Physical Sciences and Mathematics Commons^™

Anthropogenic Impacts To Essential Habitats In The Gulf Of Maine: A Case Study Of The American Lobster, Homarus Americanus, And Its Fishery, Andrew Goode

Electronic Theses and Dissertations

The Gulf of Maine has been fundamentally altered by anthropogenic forcings for decades and offers an ideal study system to monitor response to change. Through complex interactions between ocean warming, altered demographic bottlenecks, and reduced top-down controls, the American lobster (Homarus americanus Milne Edwards) capitalized on favorable conditions and proliferated within the Gulf of Maine. These changes catalyzed the expansion of the lobster fishery, elevated its status as North America’s most valuable marine resource, and shifted coastal communities towards a virtual lobster monoculture. The same processes that facilitated lobster to capitalize on favorable conditions may come with unintended consequences …

Biotic Interactions At Species’ Range Limits In A Changing Climate, Isaac Shepard

Electronic Theses and Dissertations

As the global climate changes, many species are shifting their geographic ranges, often towards the poles or upslope in elevation. The ubiquity of these observation has renewed discussions about the mechanisms that determine species’ range margins. Leading hypotheses state abiotic variables should be the most important factor for setting range limits in environmentally stressful habitats. However, I propose an alternative hypothesis that biotic interactions may still be critically important for setting range limits, even in abiotically stressful habitats. Using a model system of ponds in the Rocky Mountains of Colorado, I developed several field experiments to empirically test the role …

Forest Disturbance And Occupancy Patterns Of Carnivores: Results Of A Large-Scale Field Study In Maine, Usa, Bryn E. Evans

Electronic Theses and Dissertations

Understanding trends in the abundance and distribution of carnivores is important at global, regional and local scales due to their ecological role, their aesthetic and economic value, and the numerous threats to their populations. Carnivores in Maine range from the American black bear (Ursus americanus), to numerous native mesocarnivore species, such as American marten (Martes americana), fisher (Pekania pennanti), coyote (Canis latrans), red fox (Vulpes vulpes), bobcat (Lynx rufus), Canada lynx (Lynx canadensis) and to two small weasel species (Mustela erminea and Neogale frenata). …

Experimental Warming Effects On Growth, Yield, And Biotic Pressure Of Wild Blueberries In Maine, Yu-Ying Chen

Electronic Theses and Dissertations

As the global temperature rises, a need exists for understanding the potential impacts of warming on the wild blueberry industry in Maine. Warming can change the physiology, growth, and pest pressure of crops, and also accelerates the evapotranspiration rate, resulting in decreased soil moisture. The objectives of this study were: (1) To characterize the response of phenological, morphological, and physiological traits of the wild blueberries to warming; (2) To quantify the impacts of different temperature levels on yield and berry quality; (3) To determine the abiotic and biotic factors that may influence yield, such as winter damages, freezing temperatures, the …

A Remote Sensing Perspective: Mapping The Human Footprint In The Zambezi Region Of Namibia., Ariel E Weaver

Electronic Theses and Dissertations

The “human footprint” can be used as a general proxy to estimate human activities across the landscape. The human footprint in the Zambezi Region of Namibia is critically important for regional management of conservation efforts and land use planning. The land covers in the Zambezi Region are characteristically difficult to separate spectrally, due to a highly heterogeneous savanna landscape. Object Based Image Analysis (OBIA) and Random Forest (RF) methods are notable for their ability to improve classification accuracies of remotely sensed imagery. In this study, I investigate the extent of the human footprint in the Zambezi Region of Namibia, using …

Population Genetic Analyses Of Arctic Char (Salvelinus Alpinus) Life History Types In Nettilling Lake & Amadjuak River Ecosystem: A Test Of Reproductive Isolation, Chen Liu

Electronic Theses and Dissertations

A great number of studies have identified strong genetic differences between sympatric anadromous and resident populations of Salmonidae. However, Arctic char (Salvelinus alpinus) migratory phenotypes in the Nettilling Lake and Amadjuak River ecosystem in Nunavut, Canada have not been genetically characterized, and it remains unclear if distinct genotypes and phenotypes associated with migratory life history differences are maintained through reproductive isolation, and they have been assumed to be sympatric populations, or co-occurring populations. Co-occurring Arctic char (n=225) were sampled from eleven sites along the Amadjuak River in 2014 and 2015. Twelve microsatellite loci were used to quantify genetic variation among …

Multifaceted Environmental Enrichment In Industrial Fish Hatcheries: The Influence Of Enriched Rearing On The In-Situ Behaviour And Post-Stocking Success Of Juvenile Atlantic Salmon (Salmo Salar), Justine Elizabeth Mcandrews

Electronic Theses and Dissertations

Hatchery fish reared and stocked to sustain or restore wild populations often perform poorly in novel environments compared to their wild counterparts. To combat maladaptive hatchery-acquired traits environmental enrichment is an emerging tool used to provide ‘life skills training’ to hatchery fish prior to release. Through the application of simple yet multifaceted enrichment protocols in an industrial fish hatchery, this thesis aimed to demonstrate how enrichment could be applied to improve the ecological viability of stocked fish. At a provincially-run fish hatchery, a subgroup of juvenile Atlantic salmon (Salmo salar) were subject to 10 weeks of environmental enrichment …

Assessing The Adaptive Capacity Of An Arctic Seabird To Increasing Frequency In Predation Risk From Polar Bears Using Behavioural And Physiological Metrics, Erica Anne Geldart

Electronic Theses and Dissertations

Predator-prey dynamics in the Arctic are being altered with changing sea-ice phenology. The increasing frequency of predation on colonial nesting seabird eggs by a rare predator - the polar bear (Ursus maritimus), is a consequence of bears shifting to terrestrial food resources through a shortened seal-hunting season. I study a colony of nesting common eiders (Somateria mollissima) on Mitivik (East Bay) Island, Nunavut, Canada, that is exposed to established nest predators such as arctic fox (Vulpes lagopus), but has recently experienced an increase in polar bear nest predation due to the bears’ lost on-ice hunting opportunities. Given eiders’ limited eco-evolutionary …

The Development And Application Of Targeted Edna Metabarcoding For Monitoring Freshwater And Marine Ais, Yueyang Wu

Electronic Theses and Dissertations

Species invasions are of critical concern due to their significant impacts on ecosystems and social economies, of which aquatic invasive species (AIS) often pose significant challenges in their control and management, notably because of difficulties in early detection. Environmental DNA (eDNA) provides a promising tool in advancing the detection of newly introduced aquatic organisms because of its high sensitivity and ease of use compared to traditional capture-based methods. Although eDNA-based methods are increasingly used worldwide, especially in aquatic ecosystems, most studies focus on a limited number of target species despite a pressing need for broad taxonomic monitoring for conservation and …

Physiological State Determinants Of Maternal Cortisol Signaling And Its Impact On Offspring Quality And Fitness, Sydney Currier

Electronic Theses and Dissertations

Assessing the intergenerational effects of maternal stress is important for predicting how offspring will respond to changing environments. The overall aim of my thesis was to quantify the effects of maternal state on maternally derived egg cortisol and determine whether this variation in egg cortisol impacts Chinook salmon offspring performance and fitness in a sex-specific way. I quantified within-female changes in maternal energetics and reproductive metrics that I linked to egg quality and ultimately embryo survival. I found egg cortisol increases with increasing maternal plasma cortisol, and increases further as plasma cortisol levels rise with each day that eggs are …

To Know The Land With Hands And Minds: Negotiating Agricultural Knowledge In Late-Nineteenth-Century New England And Westphalia, Justus Hillebrand

Electronic Theses and Dissertations

Ever since the eighteenth century, experts have tried to tell farmers how to farm. The agricultural enlightenment in Europe marked the beginning of a long arc of new experts aiming to change agricultural knowledge and practice. This dissertation analyzes the pivotal period in the late nineteenth and early twentieth century in Germany and the United States when scientists, improvers, and market agents began to develop comprehensive ways to communicate agricultural innovation to farmers. In a functional approach to analyzing the negotiation of agricultural knowledge through its communication in things, words, and practices, this dissertation argues that the process of change …

Discards & Diverse Economies: Reuse In Rural Maine, Brieanne Berry

Electronic Theses and Dissertations

This dissertation presents an ethnographic exploration of diverse reuse economies in rural Maine in an effort to illuminate both how used goods move between people and organizations, as well as the value of that movement for people and communities. In response to a growing number of calls for research into the social dimensions of circular economies, this research explores the varied and uneven impacts of materials reuse as they are experienced by local participants. This work uses a qualitative approach, drawing on two main methods: participant observation in reuse establishments and in-depth, semi-structured interviews with reuse participants. This rich qualitative …

Investigation Of Ongoing Unconventional Gas Extraction And Underground Gas Storage In Pennsylvania: Regulations And Water Quality, Cassandra Ziegler

Electronic Theses and Dissertations

The extraction of unconventional shale gas and its underground gas storage have the potential to impact surface and groundwater water quality. In New Sewickley Township, Beaver County, Pennsylvania, 54 unconventional gas wells were drilled between 2013 and 2019. Groundwater samples from 33 water wells and surface water from Brush Creek (18 samples) were collected and analyzed for anions, cations, and light hydrocarbons. Results showed that at least 8 wells had indicators of brine contamination, and the surface waters of mine drainage. The Steckman Ridge natural gas storage field in Clearville, Bedford County, PA has 13 active storage wells. Samples were …

Impacts Of Oil And Gas Wastes On Landfill Leachate, Sewage Treatment Plants, And The Environment, Lauren Badertscher

Electronic Theses and Dissertations

Between January 2011 and March 2021 oil and gas wells in Pennsylvania produced

305,637,795 barrels of liquid waste and 6,992,957 tons of solid waste with the majority from

Marcellus Shale unconventional wells. This waste is not considered hazardous and over 89% of

the solid waste generated by unconventional and conventional oil and gas extraction has been

disposed of in landfills over the past decade. This study examined trends in the quantity of waste

produced and methods of disposal. Landfills accepting this waste were identified and their

general method of leachate treatment, using onsite facilities or offsite at wastewater treatment

plants, …

Development Of Standard Operating Procedure With Modified Method To Quantify Benzene And Other Volatile Organic Compounds In Air Samples Using Gas Chromatography, Heather Hall

Electronic Theses and Dissertations

Stephen F. Austin State University (SFASU) Department of Environmental Science has recently invested in a gas chromatograph which can be used to analyze air samples for volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylenes (BTEX). The goal of this project was to develop a standard operating procedure (SOP) and modify the current method for the detection of VOCs associated with oil and gas drilling activity to accommodate the equipment and capabilities of SFASU Environmental Assessment Lab. This study aims to provide the framework for future research in air quality monitoring in the Eagle Ford Shale area. An …

Using An Inventory Of Unstable Slopes To Prioritize Probabilistic Rockfall Modeling And Acid Base Accounting In Great Smoky Mountains National Park, Thomas A. O'Shea

Electronic Theses and Dissertations

An inventory of unstable slopes along transportation corridors and performance modeling are important components of geotechnical asset management in Great Smoky Mountains National Park (GRSM). Hazards and risk were assessed for 285 unstable slopes along 151 miles of roadway. A multi-criteria model was created to select fourteen sites for two-dimensional probabilistic rockfall simulations and Acid Base Accounting (ABA) tests. Simulations indicate that rock material would likely enter the roadway at all fourteen sites. ABA test results indicate that influence of significant acid-producing potential is generally confined to slaty rocks of the Anakeesta Formation and graphitic schist of the Wehutty Formation. …

The Effects Of Prescribed Burning On Soil Water Infiltration Rates And Other Select Soil Physical And Chemical Properties In East Texas, Cassady Pennington Dunson, Brian P. Oswald, Kenneth Farrish, Tyson Hart

Electronic Theses and Dissertations

This study focused on whether prescribed burning affects soil physical and chemical properties, especially water infiltration, in Western Gulf Coast forests. Soil water infiltration rates were measured 1) pre-burn (before the fire), 2) post-burn (one month after the fire), and 3) at vegetation green-up (three months after the fire). Soil samples were also collected to determine the effects of prescribed burning on soil pH, bulk density, particle density, pore space, soil strength, O-horizon weight and depth (organic matter), water stable aggregates, and soil fertility. This project was conducted on two different burn intervals. The National Forests and Grasslands of Texas …

Host-Microbiome Interactions: Chinook Salmon (Oncorhynchus Tshawytscha) Gut Immune Function And Bacterial Community Composition, Farwa Zaib

Electronic Theses and Dissertations

Population divergence through selection can drive local adaptation, which has implications for effectively restoring declining and extirpated populations. Salmonid species provide an excellent model system to explore locally adapted traits as they are reproductively isolated and experience diverse environments. Here we focused on integrated immune function, which is affected by variation in host genetics and gene transcription as well as gut microbiome (bacterial community) variation. Furthermore, we explore interactions between host gut gene transcription levels and bacterial community composition to test co-adaptation of the host and its microbiome. In chapter 2, we utilized a factorial breeding design to determine the …

Multifaceted Environmental Enrichment In Industrial Fish Hatcheries: The Influence Of Enriched Rearing On The In-Situ Behaviour And Post-Stocking Success Of Juvenile Atlantic Salmon (Salmo Salar), Justine Elizabeth Mcadrews

Electronic Theses and Dissertations

Hatchery fish reared and stocked to sustain or restore wild populations often perform poorly in novel environments compared to their wild counterparts. To combat maladaptive hatchery-acquired traits environmental enrichment is an emerging tool used to provide ‘life skills training’ to hatchery fish prior to release. Through the application of simple yet multifaceted enrichment protocols in an industrial fish hatchery, this thesis aimed to demonstrate how enrichment could be applied to improve the ecological viability of stocked fish. At a provincially-run fish hatchery, a subgroup of juvenile Atlantic salmon (Salmo salar) were subject to 10 weeks of environmental enrichment …

Development Of Nanostructured Titania-Incorporated Photocatalysts For Environmental Applications, Sudheera B. Yaparatne

Electronic Theses and Dissertations

Ultraviolet (UV) radiation application in water and wastewater treatment has become a common approach for inactivation of protozoa and other pathogenic microorganisms. However, degradation of most organic compounds, such as taste and odor products prevalent in surface waters, has not been proven effective with direct UV photolysis. Advanced oxidation processes (AOPs) that involve efficient photocatalysts like TiO₂ show an advantage over direct UV photolysis providing fast reaction rates and non-selective oxidation of contaminants. However, the real-world application of TiO₂ in water and wastewater treatment is limited due to difficulties in separating the suspended nanosized particles following treatment, the …

Assessing The Adaptive Capacity Of An Arctic Seabird To Increasing Frequency In Predation Risk From Polar Bears Using Behavioural And Physiological Metrics, Erica Anne Geldart

Electronic Theses and Dissertations

Predator-prey dynamics in the Arctic are being altered with changing sea-ice phenology. The increasing frequency of predation on colonial nesting seabird eggs by a rare predator - the polar bear (Ursus maritimus), is a consequence of bears shifting to terrestrial food resources through a shortened seal-hunting season. I study a colony of nesting common eiders (Somateria mollissima) on Mitivik (East Bay) Island, Nunavut, Canada, that is exposed to established nest predators such as arctic fox (Vulpes lagopus), but has recently experienced an increase in polar bear nest predation due to the bears’ lost on-ice hunting opportunities. Given eiders’ limited eco-evolutionary …

Evaluating Methods For Research In Physical Weed Control And Farm Asset Tracking, Johnny J. Sanchez

Electronic Theses and Dissertations

Effective weed control has long been recognized as critical for agricultural production, yet weeds remain a major constraint to production and economic return in many agroecosystems. Moreover, improvements in physical weed control are necessary to address increasing problems of herbicide resistance in weeds of grain and fiber crops and the high cost of hand weeding in vegetables. From tractor-mounted cultivation tools to autonomous weeders, weeding implements are affected by weeds, crops, soil conditions, and actuator effectiveness. In order to address these complex and often interacting factors concerning weed control, new and innovative tools must be designed and evaluated. Chapter one …

Air Pollution In The Steel City: Assessing The Influence Of Covid-19 On Air Pollution In Allegheny County, Carissa L. Lange

Electronic Theses and Dissertations

Though the novel coronavirus (COVID-19) has sickened millions of individuals, lockdown measures have provided a unique opportunity to analyze air pollution reductions. Reductions in air pollution are especially important in a city like Pittsburgh, where industrial activity has led to elevated levels of particulate matter with an aerodynamic diameter 2.5). The majority of this PM_2.5 pollution comes from two industrial facilities, the Edgar Thomson Steel Works and the Clairton Coke Works. By utilizing a natural experiment, this study sought to determine how large of a role the COVID-19 lockdowns played in improving air quality in the Pittsburgh region. Data …

Presence Of Severe Acute Respiratory Syndrome Coronavirus 2 In Urban Streams Receiving Sewer Overflow, Louisville, Kentucky, Usa., Cullen Hunter

Electronic Theses and Dissertations

Pathogens may enter surface waters as they are shed in human feces and potentially delivered to surface waters via sewer overflows, particularly in the eastern United States. This study examined of the presence of fecal indicators in two forks of Beargrass Creek in Louisville, Kentucky. Surface water grab samples (N=30), sediment samples, water quality, and a paired wastewater surveillance study were analyzed. SARS-CoV-2 was detected in a single stream sample despite ubiquitous presence of the virus within the area in wastewater and consistent evidence of a human fecal indicator. These findings demonstrate the need for more green and gray infrastructure …

An Eemd Approach To Non-Stationary, Non-Linear Environmental Long- And Short-Term Time Series Data Of Charleston, Sc, With A 2009 Flood Anomaly Case Study, Dylan David Carpenter

Electronic Theses and Dissertations

No abstract provided.

Quantification Of Climate Variability And Extreme Events In The Great Plains, Angelinah Ntsieng Rasoeu

Electronic Theses and Dissertations

Climate variability and extreme events continue to worsen resulting in significant impacts to society and the environment. Quantifying precipitation variability, streamflow, and extreme events at local scale is crucial for local planning and management due to spatial and temporal precipitation variability which influences streamflow and thus, water resources. This study uses statistical tools to analyze 1895-2019 (125 years) of historical precipitation data to examine how long-term precipitation varies annually, seasonally, and monthly, and create climate classifications. The results show that annual precipitation is increasing linearly over time ranging from 13.2 in (1976) to 43.1 in (2010) and 5 climate classes …

Revegetating Salt-Impacted Soils In The Northern Great Plains, Abigail P. Blanchard

Electronic Theses and Dissertations

In the northern Great Plains (NGP), an estimated 10.6 million hectares of land are affected by naturally occurring salt-impacted soil. Naturally occurring salt impaction results when rainfall causes salts in parent material to move upward through the soil profile and remain in the root zone causing osmotic and ionic stress, negatively affecting seed imbibition, germination, and plant growth. Common methods to remediate saltimpacted soils were developed in the irrigated soils of the Southwestern U.S., are ineffective in the non-irrigated soils of the NGP, and can exacerbate the problem. Therefore, new methods to remediate salt-impacted soil in the NGP are needed. …

Effects Of Harvest Regulations And Post-Release Hooking Mortality On Walleye Populations In South Dakota, Cade Lyon

Electronic Theses and Dissertations

Harvest regulations are commonly implemented to manipulate fisheries stocks. By regulating the size and number of fish that are harvested by anglers, managers are able to meet the goals and needs of regions. However, these management actions come with the potential for negative consequences. Overexploitation due to less restrictive harvest regulations can cause collapses in fisheries populations. In addition, indirect consequences such as hooking mortality brought on by length-based regulations can also be detrimental to populations. In this study, I investigated the effects of various harvest regulations on Walleye populations in three western South Dakota irrigation reservoirs: Angostura, Belle Fourche, …

Spatial And Temporal Patterns Of Sympatric Bobcats (Lynx Rufus) And Coyotes (Canis Latrans) In An Agricultural Landscape, Marlin M. Dart

Electronic Theses and Dissertations

Bobcat (Lynx rufus) populations experienced declines in the Midwest during the 20th century due to land conversion for agriculture and over exploitation and were practically nonexistent in areas by the 1970-80s. Populations have been recovering following changes in land-use practices and habitat improvement. Eastern South Dakota was closed to bobcat harvest in 1977 but reopened in 2012 to select counties. Bobcats are elusive, have large home ranges, and occur at low densities, making monitoring their populations difficult. Camera trapping is an effective tool for monitoring elusive carnivores but can be burdened by low detection rates. Researchers often employ …

Pheasant Ecology In An Agricultural Landscape Of South Dakota, Sprih Harsh

Electronic Theses and Dissertations

Habitat loss and fragmentation are the greatest threats to wildlife conservation. Grasslands are among the most threatened ecosystems worldwide. The large-scale conversion of North American grasslands to cultivation has been strongly associated with declines of grassland bird populations. The ring-necked pheasant (Phasianus colchicus) is a common grassland bird which is negatively impacted by the conversion of grassland to cropland. Though pheasants are non-native to South Dakota, they have become naturalized in most of the state. However, with increases in agricultural intensification in South Dakota, indices of pheasant abundance from brood route surveys suggest that pheasant populations have declined to historically …