The Effect of Temperature on the Cruising Speed of Young Sockeye and Coho Salmon

Abstract

The cruising speeds of underyearling and yearling sockeye and coho salmon were determined in a rotating annular trough, for acclimation temperatures ranging from 1° to 24 °C. Variation in swimming speed characterized the first 40 to 50 minutes; subsequently a relatively steady state was obtained.Optimum cruising speeds occurred at 15 °C. for sockeye and 20 °C. for coho. Maximum sustained levels fell mainly between 1.0 and 1.5 ft. per second (30 and 45 cm. per sec.).Exercised young coho showed improved performance over those raised in standard hatchery troughs.The significance of the relative swimming capacities of the two species, and the effect of temperature, is discussed in relation to their ecology.