Walleye Spawning Date Varies with Age

Fish stock stability has been related to the presence of multiple ages of spawning females. Female Walleye (Sander vitreus) from various age classes are known to produce eggs of differing quality. This study assesses whether there also exists a difference in the timing of egg deposition related to age, which may confer stock stability. The Lake Winnipeg commercial Walleye fishery is opened each spring based on 80% of females caught in gillnets at Hecla Bar being spawned out. In 2011, 993 females were killed in gillnets ranging from 1.5” to 6”. Seven age classes from five to eleven years old displayed a six day range in the median day of arrival at Hecla Bar; younger fish arriving first, and arrival of older fish trending 0.86 days later for every year of age (r² = 0.67). This relationship will be tested again in 2012 and the results added to the presentation.