Brett, J.R., and D. MacKinnon. 1953. Preliminary experiments using lights and bubbles to deflect migrating young spring salmon. Journal of the Fisheries Research Board of Canada. 10:548-559.

Region: Canada Species: Spring-run chum, coho, pink, rainbow and steelhead trout

Study Objectives: Exploring mechanisms to alter the downstream migratory path of young salmon for sage passage around destructive barriers (i.e. turbines).

Study Methods: Juvenile salmon catch in one of two hoop nets set in each half of a concrete and brick-lined power-intake canal was used to indicate if a bubble curtain deployed at a 40 degree angle in a 3 ft/sec velocity current could successfully deflect the migratory path of juvenile spring salmon.

Results: Under natural conditions, no significant differences existed in the respective catches. Juveniles. A significant difference was obtained, however, when a narrow beam of light was directed into the water in front of one net. Increased deflection occurred on rainy or overcast nights with maximum deflection occurring with flashing light. The average success of deflection with spring migrants can be expressed as two fish deflected for every three fish approaching the net. Cut-throat trout fry and hatchery-reared trout fingerlings were not deflected under these conditions.