Michigan Department of Natural Resources
Fisheries Research Report No.1814, 1974
Effects Of Artificial Destratification On Rainbow Trout (Salmo gairdneri Richardson) Depth
Distribution and Growth in a Northern Michigan Lake
Arlo W. Fast and Lee W. Miller
Abstract.-Rainbow trout (Salmo gairdneri Richardson) showed no dramatic response to the artificial destratification of a small, non-productive Michigan lake. Relative to a summer of normal stratification, their depth distributions were not greatly altered, growth rates of one-year olds were not significantly different, nor did any obvious increase in mortality occur during destratification. Oxygen concentrations were never limiting to the trout either before or during mixing; however, the minimum and average water temperatures were greatly increased by destratification. Minimum temperature increased from less than 8 C to over 23 C during destratification, but temperatures remained sublethal.