Environmental Sciences Commons^™

Effects Of Increasing Temperature And Acidification On The Growth And Competitive Success Of Alexandrium Catenella From The Gulf Of Maine, Drajad Seto

Electronic Theses and Dissertations

The increases in ocean temperature and pCO2 due to climate change are projected to affect the growth and future prevalence of Harmful Algal Blooms (HABs) in nearshore waters, but systematic studies on the effects these climate drivers have on harmful algal species are lacking. In particular, little is known about how future climate scenarios will affect the growth of the toxic dinoflagellate Alexandrium catenella, which produces the toxins responsible for paralytic shellfish poisoning (PSP) that threaten the health and economy of coastal communities in the Gulf of Maine. I examined growth responses of A. catenella and two other naturally co-occurring …

Stream Dynamics In The Headwaters Of Post-Glacial Watershed Systems, Brett Gerard

Electronic Theses and Dissertations

This dissertation summarizes research examining watershed processes across Northern New England, with an emphasis on the Central and Coastal regions of Maine. The research presented here focuses on the linkages between watershed geomorphic conditions, climate, and surface flow regimes driving stream channel hydraulic conditions and bed dynamics governing channel geometry. The geologic and human history of the landscape provides the context in which earth surface processes are examined within the dominant physiographic settings in Maine to describe vulnerabilities to climate change. Results are summarized to support the development of sustainability solutions for forecasted watershed management problems by natural resource management …

Mercury In Big Cypress Bayou And Caddo Lake Watersheds In Marion And Harrison Counties Texas, Joseph Watkins

Electronic Theses and Dissertations

Caddo Lake has been included on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury (Hg) content since 1996. One of the primary tributaries, Big Cypress Bayou, flows across Eocene-aged rocks and sediments associated with the Wilcox Group; the Wilcox is of interest because it contains lignite coal, which has a direct link to mercury. Previous research has focused on dry deposition from fossil fuel combustion as the primary source of mercury but has not addressed the potential watershed contribution to mercury concentrations in Caddo Lake.

Big Cypress Bayou flows through Harrison and Marion counties in …

Imidacloprid Persistence, Mobility, And Effect On Ecosystem Function, Joanna Hardin

Electronic Theses and Dissertations

Imidacloprid is a neonicotinoid pesticide used to protect against biting and sucking insects. Land managers rely on its systemic properties, however long-term studies investigating imidacloprid effects on ecosystem function are limited. This study investigated imidacloprid applications to Tsuga caroliniana and Tsuga canadensis over time and compared concentrations to measures of ecosystem function including soil respiration, microbial function, and invertebrate density. Results indicate that imidacloprid is persistent (p0.5). Microbial function and invertebrate density were not significantly different between control and treatment locations nor did imidacloprid concentrations correlate with ecosystem functional indicator activity (p>0.05). It is evident that imidacloprid does not …

The Ecology Of Fecal Indicators, Dennis A. Gilfillan

Electronic Theses and Dissertations

Animal and human wastes introduce pathogens into rivers and streams, creating human health and economic burdens. While direct monitoring for pathogens is possible, it is impractical due to the sporadic distribution of pathogens, cost to identify, and health risks to laboratory workers. To overcome these issues, fecal indicator organisms are used to estimate the presence of pathogens. Although fecal indicators generally protect public health, they fall short in their utility because of difficulties in public health risk characterization, inconsistent correlations with pathogens, weak source identification, and their potential to persist in environments with no point sources of fecal pollution. This …

Improving Sinkhole Mapping Using Lidar Data And Locating Sinkhole Hotspots In Johnson City, Tn, Kingsley Fasesin

Electronic Theses and Dissertations

Predicting infrastructure damage and economic impact of sinkholes requires high accuracy mapping distribution and development. The study mapped sinkholes and sinkhole hotpsots in Johnson City, TN using LiDAR-derived Digital Elevation Model (DEM) and a database of known sinkholes which were matched to LiDAR-derived depressions. For all matched depressions (n = 404), three metrics were calculated: circularity index, ratio of length to width of the Minimum Bounding Rectangle (MBR) and percent coverage of the MBR by the depression, and 3,634 new sinkholes were identified. Newly developed hotspots were identified in north Johnson City and other areas in the south near the …

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …

Effectiveness Of Prescribed Fire On Meeting Fuel Load And Wildlife Habitat Management Objectives In East Texas National Forests, Trey Wall

Electronic Theses and Dissertations

Using standardized methodology outlined by the United States Forest Service and the National Forests and Grasslands in Texas’ Fire Monitoring Program for data collection, the efficacy of current Forest Service prescribed burn regimes were analyzed for 24 study sites in East Texas National Forests. Study sites were located within Sam Houston, Davy Crockett, and Angelina/Sabine National Forests. Efficacy was determined by comparing defined management objectives established by the Forest Service to the data collected at the study sites. The results conclude that most objectives, as outlined by the Forest Service, are not being met with the current practices. Re-visitation of …

Modern And Paleoecological Perspectives On A Terrestrial-Marine Linkage In The Falkland Islands, Dulcinea V. Groff

Electronic Theses and Dissertations

The Falkland Islands are a biodiversity hotspot in the South Atlantic Ocean, with some of the world’s most important populations of seabirds and seals. The impact of climate change on these marine populations and their coastal breeding habitat in the Falklands is unknown. Coastal grasslands of Poa flabellata (tussac grass) form critical breeding habitat for wildlife, but have been heavily degraded by the introduction of livestock in the 17^th century. This dissertation investigates the impacts of global change (climate change, grazing) on P. flabellata and its sensitivity to the fecal nutrient subsidies provided by marine wildlife. Chapter 1 provides …

Nitrogen Cycling During A Period Of Environmental Change, Kaizad Patel

Electronic Theses and Dissertations

Natural and anthropogenic disturbances have altered the N cycle on the regional to global scale. Although numerous studies have examined the effects of chronic atmospheric N deposition on ecosystem processes, less is known about intra-annual variability of these processes, or how these responses might be altered under conditions of changing climate. The work described in this dissertation focuses on the effects of a changing chemical and physical climate, particularly terrestrial N processes (a) during Maine’s changing winters, and (b) in response to chronic elevated N additions.

Subnivean winter soil processes were examined at the Dwight B. DeMerritt Forest (DBDF) and …

Understanding Student Development Of Science Literacy Skills In An Undergraduate Environmental Science Course, Molly Picillo

Electronic Theses and Dissertations

Educators are expected to instill a variety of skills in their students that are necessary to be competent citizens of society. One such set of skills, science literacy skills, broadly encompass the ability of an individual to evaluate reliability of data and information and critically analyze and interpret them (Gormally Brickman, Hallar, & Armstrong, 2009). These skills are utilized in everyday decision-making and given their pertinence, there is a need for citizens to be scientifically literate. Thus, educators need tools and assessments to help students develop these skills and analyze their science literacy. The aim of this study was to …

Economics Of Managing Loblolly Pine Plantations For Increased Wildlife Biodiversity, Melissa Griffith

Electronic Theses and Dissertations

The goal of this thesis was to identify the differences between the costs incurred and revenues gained from managing loblolly pine (Pinus taeda) plantations in East Texas for strictly timber production or a combination of timber production and wildlife biodiversity. Management regimes evaluated had varying planting densities, thinning frequency and intensities, prescribed burn intervals, and site indices. Economic analyses used to evaluate management regimes over a range of nonindustrial private landowner (NIPF) alternative rates of return (ARRs) and site indexes were net present worth, land expectation value, and equal annual annuity. These economic analyses demonstrated that altering management …

Comparison Of A Modified And Traditional Rapid Infiltration Basin For Treatment And Control Of Nutrients In Wastewater Effluent, Jessica Cormier

Electronic Theses and Dissertations

Rapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water disposal. Few, if any, studies have been published where BAM-modified RIBs have been used for this purpose. In this work, a mixture of clay, tire crumb, …

Hydrodynamic Drivers Of Dissolved Oxygen Variability Within A Highly Developed Tidal Creek In Myrtle Beach, South Carolina, Douglas Matthew Pastore

Electronic Theses and Dissertations

Erosion and water quality degradation have been observed in Singleton Swash in Myrtle Beach, SC, and have been hypothesized to be related to migration of the beach-face channel. Dredging this channel temporarily fixes erosional threats to nearby infrastructure but the effects on water quality are not well understood. It is hypothesized that variations in dissolved oxygen (DO) concentration (used here as a proxy for water quality) within the water column are related to changes in vertical mixing and transport due to oceanic tidal forcing. This study utilizes current meters, pressure sensors, and optical DO probes to measure and study the …

Semi-Quantitative Assessment On Winyah Bay's Microplastic Contamination Levels, Samantha Ladewig

Electronic Theses and Dissertations

Although there is much concern globally regarding microplastic contamination in aquatic environments, there is little documentation on microplastic contamination concentrations within South Carolina inland waters and coastal areas. Specifically, Winyah Bay, SC should be of high priority for microplastic contamination evaluations as it is the third largest drainage basin (47,060 km2) and the second largest (157 km2) estuarine system on the east coast of the United States. Today, the general influencing physical factors on microplastic transport are mostly known by the scientific community, however, transport and deposition patterns of microplastics heavily vary by location depending on various physical, chemical, and …

Environmental Assessment Of Road Brining And Injection Wells For Disposal Of Oil And Gas Liquid Waste, Marissa Madia

Electronic Theses and Dissertations

The dramatic increase in oil and gas drilling operations in Pennsylvania over the last decade has presented a challenge for their wastewater disposal (e.g., flowback, produced water). Currently, these fluids are treated in permitted brine treatment plants or exported out of state to deep injection well facilities. In Pennsylvania, road brining for dust control is permitted for conventional well brines, and permits for three injection wells for unconventional brines are pending. This study focused on water quality impacts due to road brining in Farmington Township (45 samples) and ground and surface water in Grant Township (41 samples) prior to the …

Speleogenetic Evolution And Geological Remote Sensing Of The Gypsum Plain, Eddy County, New Mexico, Jessica Shields

Electronic Theses and Dissertations

Permian evaporites of the Gypsum Plain region of the Delaware Basin host extensive karst phenomena, as well as unique diagenetic alterations of host strata. Because of the complex, poorly understood hydrogeologic system, little has been established concerning the relation and evolution of the overprinted, modern and ancient karst manifestations within the Gypsum Plain, as a whole. Through a combination of traditional field studies and the development of improved remote sensing methodologies, this study established the speleogenetic evolution of the Gypsum Plain in relation to the greater tectonic, stratigraphic, hydrogeologic and climatic history of the Delaware Basin. Emphasis was focused on …

Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish

Electronic Theses and Dissertations

Of the most iconic fish species in the world, the Atlantic cod (Gadus morhua, hereafter, cod) has been a mainstay in the North Atlantic for centuries. While many global fish stocks have received increased pressure with the advent of new, more efficient fishing technology in the mid-20^th century, exceptional pressure has been placed on this prized gadoid. Bycatch, or the unintended catch of organisms, is one of the biggest global fisheries issues. Directly resulting from the failed recovery of cod in the GoM, attention has been placed as to possible sources of unaccounted catch. Among the most …

New Approaches To Mapping Forest Conditions And Landscape Change From Moderate Resolution Remote Sensing Data Across The Species-Rich And Structurally Diverse Atlantic Northern Forest Of Northeastern North America, Kasey R. Legaard

Electronic Theses and Dissertations

The sustainable management of forest landscapes requires an understanding of the functional relationships between management practices, changes in landscape conditions, and ecological response. This presents a substantial need of spatial information in support of both applied research and adaptive management. Satellite remote sensing has the potential to address much of this need, but forest conditions and patterns of change remain difficult to synthesize over large areas and long time periods. Compounding this problem is error in forest attribute maps and consequent uncertainty in subsequent analyses. The research described in this document is directed at these long-standing problems.

Chapter 1 demonstrates …

Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain

Electronic Theses and Dissertations

Deep-sea corals are of conservation concern in the North Atlantic due to prolonged disturbances associated with the exploitation of natural resources and a changing environment. As a result, the recovery rates of deep-sea coral communities are of heightened interest. These recovery rates are suggested to be on the order of decades to millennia, based on slow growth rates and longevity, of various deep-sea coral species. In 2014 and 2017 two research cruises in the Gulf of Maine, collected samples of two locally dominant species, Primnoa resedaeformis and Paramuricea placomus. These specimen collections were coupled with video surveys, conducted by …

Immersed In Fire: The Use Of Virtual Reality As An Attitude Assessor And Boundary Object In Wildland Fire Management, Casey Olechnowicz

Electronic Theses and Dissertations

Interest in using prescribed burning as a forest management tool to promote forest health and regeneration is growing in Maine. The goal for this research was to better understand the way that the public perceives prescribed burning practices in wildland-urban interfaces, with an emphasis placed on how immersive imagery, closely related to virtual reality (VR), compares to traditional communication methods. We specifically focus on the social acceptability of prescribed burning and analyze how the level of immersive imagery is related to that acceptability (Ahn, 2015; Bricken, 1990; Fogg, Cuellar, and Danielson, 2009; Smith 2015; Wiederhold, Davis, and Wiederhold, 1998). The …

Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords

Electronic Theses and Dissertations

Coal has a questionable future with the potential exhaustion of available coal. Alternate sources of energy production should be considered, such as hydropower dams, or the more environmentally friendly, Run of River (RoR) hydropower system. This study seeks to answer the question: What is the potential for RoR hydroelectric systems in Eastern Kentucky counties with significant decreases in coal production and employment? I hypothesize that GIS will identify suitable sites within Pike County for RoR systems. Site suitability for Eastern Kentucky was assessed and determined that Pike County did not have a suitable physical environment for RoR systems. The power …

A Comparison Of Four Wetlands Assessment Procedures Relevant To The Alluvial Valleys Of East Texas, Amy Camp

Electronic Theses and Dissertations

Currently several methods are used by public and private entities to assess wetland functional condition in support of the Section 404 Clean Water Act program. Four of these are: Forested Wetlands in Alluvial Valleys of the Coastal Plain of the Southeastern United States (SEHGM); A Regional Guidebook for Applying the Hydrogeomorphic Approach to the Functional Assessment of Forested Wetlands in Alluvial Valleys of East Texas (ETXHGM); Texas Rapid Assessment Method (TXRAM); and the Wildlife Habitat Appraisal Procedure (WHAP). Little previous research compares wetland functional assessment methods. Results of the SEHGM, ETXHGM, TXRAM, and WHAP methods were compared on five East …

Marine Protected Areas In Areas Beyond National Jurisdiction: Defining "Success" For Conservation And Management, Emily Suzanne Nocito

Electronic Theses and Dissertations

With growing attention to and use of marine protected areas [MPAs], there are an increasing number of policy goals ascribed to these area-based management tools [ABMT]. One expectation is that an MPA can increase system “resilience”, yet oftentimes resilience – including whether we are considering social, economic or ecological resilience – stays unspecified. In recent years, there has also been a specific focus on MPAs as tools to promote climate change resilient ocean systems. Through a meta-analysis of the scientific literature and an analysis of over one thousand three hundred voluntary commitments made at the United Nation Ocean Conference, this …

Reducing Tillage In Small-Scale Permanent Bed Organic Vegetable Production Systems, Jeremiah D. Vallotton

Electronic Theses and Dissertations

The response of field-grown vegetable crops to reduced tillage and mulching in permanent beds was evaluated through measuring crop yields, weed pressure, earthworm counts, and soil basal respiration. Two vegetable crops (“Bush Delicata” squash and “Farao” cabbage) were started in April and May of 2016 and 2017 respectively, transplanted in late June, and harvested on 15-Sep-2016 and 25-Aug-2017. Fruit number and weight of squash, and head weight and feeding damage of cabbage were measured. These results suggest that intensive tillage (8” rototill every year) can be successfully reduced to alternating years of shallow (2”) rototilling and a less intensive form …

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …

Comparative Analysis Of Survival And Decay Of Fecal Indicator Bacteria In Bovine Feces And Freshwater Microcosms, Reem Tariq

Electronic Theses and Dissertations

Agricultural runoff can carry FIB that can pollute surface waters through the soil matrix. This study was designed to inspect the impact of temperature and matrix on the survival of FIB. The FIB were routinely enumerated over an 18-day period from fecal samples and freshwater microcosms maintained at 4oC, 22oC, and 35oC. It was found that the FIB studied underwent a primary growth of up to 1-log10 to 3-log10, highlighting the weakness of conventional FIB as indicators of pathogen contamination. The concentrations of FIB in the water phase were found to be significantly greater than those observed in the fecal …

An Examination Of Beta Diversity Indices And Their Predictors In Two Large-Scale Systems, Philip Schroeder

Electronic Theses and Dissertations

Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (γ) can be broken down into within-site diversity (α) and between-site diversity (β). In particular, it has been noticed that the β …

The Ecology Of Land Managers In Riparian Restoration, Lisa Buie Clark

Electronic Theses and Dissertations

While previous studies in restoration ecology have focused on the efficacy of direct management actions, the driving forces on management decisions (e.g., managers' characteristics or attitudes, environmental conditions) and the indirect impacts on restoration outcomes from management decisions (such as whether to collaborate) are quantified here for the first time. As a case study, I used data from 244 sites across the riparian Southwest US where the invasive shrubby tree Tamarix sp. was removed using various different methods. I surveyed and interviewed the 45 land managers who were responsible for the removal projects to determine their characteristics, attitudes, and …

Automated Cfd Optimization To Maximize Wind Farms Performance And Land Use, Rafael Valotta Rodrigues

Electronic Theses and Dissertations

In this research, a computational system was designed to analyze and optimize the layout of wind farms under variable operational conditions. At first, a wind turbine computational fluid dynamic (CFD) model was developed covering the near wake. The near wake flow field was validated against near wake velocity data from the MEXICO experiment. The CFD simulation demonstrated that the tip speed ratio and the pitch angle greatly influence the near wake behavior, affecting the velocity deficit and the turbulence intensity profile in this region. The CFD model was extended to cover the far wake, aiming to become a computational tool …