Swimming speed of fall Chinook salmon (Oncorhynchus tshawytscha) fry
chinook, salmon, swimming, swimming ability, stamina, water velocity, swimming performance
Journal or Book Title
Transactions of the American Fisheries Society
Tests to determine the swimming ability of fall Chinook salmon fry were conducted in astamina tunnel located at the Salmon Cultural Laboratory, Longview, Washington. Fish weresubjected to water velocities of 0.6, 0.7, 0.8, and 0.9 ft/sec for periods of 3, 6, and 9 min. Thenumber of fish impinged on a screen placed across the downstream end of the stamina tunnelwas noted for each test. The number of fish free of the screen and still swimming at the end of thetest period was used as the measure of swimming ability. The smallest group tested, fry 33.0 to34.9 mm in length, had visible yolk sacs. Ninety-eight percent of these fish were capable ofcoping with velocities of 0.6 ft/sec for at least 3 min. Only 88% and 72% of these small fish couldcope with increased velocities of 0.7 and 0.8 ft/sec. Larger fry performed better; however, a slumpin performance in fish 37.0 to 38.9 mm in length was noted. Changes of 0.05 ft/sec causedmeasurable changes in swimming performance, and the number of fish impinged increased withexposure time.