Influence of Food Web Structure and Environmental Conditions on Walleye Stocking Success in Two South Dakota Impoundments

Demand for Walleye Sander vitreus throughout North America has resulted in increased stocking efforts and management of Walleye populations. Despite annual stockings, Walleye abundance in Mina Lake, South Dakota has remained low. Previous research at Mina Lake has shown increased trophic state, large proportions of benthic invertebrates consumed by stocked Walleye, and increased abundance of Freshwater Drum Aplodinotus grunniens, a benthic insectivore. The purpose of this study was to address several objectives related to Walleye stocking success in Mina and Richmond lakes: 1) document seasonal patterns in productivity and prey abundance to explore differences in Walleye food habits and growth (Chapter 1), 2) compare growth and condition of adult Walleye in relation to their food habits and trophic position (Chapter 2), 3) compare survival and growth of stocked juvenile Walleye as related to abiotic and biotic factors (Chapter 3) , and 4) quantify growth and food habits of Freshwater Drum and compare to Walleyes in Mina Lake (Chapter 4). Productivity and prey abundance was measured monthly in 2010 and 2011. Dissolved oxygen was lower in Mina Lake and a large portion of habitat was hypoxic. Productivity was greater in Richmond Lake. Total invertebrate density was not different between lakes nor was individual taxa. Limited dissolved oxygen and productivity during the growing season may reduce growth of Walleye in Mina Lake. Walleye were sampled monthly in 2010 and 2011. Age was estimated and stomach contents examined. Mean length, condition, and proportion of taxa in Walleye diets was compared between lakes and sampling years. Condition and growth of Mina Lake Walleye was reduced due to a higher proportion of invertebrates and vegetation in diets. Survival, growth, and diet composition was measured for stocked Walleye fingerlings. Poor survival was related to low dissolved oxygen. Growth was faster in Mina Lake due to consumption of large bodied zooplankton taxa. Freshwater Drum had fast growth rates and diet overlap with Walleye was high in summer when foraging habitat was limited by hypoxia. Freshwater Drum may compete with Walleye for prey resources and available habitat in Mina Lake, thus contributing to reduced growth of Walleye.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Natural Resource Management

Year

2014

Author dc:creator

• Thul, Megan D.

Contributors dc:contributor

• Steven Chipps

• Natural Resources and Conservation

Statement dc:rights

• Copyright © 2014 Megan D. Thul. All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/579

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1579