Differences in Population Characteristics and Modeled Response to Harvest Regulations in Reestablished Appalachian Walleye Populations

Abstract

Historically, the Monongahela, Tygart, and Cheat River watersheds in West Virginia were impaired by acidification from acid mine drainage and Walleye Sander vitreus were extirpated from these watersheds by the 1940s. Walleye were reestablished after water quality improvements following passage of environmental legislation and subsequent reintroduction efforts. We compared population characteristics, with emphasis on growth, of Walleye and used modeling to predict the potential effects of harvest regulations in the Monongahela River and two main-stem reservoirs in the Cheat River and Tygart River watersheds. Statistical comparisons of von Bertalanffy growth curves and relative growth indices indicated that Walleye growth significantly differed across all water bodies. Relative growth index results suggested that Walleye growth was above average in Cheat Lake, average in the Monongahela River, and below average in Tygart Lake relative to other North American populations. Growth was negatively correlated with Walleye relative abundance and positively correlated with estimates of productivity (total phosphorus, chlorophyll a). Walleye diets significantly differed across all water bodies, with diets dominated by Yellow Perch Perca flavescens and Gizzard Shad Dorosoma cepedianum in Cheat Lake, where growth was fastest. Population modeling suggested that effects of exploitation on yield, spawning potential, and size structure were similar under regulations of no length limit and a minimum length limit (381 mm). Models suggested that removing length limits in Tygart Lake could increase angler harvest opportunities and pose minimal threat to the fishery. Models suggested that a protected slot limit could provide increased protection to the spawning potential of Cheat Lake and the Monongahela River populations. Additionally, models predicted that a protected slot limit could increase the number of large (>630-mm) Walleye in these waters. Our findings demonstrate the different characteristics that Walleye populations can develop after reestablishment based on abiotic and biotic conditions and the need for watershed-specific management.

Special Section Overview: Effects of Ecosystem Change on North American Percid Populations

“…2022, this special section; Smith et al. 2022, this special section). Evolving sociopolitical factors, such as stakeholder expectations and values, harvest and usage demographics, and laws governing management of sometimes shared recreational, tribal, and/or commercial fisheries, have impacted and continue to have ramifications for percid management (e.g., Sullivan 2003; Mrnak et al.…”

“…Historical anthropogenic habitat degradation and subsequent remediation efforts have resulted in changes in water quality in many freshwater ecosystems, with implications for percid populations and the sampling methods used to monitor population status (Hayward and Margraf 1987;Stapanian et al 2009;Bacheler et al 2011;Gibson-Reinemer et al 2017;Hansen et al 2019;Holbrook et al 2022, this special section). In addition, warming water temperatures, changing water quality, and future climate projections have influenced and may continue to influence freshwater fish communities through alterations in physical habitat availability (Magnuson et al 1990;Ferguson 2004;Dippold et al 2020;Blackwell et al 2022, this special section;Skolte et al 2022, this special section;Smith et al 2022, this special section). Evolving sociopolitical factors, such as stakeholder expectations and values, harvest and usage demographics, and laws governing management of sometimes shared recreational, tribal, and/or commercial fisheries, have impacted and continue to have ramifications for percid management (e.g., Sullivan 2003;Mrnak et al 2018;Tingley et al 2019;Kozich et al 2020;Clapp et al 2021).…”

“…2022), and historically similar ecosystems (productivity, latitude) do not appear to respond equally to landscape-level changes (e.g., warming water temperatures; Nate et al 2000;Hansen et al 2015a;Honsey et al 2020). Additionally, while percid populations are declining in some regions, they have increased in other locations, such as the prairie pothole lakes of North Dakota and South Dakota (Blackwell et al 2022), and they have recovered from near or total extirpation in Saginaw Bay of Lake Huron (Fielder and Baker 2019) and several West Virginia rivers that were formerly degraded by mining acidification (Smith et al 2022).…”

“…2022), and they have recovered from near or total extirpation in Saginaw Bay of Lake Huron (Fielder and Baker 2019) and several West Virginia rivers that were formerly degraded by mining acidification (Smith et al. 2022).…”