Experiments to deflect young spring salmon during their night-time migration by means of a beam of light and/or a "wall" of bubbles were conducted in a canal near Courteney, B.C. Under natural conditions (by the use of hoop nets) no significant difference existed in the respective catches of spring salmon underyearlings moving downstream. However, a significant difference was obtained when a narrow beam of light was directed into the water at a downstream angle in front of one net. A reduction to about 1/3 the expected catch resulted with either continuous or flashing light. The "wall" of bubbles, in a similar position, did not reduce the catch. Cut-throat trout fry and hatchery-reared Kamloops trout fingerlings were not deflected under these conditions.