Density Dependence of Walleye Maturity and Fecundity in Big Crooked Lake, Wisconsin, 1997–2003

Abstract

Density is an important factor regulating age at maturity and fecundity of fish populations, so we evaluated the effect of the population density of adult walleyes Sander vitreus on age at 50% maturity and length-specific fecundity in Big Crooked Lake, Wisconsin, during 1997–2003. Abundance of adult walleyes from mark–recapture surveys ranged from 2,046 fish (3 per acre) to 4,901 fish (7 per acre). Age at 50% maturity ranged from 3.89 to 4.88 years, length of walleye sampled for fecundity ranged from 13.0 to 24.7 in, and average fecundity of a 17-in walleye ranged from 41,061 to 53,009 eggs. Age at 50% maturity increased significantly as adult walleye population density increased, whereas average fecundity of a 17-in walleye did not change significantly with density. We conclude that age at 50% maturity could be used as an indicator of population density and exploitation stress and thus could be used to set desired levels of harvest.