Effects of Stocking Size and Rearing Method on Muskellunge Survival in Chautauqua Lake, New York

Abstract

We examined the effects of rearing method and size at stocking on the survival of muskellunge Esox masquinongy in Chautauqua Lake, New York. Since 1961, changes in rearing methods have coincided with declining abundance of adult muskellunge. In particular, a change from pond rearing to trough rearing coincided with declining catches of adult muskellunge in pound nets. The decline was only partly reversed by changes from trough rearing to pond finishing of fingerlings. Changes in survival to age 5 from 1961 to 1996 indicated that both rearing method and stocking length significantly affected survival. Greater length at stocking resulted in higher survival rates. After accounting for length at stocking, survival was highest for pond-reared fingerlings, intermediate for pond-finished fingerlings, and lowest for trough-reared fingerlings. A modified Ricker stock–recruitment model indicated that survival of fingerlings declined over time. Increases in the adult stock of walleye Stizostedion vitrium since the 1960s may have increased predatory pressure on fingerlings and increased the importance of greater length at stocking.