Open Access. Powered by Scholars. Published by Universities.®

Laboratory and Basic Science Research Commons™

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Laboratory and Basic Science Research

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser May 2026

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …


Emerald Bowfin Amia Ocellicauda Ecology In Three Minnesota Lakes: Abundance, Age Analysis, Diet Composition, And Stable Isotope Food Web, Griffin Blegen Apr 2026

Emerald Bowfin Amia Ocellicauda Ecology In Three Minnesota Lakes: Abundance, Age Analysis, Diet Composition, And Stable Isotope Food Web, Griffin Blegen

Biology Graduate Theses

The Emerald Bowfin Amia ocellicauda is a predatory fish species native to Minnesota that has often been discriminated against. This research expands ecological knowledge of Bowfin in Minnesota and provides population data to guide future management. Bowfin were sampled in the spring of 2024 and 2025 and a multi-census mark–recapture model was used to estimate abundance in three lakes. Estimated populations were 196 individuals in Little Toad Lake (95% CI: 116, 242) or 4.4 fish/littoral ha (95% CI: 2.7,5.7), 657 in Lake Sarah (95% CI: 436, 1014) or 4.2 fish/littoral ha (95% CI: 3.0, 6.7), and 612 in Gun Lake …


Trophic Structure And Mercury Bioaccumulation In Walleye And Yellow Perch In The Upper And Lower Red Lake Basins, Marissa Pribyl Mar 2026

Trophic Structure And Mercury Bioaccumulation In Walleye And Yellow Perch In The Upper And Lower Red Lake Basins, Marissa Pribyl

Biology Graduate Theses

Mercury is a persistent global contaminant that biomagnifies through aquatic food webs, with dietary and environmental factors serving as the primary drivers of accumulation in fishes. Trophic structure and methylmercury dynamics in Walleye (ogaa; Sander vitreus) and Yellow Perch (asaawens; Perca flavescens) were investigated in the Upper and Lower Red Lake basins in Red Lake, Minnesota, during 2024-2025. Diets of Walleye and Yellow Perch were assessed through stomach dissections, and tissue samples from both species were analyzed for total mercury concentrations. Additional analyses included shiners (gigoozens; Notropis spp., Hudsonius spp.) along with a variety of freshwater fish and …


Size Of Age-0 Sander Vitreus Pre And Post Dreissena Polymorpha Infestation On Brainerd And Bemidji Area Lakes, Quady Bernu Jan 2025

Size Of Age-0 Sander Vitreus Pre And Post Dreissena Polymorpha Infestation On Brainerd And Bemidji Area Lakes, Quady Bernu

Journal of Earth and Life Science

Walleye Sander vitreus is the Minnesota state fish and a vital predator fish in lake ecology. Zebra mussels, Dreissena polymorpha were first found in Minnesota inland lakes in the 1980’s. These mussels have had huge impacts on water clarity as well as phytoplankton and zooplankton population levels which affect how age-0 fish feed, especially a low light feeding predator fish like walleye. A study took place on age-0 walleye size and it supported the conclusion that age-0 walleye were negatively impacted by zebra mussels in Minnesota’s large lakes. The goals of this study were to determine how the size of …


Effect Of Walleye Fry Stocking On Future Gillnet Cpue, Alexander Barker Jan 2024

Effect Of Walleye Fry Stocking On Future Gillnet Cpue, Alexander Barker

Journal of Earth and Life Science

Walleye Sanders vitreus for many states, is a key attractant of anglers from around North America. Due to immense popularity, management efforts have been conducted to maintain Walleye populations, especially in the form of stocking. The purpose of this study is to analyze the effect of Walleye fry stocking on gillnet catch per unit effort (CPUE). A total of 90 lakes were analyzed for this study within three defined regions of Minnesota, 30 from each region. The regions chosen for this study are the Minnesota Department of Natural Resources northern pike Esox lucius regulation regions which consist of the Southern, …


Relationship Between Northern Pike And Walleye Cpue In Minnesota Lakes, Simon Oslund Jan 2024

Relationship Between Northern Pike And Walleye Cpue In Minnesota Lakes, Simon Oslund

Journal of Earth and Life Science

Northern pike Esox lucius and walleye Sander vitreus are both top predators in freshwater systems. Due to their predatorial nature, high populations of one species can prohibit populations of the other species from thriving, specifically northern pike foraging on walleye. This information is tracked by the Minnesota Department of Natural Resources through catch per unit effort (CPUE). CPUE data was gathered for all lakes in Beltrami County, Minnesota, and a regression analysis was done to test for a relationship between pike and walleye. It was found that the relationship between northern pike and walleye CPUE was significant (P = 0.02). …


Analysis Of Hematocrit Levels In Walleye Sander Vitreus From Similar Waterbodies, Alyssa Hauser Jan 2022

Analysis Of Hematocrit Levels In Walleye Sander Vitreus From Similar Waterbodies, Alyssa Hauser

Journal of Earth and Life Science

Walleye Sander vitreus are a popular fish among anglers and hold a prominent place in Minnesotan’s identity as their state fish. Because of this, multiple management practices are used to ensure the continued health of their populations within Minnesota waters. In this study, the process of analyzing hematocrit levels was used to determine if the analysis of hematological parameters could be a useful tool in detecting differences in population health. To evaluate this, blood samples were acquired from age-0 and age-1 fish from two similar lakes and run through a hematocrit centrifuge to separate platelets from plasma to read the …


Walleye Sander Vitreus Visceral Fat Accumulation, Cole Daleiden, Seth Renner Jan 2020

Walleye Sander Vitreus Visceral Fat Accumulation, Cole Daleiden, Seth Renner

Journal of Earth and Life Science

For ectothermic species, proper lipid retention is critical to surviving in regions with limited growing seasons. Visceral fat is the dominant form of this energy storage in fish. Build up and depletion of these lipids occur seasonally as activity levels change throughout winter and spring. Due to this annual pattern, the purpose of this study is to determine a trend in the amount of visceral fat Walleye Sander vitreus accumulate in a time of year when metabolic rates are low and transition into the spawning process has yet to occur. Angling was the method of capture conducted during the months …


Changes In Walleye Fecundity And Egg Size Before, During, And After Rehabilitation Of The Red Lakes Fishery, Benjamin J. Miller, Benjamin D. Erb Jan 2019

Changes In Walleye Fecundity And Egg Size Before, During, And After Rehabilitation Of The Red Lakes Fishery, Benjamin J. Miller, Benjamin D. Erb

Journal of Earth and Life Science

The Red Lakes in northern Minnesota experienced a major Walleye Sander vitreus fishery crash in the late 20th century, but has since recovered to record abundances and supports a major commercial and recreational fishery. Fecundity is an integral aspect of recruitment that can contribute greatly to the understanding of fishery population dynamics. To elucidate the effects of varying Walleye densities and exploitation rates on fecundity and egg size in years 1989 (overexploited fishery), 2004 (recovering fishery), and 2017 (recovered fishery), we analyzed linear models that related fecundity or egg size to morphological features for these three sampling periods. Walleyes were …


Growth Rate And Hatch Date Of Age-0 Fishes On Leech Lake, Minnesota Before Zebra Mussel Establishment, Kayla Morey, Emily Larson Jan 2018

Growth Rate And Hatch Date Of Age-0 Fishes On Leech Lake, Minnesota Before Zebra Mussel Establishment, Kayla Morey, Emily Larson

Journal of Earth and Life Science

The introduction of an invasive species to an ecosystem is considered a very severe environmental problem. Zebra Mussel veligers Dreissena polymorpha have recently been found in Leech Lake, Minnesota, and are likely going to have a large influence on this ecosystem. Zebra Mussels are filter-feeders that rely on phytoplankton and zooplankton as their main source of energy. A shift in populations of plankton due to Zebra Mussels may affect the growth rates of larval fish. Median hatch dates and growth rates were estimated from four age-0 fish species (Yellow Perch Perca flavescens, Walleye Sander vitreus, Smallmouth Bass Micropterus …


Age-0 Walleye Growth Rates Following Spiny Water Flea Bythotrephes Longimanus Invasion, Joseph Amundson Jan 2018

Age-0 Walleye Growth Rates Following Spiny Water Flea Bythotrephes Longimanus Invasion, Joseph Amundson

Journal of Earth and Life Science

Within Voyageurs National Park, spiny water flea Bythotrephes longimanus has reduced Lake Kabetogama and Rainy Lake native zooplankton biomass during summer peak by 40-60%. Subsequently, planktivorous age-0 Yellow Perch Perca flavescens growth has decreased. A possible trophic cascade may influence predatory fish growth rates like that of age-0 Walleye Sander vitreus. Using seine net and electrofishing data, age-0 Walleye growth rates were modeled as a linear function of growing degree days (GDD) and the slope was compared between pre- and post-spiny water flea establishment. Nearby Lake Vermilion, assumed to have been unaffected by spiny water flea until 2015 and …


Relationship Between Zooplankton And Walleye Rearing Pond Success, Danny Tuckett Jan 2017

Relationship Between Zooplankton And Walleye Rearing Pond Success, Danny Tuckett

Journal of Earth and Life Science

Walleye Sander vitreus are an important sport fish in Minnesota. This has led to the raising of Walleye in ponds to later be stocked into lakes. This study was done to determine the relationship between Walleye prey (zooplankton) and the success of Walleye in 11 stocked ponds in the Ortonville, MN area. There was no management of the ponds until harvest, which starts in late September and ends in November. There were significant positive relationships between rotifer density (P = 0.03) and nauplii density (P = 0.04) to kg of Walleye harvested. The setting where nauplii and rotifer density are …


Changing Body Condition In Walleye With Reference To Ideal Sample Size Requirements, Kevin Longtin Jan 2014

Changing Body Condition In Walleye With Reference To Ideal Sample Size Requirements, Kevin Longtin

Journal of Earth and Life Science

The objective of this study was to determine if walleye Sander vitreus percent dry weight, a measure of condition, differed among summer months of 2014 on Maple Lake, Minnesota. A second objective was to determine if there was a relationship between condition and body temperature, total length, or wet weight. Between three and six walleyes were collected per month by hook and line methods. All fish had internal body temperatures taken at the time of capture and were oven dried in the laboratory at 80 °C in order to measure percent dry weight. There was no relationship between condition and …


White Bass Assessment In Regards To Changes In Water Level On Lake Traverse, Aaron Wilson Jan 2013

White Bass Assessment In Regards To Changes In Water Level On Lake Traverse, Aaron Wilson

Journal of Earth and Life Science

Until recently the white bass Morone chrysops has been somewhat ignored by anglers, more so in Minnesota than other states; most likely due to their limited distribution throughout the state. However, with more anglers becoming aware of the sporting and culinary potentials of white bass, interests have risen. With this rise in angler interest, there should be a rise in white bass assessments. Knowing what factors may be influencing white bass population dynamics will allow fisheries professionals to better manage and protect white bass fisheries. White bass are often found in rivers and impoundments were dams are present and water …