Life Sciences Commons^™

Organic Matter Sources, Composition, And Quality In Rivers And Experimental Streams, Julia E. Kelso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organic matter (OM) is often considered the “currency” for ecosystem processes, such as respiration and primary production. OM in aquatic ecosystems is derived from multiple sources, and is a complex mixture of thousands of different chemical constituents. Therefore, it is difficult to identify all the sources of OM that enter and exit aquatic ecosystems. As humans develop undisturbed land, the rate at which terrestrial OM (e.g. soil and plants) and associated nutrients (e.g. nitrogen) enters rivers has increased. Increased nutrients may lead to increased primary production from aquatic plants and algae, potentially causing eutrophication and harmful algal blooms. …

Ulva Spp. Bloom Dynamics In A Hyper-Eutrophic Estuary: Jamaica Bay, New York, Annesia Lamb

Dissertations, Theses, and Capstone Projects

In this dissertation, I present three studies that further our understanding of macroalgae identity, growth, and proliferation. Eutrophication is prevalent in shallow coastal ecosystems world-wide. One of the ecosystem consequences is the development of a bloom forming green marine macroalgae, Ulva spp. Ulva can have negative effects such as Zostera spp. degradation, fish, and shellfish declines. I performed assessments of (1) identity of the bloom-forming Ulva and other macroalgae assemblage, (2) physical, chemical, and biological drivers of Ulva bloom growth and proliferation, and (3) optimal irradiance and temperature requirements for early growth stages in Ulva linza.

The first study …

Louisiana Urban And Suburban Homeowners’ Fertilizer Management Behavioral Beliefs, Intentions, And Past Behaviors, Natalie Levy

LSU Doctoral Dissertations

Nutrient runoff of nitrogen and phosphorus from improper lawn and landscape fertilization practices contributes to water quality issues within the Mississippi River drainage basin and the Northern Gulf of Mexico (NRC, 2009a; Robbins & Birkenholtz, 2003). The implementation of fertilizer best management practices has become a critical strategy for reducing nutrient runoff (Carey et al., 2012a; Carey et al., 2013; U.S. EPA, 2005). The purpose of this study was to determine if relationships exist among selected perceptual measures regarding home lawn and landscape fertilizer management practices among Louisiana urban and suburban homeowners. Ajzen’s (1991) Theory of Planned Behavior (TPB) was …

Next Generation Sequencing Methods For Coastal Zone Water Quality Monitoring, Catherine Iskrenko

HCNSO Student Capstones

When analyzing the water quality of the coastal zone, culture-based techniques have been utilized most often to identify Fecal Indicator Bacteria in samples. Since the advent of the Sanger Method for DNA sequencing, other techniques have arisen that provide significantly more information on the microorganisms in sample, but they are still not the mainstream for water quality analysis. This capstone reviews and compares culture-based techniques, DNA sequencing, RNA sequencing, qPCR for biomarker, and 16S rDNA sequencing to highlight their merits and shortcomings for analyzing environmental water samples. The technique presented that provides the broadest range of information (including the identification …

Impacts Of Sediment Dredging On Phosphorus Dynamics In A Restored Riparian Wetland, Kimberly Oldenborg

Masters Theses

Global reductions in biodiversity and water quality are having major consequences for ecosystem health and societal well-being. The restoration of riverine floodplains and wetlands provides an ideal opportunity to increase biodiversity and water quality because their hydrologic connectivity to adjacent streams and rivers promotes the formation of heterogeneous habitat while also facilitating their functioning as a nutrient sink, in general. However, many historic floodplains and riverine wetlands have been drained for the creation of agricultural land, resulting in an accumulation of nutrients in the soils. Therefore, restoration practices that hydrologically reconnect former agricultural land to an adjacent stream or river …

Assay Of The Reverse Osmosis Purified Water In The Life Science Building At Bowling Green State University, Ohio, Nicholas Mendenhall, Scott O. Rogers, Neocles B. Leontis

Honors Projects

Contaminated water sources can cause problems for scientific research and result in costly delays and failures of experiments. At Bowling Green State University, the reverse osmosis supply circulating in the Life Sciences Building has been measurably contaminated for nearly three years, corresponding to a change in servicing of the system. While servicing has been accelerated, the contamination in the system remains. The focus of this research was to identify the species of bacteria and fungi growing inside of the water system so that it might alert those servicing the system, and to begin to eliminate the contamination. Reverse osmosis water …

Validation Of A Water Quality Index For Lake Erie, Vaclava Hazukova

Masters Theses

This study validates a water quality index based on a diatom total phosphorus transfer function for monitoring of the Lake Erie’s pelagic zone. Lake Erie is again under the threat of cultural eutrophication, mostly due to the runoff of nutrients from the surrounding farmlands. Therefore, it is an issue of high importance to continue monitoring efforts in Lake Erie to assess further deterioration or progressive changes due to the restoration management practices. Diatom-biomonitoring represents one of the efficient and well-crafted tools to assess the actual conditions. However, indices of water quality based on diatom transfer functions are often used without …

Crayfish Harvesting Practices In The Southern Atchafalaya River Basin: Quantitative And Qualitative Assessment Of Harvester Techniques And Hydrologic Connectivity Influence On Harvesting Strategies, Ivan A. Vargas-Lopez

LSU Master's Theses

Fisheries produce important impacts around the world through the exploitation of a wide range of species. In Louisiana, crayfish is the most emblematic crustacean and supports a multi-million industry based on pond culture and harvest from natural habitats. Although the economic value (USD) of wild-harvested crayfish has decreased from 10% to 3% of total crayfish value from 2013 to 2015, wild harvested crayfish are highly desired by many consumers and have a strong socio-cultural importance in Louisiana and other Gulf of Mexico coastal regions. This project evaluated harvesting practices by: 1) field observation and mapping of harvest sites in southwestern …

Watered Down: The Challenges Of Managing Water Resources In Montana, Beau E. Baker

Graduate Student Theses, Dissertations, & Professional Papers

Like much of the American West, Montana sits in the cross hairs of climate change. State drought resiliency projects and cooperative watershed management are on the rise in the face of decreased snowpack, early runoff, precipitation variability and lower seasonal stream flows. Population growth, land use practices, recreation and tourism all contribute to pressures on state water supplies.

Montana is faced with the arrival of invasive species that threaten the ecological health of its lakes, rivers and streams. State budget constraints and depressed agency capacity are hurting our ability to fend off these threats. There’s a lack of public education …