The effects of a wide range of turbidity and turbulence levels on the short-term survival of Mysis relicta under laboratory conditions were examined. The levels of turbulence and turbidity used bracket the conditions which Mysis relicta may be expected to encounter in one area of Twin Lakes, Colorado during the operation of a pumped storage power plant. Turbulence caused a highly significant increase in mortality; mortality was not significantly affected by the three levels of turbidity tested (0, 735–779, and 1,470–1,558 American Public Health Association turbidity units of glacial flour sediments) nor by the interaction of turbidity and tubulence. Mortality of Mysis relicta subjected to turbulence increased significantly over the 8-day experiment. Exhaustion from inability to feed and from continuous swimming during turbulent periods is suggested as the possible cause of increased mortality observed over time during the experiment.