Life Sciences Commons^™

Surveying The Circular Rep Encoding Single Stranded (Cress) Dna Viral Consortium Found In Invasive Quagga Mussels (Dreissena Rostriformis Bugensis) And Sediments Of The Central Lake Michigan Benthos, Nicholas Gezon

Masters Theses

Globalization and resulting increases in international trade has allowed for the movement of species between almost all ecosystems on Earth. The Great Lakes in particular has seen a number of high impact invasive species that have moved in following the opening of the lakes to intercontinental shipping trade. This research specifically focuses on the benthic community of Lake Michigan which has seen significant community shifts including declines of the amphipods Diporeia spp. and the expansion of invasive quagga mussels (Dreissena rostriformis bugensis). Little is known about the viral community in the benthos of Lake Michigan and how …

Brook Trout Behavioral Thermoregulation And Habitat Selection In A Small Michigan Coldwater Stream: Implications For Successful Management, Justin Emory Wegner

Masters Theses

Global warming and conversion of forests for urbanization, agriculture and mineral extraction are increasing water temperatures throughout Brook Trout’s range causing population declines; particularly in populations persisting in marginal habitats and in the southern limits of their distribution. The Brook Trout is an ectotherm that can cope with elevated water temperature by moving to coldwater refuge such as groundwater seeps, coldwater tributary confluences, and headwaters. Availability of coldwater refuge is vital for the survival of Brook Trout populations threatened by increasing water temperatures. I used radio telemetry to study the movement, habitat use, and behavioral thermoregulation of Brook Trout living …

Phosphorus Retention In West Michigan Two-Stage Agricultural Ditches, Emily Kindervater

Masters Theses

Input of excess nutrients into a water body can negatively impact ecological structure and function, as well as the economic vitality of surrounding communities, by contributing to eutrophication. For example, phosphorus (P) and sediment inputs from agricultural drainage have facilitated the development of hypereutrophic conditions in Lake Macatawa, a drowned river mouth lake located in Holland, Michigan. Two-stage ditches, an agricultural best management practice (BMP), are used in some areas of the Midwest to reduce N export downstream via denitrification. This BMP simulates a mini-floodplain by replacing a traditional, trapezoidal ditch with a channel that has excavated benches on each …

Identification Of Deletions In The Hdc Gene Of Drosophila Melanogaster Generated Through Transposon-Excision Mutagenesis, Gregory A. Wesseling

Masters Theses

Histamine is a biogenic amine that functions as a neurotransmitter in a number of vertebrate and invertebrate systems and is synthesized from its precursor histidine by the enzyme histidine decarboxylase (HDC). In Drosophila, histamine has been shown to have function in photoreceptors, mechanoreceptor cells, as well as centrally located neurons. Mutations of the Hdc gene, such as Hdc^JK910, exhibit defects in histamine synthesis and display altered behaviors such as blindness, inability to groom, impaired thermal tolerance, and altered sleep rhythms. However, all Hdc mutants obtained thus far demonstrate some transcriptional activity.

In order to remove Hdc expression …

Yellow Perch Genetic Stock Structure In Eastern Lake Michigan: What Is The Importance Of Drowned River Mouth Lakes?, Gregory M. Chorak

Masters Theses

Habitat heterogeneity has the possibility of structuring populations. Even in connected landscapes, there can be cryptic structuring of populations that coincides with landscape features that limit gene flow or select for different phenotypes within a species. Yellow perch (Perca flavescens) is an economically and ecologically prominent fish in the Laurentian Great Lakes. In the Lake Michigan basin, yellow perch reside in nearshore Lake Michigan, including drowned river mouths (DRMs, lake-like habitats that link tributaries to Lake Michigan). The goal of this study was to understand whether yellow perch populations are structured in eastern Lake Michigan by the connected …

Seasonal Ecology Of Mottled Sculpin And Brown Trout In A Coldwater Michigan Stream, Susanna K. Lagory

Masters Theses

In temperate regions, environmental conditions vary distinctly between seasons. This variation can strongly impact in-stream environmental conditions. Winter is often thought to be harsher than other seasons for stream fishes, given the adverse environmental conditions that arise from low temperatures during winter in temperate regions. Low temperatures, episodic elevated discharge, and ice formation associated with winter are hypothesized to reduce movement, body condition, and survival of stream fishes. However, few studies test this hypothesis through formal comparisons, and most studies of seasonal stream fish ecology focus on salmonids. To address this knowledge gap, I estimated and compared body condition, net …

Polychlorinated Biphenyl Concentrations In Fish From Lake Michigan Tributaries And A Preliminary Risk Assessment Concerning Their Consumption By Sport And Tribal Fishermen, Amanda K. Potter

Masters Theses

Human and environmental health continues to be threatened by persistent organic pollutants in the Great Lakes ecosystem. Polycholorinated biphenyls (PCBs) are considered one of the most toxic contaminants in the Great Lakes due to their recalcitrance, bioaccumulation, lipid solubility, and adverse health effects.

The three main questions examined in this research were: 1) Do PCB concentrations vary between largemouth bass (Micropterus salmoides), northern pike (Esox Lucius), smallmouth bass (Micropterus dolomieu), and walleye (Sander vitreus) in west Michigan tributaries of Lake Michigan; 2) Do PCB concentrations vary on a watershed level among Manistee …

Nest-Site Selection And Neonate Survival Of Eastern Box Turtles (Terrapene Carolina Carolina) In Michigan’S Northern Lower Peninsula, Joseph T. Altobelli

Masters Theses

Turtles (Order Testudines) are experiencing global declines largely due to anthropogenic influences such as habitat fragmentation, illegal collection and sales, and the threat of global climate change. Removal of individuals from the adult age-classes means there is now a greater need to understand the survival of neonate and juvenile turtle age-classes. In this study I examined a population of eastern box turtles (Terrapene carolina carolina) at the northern limit of their range in Michigan’s lower peninsula. The objectives of my thesis were 1. to determine the microhabitat factors that influence nestsite selection by female box turtles and how …

Effective Population Size, Demography, And Viability Of Eastern Massasaugas (Sistrurus Catenatus) In Southwest Michigan, Danielle R. Bradke

Masters Theses

As humans increasingly exploit natural areas, wildlife populations face a growing number of threats that often result in population decline and isolation. Small, isolated populations are vulnerable to extirpation due to both genetic and demographic factors. Yet, low detectability of many imperiled species often precludes the collection of population-level data important for assessing population viability and implementing successful conservation. The eastern massasauga (Sistrurus catenatus) is a cryptic pitviper that has been extirpated throughout much of its historic range due to agricultural conversion of wetland habitat and other synergistic threats. Consequently, this species is federally listed as threatened in both the …

Spatial Ecology Of The Adult And Neonate Eastern Box Turtle In A Forested Landscape, Patrick B. Laarman

Masters Theses

A thorough understanding of spatial ecology is fundamental when developing and implementing conservation strategies for imperiled turtle species. I investigated spatial ecology of adult and neonate eastern box turtles in the Manistee National Forest (MNF), Michigan. My primary objectives were to evaluate relative habitat preferences of adults and document residency time of neonates in natal openings. I radio-fitted 25 adults, protected 64 nests, and radio-fitted 66 neonates. Mean home range size for adults (n = 25 turtles) was 16.4 ha ± 2.4 SE (100% Minimum Convex Polygon). I detected non-random habitat use by adults (Wilks Ʌ = 0.202, df = …