Although few studies have been conducted to directly quantify ichthyoplanktonmortality at hydroelectric installations, there is a considerable body of literature on examinationsof the various stresses (i.e., pressure changes, blade contact, shear) that could affect turbineentrainedeggs and larvae. A review of these studies suggests that turbine-passage mortality ofearly life stages of fish normally would be relatively low at the low-head, propeller-type turbineinstallations (e.g., bulb or STRAFLO turbines), for which relevant design information is available.The shear forces and pressure changes in low-head bulb turbines are unlikely to causeichthyoplankton mortality. Probability of contact with turbine blades is related to size of the fish;less than 5% of entrained ichthyoplankton would be affected. Potential additional sources ofmortality related to the design and operation of hydroelectric facilities, and thus mitigable, includewithdrawal of deep water and cavitations.