapture, impingement, Essex Dam, turbine mortality

Report number



Knapp WE;Kynard B;Gloss SP;

Publication place

Newton Corner, MA


U.S. Fish and Wildlife Service


The effects of turbine passage on anadromous fishes of the northeast United States were investigated in the field and laboratory. Kaplan, Ossberger, and bulb turbines were studied using Atlantic salmon smolts (Salmo salar), juvenile and adult American shad (Alosa sapidissima), juvenile blueback herring (Alosa aestivalis), striped bass (Morone saxatilis) and rainbow and steelhead trout (Salmo gairdneri). The effects of turbine size and electric power level on mortality were studied in the field. Laboratory investigations and other field studies focused attention on turbine-induced scale loss and its potential for sublethally affecting Atlantic salmon smolts, juvenile American shad, and blueback herring. The investigations provided valuable guidance for conducting turbine-passage studies in the future and furnished useful estimates of acute and delayed mortality. At the 17 MW Kaplan turbine at Holyoke Dam, Massachusetts, mark-recapture and radiotelemetry techniques were used to estimate acute mortality. Juvenile American shad and blueback herring experienced 63% mortality at 16.5 MW, 83% at 12.0 MW, and 83% at 5.5 MW. Laboratory experiments with blueback herring indicated an extreme sensitivity to scale loss. Only 8-10% loss of scales significantly increased mortality in test fish within 48 hours. Preliminary radiotelemetry experiments with adult American shad indicated a maximum possible mortality at five hours of about 50%. Further research is needed to establish the level of mortality with greater confidence. Similar experiments with Atlantic salmon smolts indicated 4.9% mortality for turbine-passed fish within two hours. In the laboratory, removal of 27% of the scaled area of pre-smolts caused a significant decrease in average survival of fish in fresh water. At two Ossberger Cross-Flow turbines (650 and 850 kW) at Goodyear Lake, New York, recapture studies were used to estimate acute and latent mortality. Juvenile American shad experienced 50% acute mortality passing through the larger turbine at 320-540 kW. Striped bass underwent 54% total mortality, but this estimate probably includes some additional mortality from net impingement. An empirically-derived equation based on mortality experienced by rainbow and steelhead trout predicted 24-62% mortality for Atlantic salmon smolts, depending on their size. Scale loss of smolts passed through the turbines was not significantly different from controls. In test fish that died within 48 hours, there was a significant increase (7%) in scale loss compared to controls. Experiments using two 7.8 MW bulb turbines at the Essex Dam, Massachusetts, demonstrated the potential usefulness of simplified techniques involving radiotelemetry for determining turbine mortality. Preliminary estimates of mortality after five hours for two-year-old Atlantic salmon smolts were less than 2%. Additional investigation is required to better establish the utility of the methods and estimates.