Black Crappie Influences on Walleye Natural Recruitment in Northern Wisconsin Lakes

Abstract

Walleye Sander vitreus natural recruitment has declined in northern Wisconsin lakes over time. Several factors have been implicated to explain Walleye natural recruitment declines in Wisconsin, including climate change, Largemouth Bass Micropterus salmoides interactions, less desirable fish communities, production overharvest, and depensatory effects on recruit survival. Previous research in other systems has suggested that White Crappie Pomoxis annularis negatively influence Walleye recruitment, but interactions between Walleye recruitment and Black Crappie Pomoxis nigromaculatus have not been examined. We evaluated trends between Black Crappie and age‐0 Walleye relative abundance (catch per effort [CPE]) collected in northern Wisconsin during 1991–2017. Specifically, we tested for (1) trends in age‐0 Walleye and Black Crappie CPE over time, (2) a relationship between age‐0 Walleye and Black Crappie CPE, and (3) the influence of several abiotic and biotic covariates (including Black Crappie CPE) on age‐0 Walleye recruitment. Age‐0 Walleye CPE declined and Black Crappie CPE increased significantly during 1991–2017. Within lakes, the relationship between age‐0 Walleye and Black Crappie CPE showed a threshold effect such that age‐0 Walleye CPE was always low when Black Crappie CPE was high. Of the abiotic and biotic covariates tested to explain variability in the age‐0 Walleye and Black Crappie CPE relationship, only Black Crappie CPE was significant. Our results suggest that Black Crappie may negatively influence Walleye natural recruitment; however, we caution that our findings only reveal a pattern and not a mechanistic explanation for negative interactions between the species. Additional research is needed to test for mechanistic interactions between Walleye and Black Crappie and to inform comanagement of these species.

Synthesizing Professional Opinion and Published Science to Build a Conceptual Model of Walleye Recruitment

“…2003b; Broda et al. 2022) except when abiotic drivers are catastrophic (e.g., storms; Roseman et al. 1999).…”

Fisheries Volume 48 Number 4 April 2023

“…Abiotic conditions appear to mostly indirectly affect mortality, while biotic drivers may have direct, overriding effects on recruitment during the fi rst year of life (Quist et al 2003b ;Broda et al 2022 ) except when abiotic drivers are catastrophic (e.g., storms; Roseman et al 1999 ). The differences between biotic and abiotic drivers extended to our comparison between the literature and professional opinions, where professional opinion highlighted the importance of biotic interactions, despite the literature emphasizing abiotic (physical) variables.…”

“…As a result, Walleye have one of the most robust monitoring records of any North American freshwater species (e.g., Bozek et al 2011 ). Furthermore, Walleye recruitment varies across space and through time (Haglund et al 2016 ;Rudstam et al 2016 ;Honsey et al 2020 ;May et al 2020 ;Feiner et al 2022 ), making it an ideal species to explore the mechanisms that govern recruitment, as well as whether those mechanisms vary with environmental context. Walleye are distributed across North America with native populations concentrated in the Midwestern United States and Ontario, Canada, with introduced populations across the continent.…”

“…However, exceptions were identifi ed, such as variation in the infl uence of nonnative Rainbow Smelt Osmerus mordax on Walleye recruitment (i.e., Rainbow Smelt could hamper recruitment by preying on larval Walleye, but bolster recruitment by serving as prey for juveniles; Mercado-Silva et al 2007 ;Mrnak et al 2022 ). Additionally, spring thermal conditions (e.g., warming rate, growing degree-days; Hansen et al 1998 ;Beard et al 2003 ;Shaw et al 2018 ;Honsey et al 2020 ;Feiner et al 2022 ) and habitat quality (defi ned here as availability, substrate size, and macrophyte density; e.g., Hoyle et al 2012 ; see Supplement for details) were relatively consistent in their positive relationship with Walleye recruitment among recruitment studies. In some cases, the directional effect varied based on Walleye life stage.…”

Density‐dependent and environmental influences on juvenile walleye Sander vitreus (Mitchill) survivorship in northern Wisconsin lakes

“…These results support Sass, Feiner, et al (2021) in that many walleye populations exhibited elevated juvenile mortality at low age-0 CPE. Biotic drivers of depensatory recruitment dynamics in walleye are unclear, although increased abundance of largemouth bass and other centrarchid species has been implicated in walleye natural recruitment declines with cultivation or depensation invoked as a mechanism (Broda et al, 2022;Hansen et al, 2015Hansen et al, , 2017Hansen et al, , 2018Rypel et al, 2016;Sass, Feiner, et al, 2021;Walters & Kitchell, 2001). In the absence of intervention (e.g.…”