Comparisons of Walleye Fecundity Before, During, and After Rehabilitation of the Red Lakes Fishery

Abstract

Abstract The Red Lakes, Minnesota supported a substantial Walleye Sander vitreus fishery from the early to mid-20th century but experienced a major crash in the late 1990s. The population has since rebounded after a successful interagency recovery program and now supports valuable commercial and recreational fisheries. The variation in population densities associated with the collapse and subsequent recovery in the Red Lakes Walleye population provides a rare opportunity to study potential changes in relative fecundity (eggs/kg of body mass) under varying rates of exploitation: overexploited (1989 data), recovering (2004 data), and recovered (2017 data). We collected female Walleye in spring of 1989 (n = 30) from the Blackduck and Tamarac rivers and in spring of 2004 (n = 30) and 2017 (n = 30) from the Tamarac River. Results indicate that relative fecundity was significantly lower in 2017 (50,768, SD = 10,266) than in 1989 (58,216, SD = 6,211) and 2004 (61,964, SD = 7,472). We hypothesize that differences in relative fecundity among fishery states were due to differences in Walleye population abundances caused by varying exploitation rates in the years leading up to fecundity estimates.