Angler harvests of muskellunge exceeds natural recruitment in most muskellunge waters in Wisconsin; consequently, populations are supplemented by hatchery propagation. This paper summarizes survival estimates from 5 egg, 6 fry and 74 fingerling stockings. Factors influencing survival were examined by comparing estimates of fall fingerling density and two indices of survival to a set of independent factors using simple correlation and stepwise regression.
Stocking fertilized muskellunge eggs on gravel and sand substrate resulted in a measurable year class of muskellunge in two of five trials, and fall fingerlings were observed from two of six fry stocking. Survival of stocked fingerlings to fall averaged 38.7% and ranged from 0.0% to 95.7%.
In multiple regression analyses of 59 fingerling stocking, a significant positive relationship was found between observed survival to fall and length at stocking. A negative relationship between fall survival and days ar large was also identified but this was expected. The geometric mean daily survival was independent of the number of days in the lake and provided a better index for examining the effects of the independent factors on fingerling survival. Mean daily survival was positively correlated with length at stocking and days at large. The fall population density of fingerlings was highly correlated with the initial stocking rates. Tests of the above model with nine later stockings found the effects of length at stocking to be variable.
This study suggested that best survival for first fall was achieved by stocking the largest fingerlings, however, similar results may have been achieved by stocking proportionately greater numbers of smaller fingerlings. There was no evidence that high stocking rates adversely affected fingerling survival.