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Bemidji State University

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Articles 1 - 30 of 52

Full-Text Articles in Natural Resources and Conservation

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 …

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When Words Flow Like Water: How The Enbridge Line 3 Pipeline Environmental Impact Statement Failed To Prevent Hydrogeologic Harm In Minnesota, Carly Gutzmann Jan 2026

When Words Flow Like Water: How The Enbridge Line 3 Pipeline Environmental Impact Statement Failed To Prevent Hydrogeologic Harm In Minnesota, Carly Gutzmann

Journal of Earth and Life Science

For the aquifers of Minnesota, the environmental impact statement (EIS) was a promise of protection that never left the page. An environmental impact statement is meant to be an aid in the decision making process in order to ensure that projects consider potential environmental harms that may occur. However, they are often used instead as another regulatory box to check, rather than as active considerations when planning. As such, a project plan can be flawed from the start—if project developers only consider environmental impacts after they have already put considerable time, effort, and funding into their project as-is, they may …

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Largemouth Bass Diet Changes Through The Summer In Central Minnesota, Ethan Kunz Jan 2026

Largemouth Bass Diet Changes Through The Summer In Central Minnesota, Ethan Kunz

Journal of Earth and Life Science

Largemouth Bass Micropterus nigricans is one of the most widespread fish species in the world, due in part to human introduction for angling. Largemouth Bass are opportunistic predators that will consume the largest prey they can often find; however, it has been shown that their diet mainly consists of invertebrates such as crayfish, with less focus on other fish species. This research aimed to determine what the Largemouth Bass diets in Central Minnesota consist of, and how they may change from the beginning of summer through the beginning of fall. A total of 174 Largemouth Bass were sampled from late …

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Effectiveness Of Walleye Stocking In Winter Kill Lakes, Tyler Haus Jan 2026

Effectiveness Of Walleye Stocking In Winter Kill Lakes, Tyler Haus

Journal of Earth and Life Science

Winter kill events, marked by extensive fish mortality due to hypoxic conditions under the ice, are a common phenomenon in shallow eutrophic lakes, especially in the northern lakes in the northern United States. These events can drastically alter fish communities and often result in the elimination of top predators. Though these lakes will typically slowly bounce back to what they were in a couple of years. This study evaluates the effectiveness of walleye, Sander vitreus, stocking in lakes after a winter kill. For this study, four known winter kill lakes that are consistently stocked with walleye were studied. Pre- …

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Assessing Urban–Rural Differences In Largemouth Bass Abundance In Minnesota, Jonathan Gates Jan 2026

Assessing Urban–Rural Differences In Largemouth Bass Abundance In Minnesota, Jonathan Gates

Journal of Earth and Life Science

Urbanization can significantly alter freshwater ecosystems and influence sport fish populations. This study examined differences in largemouth bass Micropterus nigricans catch-per-unit-effort (CPUE) between urban and rural lakes in Minnesota and evaluated temporal changes between 2000–2010 and 2011–2021. Forty lakes (20 urban, 20 rural) were selected using Minnesota Department of Natural Resources fisheries survey data. Lakes were classified using NLCD 2019 land cover data, with ≥10% developed land designated as urban. Nonparametric analyses (Wilcoxon rank-sum and signed-rank tests) were used to assess spatial and temporal differences in CPUE. Results showed that rural lakes had consistently higher median CPUE than urban lakes …

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Neonicotinoid Bioaccumulation In Bluegill And Bullhead Within Lake Julia And Lake Zumwalde, Jake Stuber Jan 2026

Neonicotinoid Bioaccumulation In Bluegill And Bullhead Within Lake Julia And Lake Zumwalde, Jake Stuber

Journal of Earth and Life Science

Brown Bullhead Ameiurus nebulosus, Yellow Bullhead Ameiurus natalis, and Bluegill Lepomis macrochirus are unique in their stark differences. Bullhead are scaleless bottom feeders that can tolerate high pollution and low O2 conditions. In contrast, Bluegill are scaled, aggressive nesters and are less tolerant of high pollutants or low-oxygen conditions. Among these pollutants include a class of chemicals called neonicotinoids (hereafter referred to as neonics). Neonics are a class of insecticides primarily used within agriculture and pest management. Due to the effectiveness, application has escalated on a global scale. They have been well documented by many toxicology assessments. …

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Powering The Machine, Draining The Planet: Whether U.S. Environmental Law Is Equipped To Regulate The Energy And Water Demands Of Ai Data Centers, Michael Marcu Jan 2026

Powering The Machine, Draining The Planet: Whether U.S. Environmental Law Is Equipped To Regulate The Energy And Water Demands Of Ai Data Centers, Michael Marcu

Journal of Earth and Life Science

Artificial intelligence (AI) data centers have become one of the United States' fastest-growing and least-regulated sources of environmental stress. In 2024 alone, U.S. data centers consumed 183 terawatt-hours (TWh) of electricity more than the entire nation of Pakistan and consumed an estimated 17 billion gallons of water (IEA, 2025; Berkeley Lab, 2024). By 2030, electricity demand from these facilities is projected to reach 426 TWh, a 133% increase in six years (Pew Research Center, 2025). This paper examines whether the existing U.S. environmental regulatory framework put by the National Environmental Policy Act (NEPA), the Clean Water Act (CWA), and the …

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The Effect Of Zebra Mussels On Minnesota Fish Communities, Benjamin D. Strei Jan 2025

The Effect Of Zebra Mussels On Minnesota Fish Communities, Benjamin D. Strei

Journal of Earth and Life Science

Zebra mussels Dreissena polymorpha are an aquatic invasive species that has been spreading quickly throughout Minnesota water bodies since 1989. Zebra mussels are known to change certain morphological conditions in lakes such as turbidity, phytoplankton abundance, and aquatic invertebrate populations. However, studies showing impacts of the infestation of zebra mussels on the health of a fish community have been hard to prove due to a lack of repeated surveys and a suite of other confounding variables such as natural and seasonal variability, plant community, and lake morphometry. Therefore, the objective of this study is to determine whether zebra mussels have …

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Microsatellites Reveal The Population Genetic Structure Of Yellow Perch In Minnesota, Megan Boche Jan 2025

Microsatellites Reveal The Population Genetic Structure Of Yellow Perch In Minnesota, Megan Boche

Journal of Earth and Life Science

When analyzing a population’s genetic makeup, looking at variation of individuals and populations is a crucial factor. The management of yellow perch will be aided by this information particularly in regard to stocking or relocation. Microsatellite loci were used to analyze the genetic population structure of yellow perch Perca flavescens within and among 29 sampling areas throughout Minnesota’s basins. Seven microsatellite DNA loci were evaluated, with heterozygosities ranging from 0.41 to 0.78. The Lower Mississippi basin samples showed higher numbers of alleles per locus and greater expected heterozygosities compared to other basins, with Lake Pepin (PEP) exhibiting the highest average …

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Navigating Wastewater: Minnesota Mining Wastewater Permit Challenges And Evolving Compliance Standards, Madelaine Adamich Jan 2025

Navigating Wastewater: Minnesota Mining Wastewater Permit Challenges And Evolving Compliance Standards, Madelaine Adamich

Journal of Earth and Life Science

February of 2021 marked the beginning of Minnesota clearly establishing that groundwater qualifies as a Class 1 water in a legal battle involving United States Steel, the Minnesota Pollution Control Agency, WaterLegacy, Fond du Lac Band of Lake Superior Chippewa, the Minnesota Court of Appeals, and eventually the Minnesota Supreme Court (MNSC). Minnesota has a water classification system, as required by the federal Clean Water Act, with 7 classes of use. Class 1 waters are waters used for domestic consumption (MPCA 4, n.d.). According to Minnesota Statute § 7050.0220, the acceptable level for sulfate is 250 mg/L in Class 1 …

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Aquatic Invertebrate Populations In Roadside Wetlands In Relation To Water Characteristics, Ellen P. Isakson Jan 2025

Aquatic Invertebrate Populations In Roadside Wetlands In Relation To Water Characteristics, Ellen P. Isakson

Journal of Earth and Life Science

The continual habitat destruction and draining of wetland systems makes the need to understand the ecology of roadside wetlands all the more necessary. Roadside wetlands provide valuable habitat to countless aquatic invertebrates, which can provide insight into the health of the wetland system due to their diversity. The objective of this study was to analyze the populations of aquatic invertebrates in roadside wetlands in relation to water characteristics such as pH, salinity, conductivity, water depth and temperature, and dissolved oxygen. This was done by collecting samples of invertebrate populations from roadside wetlands, in addition to data on water quality characteristics …

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The Relationship Between Plant Density And Microplastic Concentration In The Water In Lake Bemidji, Mn, Arian Garcia Jan 2025

The Relationship Between Plant Density And Microplastic Concentration In The Water In Lake Bemidji, Mn, Arian Garcia

Journal of Earth and Life Science

Microplastics, plastic particles smaller than 5 mm, are an increasing environmental threat, particularly due to their widespread distribution and toxicity. While much research has focused on larger freshwater and marine ecosystems, the presence and impacts of microplastics in smaller inland lakes remain less understood. This study investigates the relationship between plant density and microplastic concentrations in Lake Bemidji, a smaller freshwater lake. A total of 30 water samples were collected across varying vegetation conditions, ranging from open water (0%) to 90% plant coverage. Microplastics were identified and categorized into six morphological types: fibers, fragments, films, spheres/beads, and foam. The samples …

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Effects Of Round-Up On The Environment, Sandra J. Marcu Jan 2025

Effects Of Round-Up On The Environment, Sandra J. Marcu

Journal of Earth and Life Science

Many people around the world have used and still currently use Roundup but are unaware of the effects it has on the environment. Roundup is a spray on application weedkiller that is widely used around the world today both residentially and commercially. It enables its user to grow a garden or a field of crops with a no-tilling approach to eliminate weeds. It is a well-known and popular choice for killing weeds that has been around since the mid 1970’s (Oca, 2017). John Franz, a Monsanto scientist discovered that glyphosate (main ingredient in Roundup) was an herbicide or weedkiller, and …

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The Effectiveness Of The Minnesota Buffer Law And Its Impacts On People, Ellen P. Isakson Jan 2025

The Effectiveness Of The Minnesota Buffer Law And Its Impacts On People, Ellen P. Isakson

Journal of Earth and Life Science

In January 2015, the then-governor of Minnesota Mark Dayton announced new legislation that would require 50-foot vegetation buffers along all waterways in Minnesota; this legislation would come to be known as the Minnesota buffer law, exact requirements being “perennial vegetative buffers of up to 50 feet along lakes, rivers, and streams and buffers of 16.5 feet along ditches” (Albert, 2017; MN Board of Water and Soil Resources [MN BWSR] 4 ). A buffer in the context of vegetation and natural resource management is a strip of vegetation around a body of water “designed to intercept stormwater runoff and minimize soil …

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Does Depth Affect Zebra Mussel Length In Scalp Lake?, Zanden Mellen Jan 2025

Does Depth Affect Zebra Mussel Length In Scalp Lake?, Zanden Mellen

Journal of Earth and Life Science

Since its first sighting in 1996, zebra mussels Dreissena polymorpha have been confirmed in hundreds of Minnesota lakes. Not only were they found in lakes, but they are also found in rivers too. With lack of effective treatments to impede their spread, zebra mussels continue to colonize new areas causing ecological as well as economic harm. The objective of this study was to see if there was a relationship between a zebra mussel length and the depth, they are found using shell length (mm) and depth (cm). The comparison of zebra mussel length and depth was done by performing a …

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Relationship Between Fishing Hours And Number Of Fish Harvested From Upper Red Lake, Dylan Ohlenkamp Jan 2024

Relationship Between Fishing Hours And Number Of Fish Harvested From Upper Red Lake, Dylan Ohlenkamp

Journal of Earth and Life Science

Total hours fishermen spend fishing and total amount of fish harvested per year are some of the most important pieces of knowledge gained from creel surveys. They provide crucial information that assesses fisheries mortality and pressure. MN DNR uses their results from creel surveys to improve or impose regulations, and to maintain healthy fisheries. Based on results from similar studies, there is expected to be a positive relationship between hours fished and fish harvested. To determine the relationship between these two variables on Upper Red Lake, data from two years were selected when the variables were at their highest and …

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Spatial And Temporal Variability Of Mercury In Upper And Lower Red Lake Walleye, Tyler Orgon Jan 2022

Spatial And Temporal Variability Of Mercury In Upper And Lower Red Lake Walleye, Tyler Orgon

Biology Graduate Theses

Mercury is a global pollutant that is released into our environment by natural and anthropogenic processes resulting in extensive studies conducted on mercury cycling in aquatic ecosystems which has led to the issuance of human-health-based fish-consumption advisories. We examined total mercury concentrations in Walleye Sander vitreus from Upper and Lower Red Lakes, located in north central Minnesota, between 2019 and 2020. Upper and Lower Red Lake form a contiguous water body consisting of two large (483.1 and 665.6 km2, respectively) basins that are naturally connected by a 1.4 km-wide strait. Both basins are important fisheries for recreation, subsistence, and commercial …

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Zebra Mussel Length-Weight Relationships Across Various Substrate Types In Lake Bemidji, Mitch Kehne Jan 2022

Zebra Mussel Length-Weight Relationships Across Various Substrate Types In Lake Bemidji, Mitch Kehne

Journal of Earth and Life Science

As of November 2021, zebra mussels were confirmed in 270 Minnesotan lakes with another 232 lakes listed as infested due to their connection or proximity to where zebra mussels have been found. With lack of effective treatments to impede their spread, zebra mussels continue to colonize new areas causing ecological as well as economic harm. The goal of this study was to establish a length-weight relationship for the zebra mussel population in Lake Bemidji using shell length (SL) and wet weight (WW), as well as to assess substrate type and log transformed shell length as predictors of log transformed zebra …

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Implications Of Condition Shifts On Shallow Lakes, Alicia Skolte Dec 2021

Implications Of Condition Shifts On Shallow Lakes, Alicia Skolte

Biology Graduate Theses

Shallow lakes have undergone condition shifts throughout time by natural causes, management actions, or a combination of the two. Because shallow lakes are especially vulnerable to shifts towards turbid conditions, management actions on shallow lakes have focused on water level/retainment, biomanipulations, the management/removal of non-native species, and land-use changes. This review compiles a summary on ecosystem shifts including a discussion on the frequency of shifts historically and the importance and causes of those shifts, trophic cascades, and the influence of introduced species in shallow lakes. This review will then examine case-studies of management-linked shifts and explain current shift theory. Next, …

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Feeding Patterns And Diet Overlap Of Muskellunge And Co-Occurring Piscivores In Minnesota Lakes, Kamden Glade Dec 2021

Feeding Patterns And Diet Overlap Of Muskellunge And Co-Occurring Piscivores In Minnesota Lakes, Kamden Glade

Biology Graduate Theses

Muskellunge Esox masquinongy are the largest member of the family Esocidae found in Minnesota and are managed for trophy angling opportunities with large minimum size requirements, limited harvest, and stocking to support existing populations or expand angling opportunities. While Muskellunge impacts at the community level appear minimal based on available literature, relatively little is known about Muskellunge diets, eat the le particularly in Minnesota. In this study, we used gastric lavage to examine gut contents of Muskellunge, Northern Pike Esox lucius, Walleye Sander vitreus, and Largemouth Bass Micropterus salmoides. Diets were quantified using an index of relative importance (IRI) and …

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Assessing The Dispersal And Recruitment Of Stocked Walleye Fry In A Northern Minnesota Chain Of Lakes, Joseph W. Amundson Oct 2021

Assessing The Dispersal And Recruitment Of Stocked Walleye Fry In A Northern Minnesota Chain Of Lakes, Joseph W. Amundson

Biology Graduate Theses

As part of Minnesota's Walleye Sander vitreus egg take practice, 10% of eggs taken for hatchery purposes are stocked back into the donor lake. For Andrusia, part of the Cass Lake Chain of Lakes (Chain), this practice can result in elevated fry densities (mean: 17,000 fry/littoral hectare). However, if fry are able to disperse and use all available littoral hectares throughout the Chain, fry densities would be intermediate to typical stocking densities for Minnesota lakes (1,200 - 2,400 fry/littoral hectare). In 2016-2018, 3-3.5 million fry were mass-marked by immersion in oxytetracycline (OTC) prior to stocking into Andrusia to allow differentiation …

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Factors Influencing Aquatic Invertebrate Diversity In Mine Pit Lakes Along The Mesabi Iron Range, Jeremy Laurich Jan 2021

Factors Influencing Aquatic Invertebrate Diversity In Mine Pit Lakes Along The Mesabi Iron Range, Jeremy Laurich

Journal of Earth and Life Science

Restoration of mine pit lakes for recreation is going to be very important for the future of Minnesota’s Mesabi Iron Range area. As many as 250 lakes will need to be restored in the future along this 100-kilometer-long swath of mining country. Information regarding the organisms that currently inhabit these lakes is important for future restorations to be a success. The focus of this study was to identify the types of aquatic invertebrates present in pit lakes and to identify some of the factors that influence their abundance and diversity. During this study, invertebrate samples were taken along the shore …

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Using Northern Pike And Yellow Perch To Attempt A Trophic Cascade, Bryan Sea Jan 2020

Using Northern Pike And Yellow Perch To Attempt A Trophic Cascade, Bryan Sea

Journal of Earth and Life Science

In the midwestern USA, water clarity has decreased in shallow lakes as a result of large populations of Fathead Minnow Pimephales promelas and agriculture that impact the life that depend on shallow habitats, such as waterfowl, fish, and aquatic plants. Northern Pike Esox lucius and Yellow Perch Perca flavescens were stocked in a few lakes in attempt to create a tropic cascade and reduce populations of nuisance Fathead Minnows. Northern Pike were stocked as fry and Yellow Perch were stocked as adults either pre-spawn or post-spawn. Lake managers hypothesized adult Yellow Perch would spawn and the age-0 Perch would feed …

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Effect Of Beaver On Brook Trout Habitat In North Shore, Lake Superior Streams, Kathryn Renik Aug 2019

Effect Of Beaver On Brook Trout Habitat In North Shore, Lake Superior Streams, Kathryn Renik

Biology Graduate Theses

In Minnesota, North American Beavers Castor canadensis (hereafter Beaver) are considered to have an overall negative affect on native Brook Trout Salvelinus fontinalis. Brook Trout provide a valued and productive sport fishery to the North Shore streams of Lake Superior and since revival of the Beaver population from past trapping and timber harvest, a reexamination of the complex ecological relationship where the two taxa interact is imperative. Suitable Brook Trout habitat is characterized by cold, spring- fed water with silt-free rocky substrate and abundant cover, all of which Beaver may directly, or indirectly, affect. Data collection occurred on 79 (200 …

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Spatial And Temporal Variability In Post-Larval Yellow Perch Density, Steve Hauschildt Feb 2019

Spatial And Temporal Variability In Post-Larval Yellow Perch Density, Steve Hauschildt

Biology Graduate Theses

Yellow Perch Perca flavescens are important as forage for other species and for sport fishing in many northern lakes. However, estimating post-larval Yellow Perch populations can be difficult because of many environmental factors that cause unexplained variation. The objective of this study was to help reduce unexplained variation by determining a post-larval Yellow Perch population density estimate on Blackduck Lake, MN, provide guidance to help determine the number of trawls required for trawling-based recruitment indices to achieve varying levels of precision, and test for the effects of wind speed and direction on post-larval Yellow Perch spatial variability. This study estimated …

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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 …

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Growth Of Pelagic Age-0 Yellow Perch In Relation To Hatch Dates And Water Temperature In North-Central Minnesota Lakes, Ethan Karppinen Aug 2018

Growth Of Pelagic Age-0 Yellow Perch In Relation To Hatch Dates And Water Temperature In North-Central Minnesota Lakes, Ethan Karppinen

Biology Graduate Theses

Exposure to consistent water warming rates and access to abundant populations of edible sized zooplankton affects growth and increases the probability of survival for newly hatched Yellow Perch Perca flavescens. Seven lakes with varying physical characteristics were selected in north-central Minnesota to study abiotic (water temperature) and biotic (zooplankton community and fish growth) progressions during the spring and early summer (April-June). Mean water temperatures from ice-out to 28 June (11.98-14.62 °C) had significant relationships with mean depth (P < 0.01, R? = 0.85), max depth (P < 0.01, R? = 0.73), and total volume (P < 0.01, R2 = 0.54). Hatch periods ranged from 13 to 19 days in 2015 and 13 to 25 days in 2016. Cumulative degree-days (CDD) were used to predict Yellow Perch hatch periods and explain growth. CDD predicted 21-81% of hatch periods in 2015 and 11-50% in 2016. Mean predicted total lengths at 28 June were 19.65-30.41 mm in 2015 and 20.88-28.54 mm in 2016. There was a significant relationship between CDD and predicted total length (R? = 0.62, P < 0.01) to explain differences in Yellow Perch total length while inhabiting the pelagic zone. Observed gape measurements were highly correlated with predicted gapes from the Schael formula (R? = 0.89, P < 0.01) that was used to assess the availability of edible sized zooplankton for age-0 Yellow Perch in each lake. No predator-prey mismatches were found and earlier hatch dates produced age-0 Yellow Perch with greater predicted total lengths in late June on the majority of lakes. This suggests that earlier hatched Yellow perch have an advantage over later hatched Yellow Perch in attaining greater lengths by late June. Our study provides information on a variety of physical and biological progressions in lakes, which may be used for fisheries management practices in the future.

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Population Characteristics Of A Closed Northern Pike (Esox Lucius) Catch-And-Release Population In Minnesota, John Kempe May 2018

Population Characteristics Of A Closed Northern Pike (Esox Lucius) Catch-And-Release Population In Minnesota, John Kempe

Biology Graduate Theses

Literature regarding catch-and-release populations of Northern Pike are rare and provide a unique perspective on their population dynamics. Shingobee Lake is a 64- ha mesotrophic lake with a maximum depth of 12.2 m located in northern Minnesota. Northern Pike fishing has been catch-and-release only since 2005, and there are no public accesses on the lake. Annual ice-out trap-netting occurred from 2009-2017, and a sizable amount of the Northern Pike recaptured via trapnet or angling had been previously tagged (37-59%). The lack of exploitation and high tagging percentage provided a unique opportunity to study the population dynamics of Northern Pike. Shinogbee’s …

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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 …

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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 …

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