Overwinter Survival of Wild Fingerling Brook Trout in Lawrence Creek, Wisconsin

Publisher Website
Google Scholar
Abstract
Overwinter survival of brook trout (Salvelinus fontinalis) from the 9-month-old fingerling stage to the 16-month-old yearling stage varied from 35 to 73% during 11 successive winters (1954–65). Mean survival through these first winters of life was 54%.Survival appeared to be independent of fingerling density most winters, and especially when September densities were less than 2200/km, as they were during 7 of 11 years. Overwinter survival tended to increase with an increase in mean length of fingerling stocks (r = 0.83++) and with an increase in winter water temperatures. Intraspecific predation did not appear to be a critical mortality factor. The survival advantage of increased fingerling size was probably related to increased physiological resistance to temperature-associated stresses rather than reduced vulnerability to predation.