Physical Sciences and Mathematics Commons^™

Unraveling Sources Of Cyanate In The Marine Environment: Insights From Cyanate Distributions And Production During The Photochemical Degradation Of Dissolved Organic Matter, Rui Wang, Jihua Liu, Yongle Xu, Li Liu, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

Cyanate is a nitrogen and energy source for diverse marine microorganisms, playing important roles in the nitrogen cycle. Despite the extensive research on cyanate utilization, the sources of this nitrogen compound remain largely enigmatic. To unravel the sources of cyanate, distributions and production of cyanate during photochemical degradation of natural dissolved organic matter (DOM) were investigated across various environments, including freshwater, estuarine, coastal areas in Florida, and the continental and slope regions of the North American mid-Atlantic Ocean (NATL). Cyanate production was also examined during the photochemical degradation of exudates from a typical strain of Synechococcus, an important phytoplankton …

Habitat Heterogeneity In Nebraska Streams And Distribution Prediction For Tier-1 Cyprinids Using Multi-Scale Modeling Of Fluvial And Landscape Features, Connor P. Hart

School of Natural Resources: Dissertations, Theses, and Student Research

Multiscale environmental processes determine in-stream habitat conditions which drive species distributions. Habitat constitutes the physical template upon which ecological processes occur and species conduct life stage activities. Habitat heterogeneity promotes biodiversity of aquatic systems. Stream classification informs freshwater conservation by providing a useful framework to account for habitat heterogeneity, often based on landscape regions of similar environmental processes. A greater understanding of landscape-based classification frameworks as means to classify stream systems may improve understanding of drivers of biodiversity. Using Nebraska as a case study, on a statewide scale, objectives were 1) to characterize habitat availability for several at-risk fish species, …

Stream Restoration Effectiveness In Mullins Creek In Fayetteville, Arkansas, Amadeo Scott

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Lotic waterways are vital for habitat, food, water, and flood protection, but urbanization poses a major threat to their integrity. Runoff from urban surfaces leads to pollution, flashiness, loss of biodiversity, and other symptoms, also known as Urban Stream Syndrome (USS). To combat USS, streams can be restored, but most restorations are not monitored so their long-term effectiveness is unknown. This study quantitatively evaluated a decade-old stream restoration in Fayetteville, Arkansas, to assess its effectiveness in combating USS and achieving set restoration goals, and to gain insights for future restoration projects. Restoration goals included decreasing erosion and sedimentation, increasing pool …

Supporting Data For Figures In "Wind-Enhanced Separation Of Large-Scale River Plumes From Coastal Corners", Michael M. Whitney

Department of Marine Sciences

This archive contains the supporting data for figures in the manuscript "Wind-enhanced separation of large-scale river plumes from coastal corners" by Michael M. Whitney. This study analyzes idealized models to quantify how large-scale river plumes and wind-driven currents interact at perpendicular coastal corners. Data are from the Regional Ocean Modeling System (ROMS) results for idealized model configurations. The Zip file (Figure_data.zip) contains MATLAB data files, which are named FigureXX_data.mat. Variable names and units correspond to graphed data of each figure in manuscript. Full descriptions of research methods and results are included in manuscript.

Nutrient Dynamics Of Freshwater Estuarine Sediments Disturbed By Dredging, Ryan Allan John Roekle

Theses and Dissertations

This study examined the nutrient environment of sediments in the Milwaukee River estuary and the dynamics of those nutrients during simulated disturbance experiments within the context of large-scale dredging remediation. Surface sediments were collected from throughout the Milwaukee estuary (including river, harbor, and nearshore stations) by PONAR, centrifuged to separate porewater (interstitial water) from solid material, and filtered to further isolate and stabilize dissolved material. Porewaters were analyzed for dissolved nutrients including ammoniacal nitrogen (AN), nitrate, nitrite, and soluble reactive phosphorus (SRP). Surface sediment porewaters within the estuary were often highly enriched in AN and SRP, which were often 10-2000x …

From Mountain Streams To Urban Rivers: An Assessment Of Microplastic Sources And Characteristics, Macy Gustavus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plastic products are produced and discarded at an alarming rate. Bottles, bags, toys, and clothing break down into tiny plastic pieces called microplastics, ranging in size from an eraser on the top of a pencil to smaller in size than a red blood cell. Microplastics are becoming so common in the environment that they travel in the atmosphere, rivers, and ocean currents in ways that are similar to other types of Earth Systems Cycles (i.e., the water cycle). In this study, we explored microplastic sources and sinks in a freshwater river system and how seasonal changes in discharge affect how …

Mussel Squeeze: Dissolved Oxygen And Temperature Can “Squeeze” Zebra Mussels Out Of Invaded Reservoirs, Crysta A. Gantz, Rich Miller, Steve Wells, Mark Sytsma, Angela Lee Strecker

Environmental Sciences Faculty and Staff Publications

Zebra mussels (Dreissena polymorpha) are an aquatic invasive species that cause extensive economic and ecological impacts and are a management priority in areas outside of their native range. Survivorship and distribution of zebra mussels within a waterbody are thought to be influenced by temperature and dissolved oxygen conditions, but detailed information to confirm the importance of these environmental controls is necessary to inform management efforts. We measured planktonic zebra mussel veliger density and adult survivorship in San Justo Reservoir in central California to determine distribution and timing of spawning in relation to temperature and dissolved oxygen throughout winter, spring, and …

Arctic Ocean And Subarctic Seas Dynamics In A Changing Climate, Sarah B. Hall

Theses and Dissertations

Salinity is the primary determinant of the Arctic Ocean’s vertical density stratification in the upper ocean, which has major implications on the ocean’s physical dynamics alongside a period of rapidly declining sea ice. In recent decades, the Arctic’s freshwater content (FWC) has increased as a result of the accumulation of freshwater source inputs. Additional freshwater exported to the North Atlantic may hinder overturning processes that are vital to the regulation of global climate. This dissertation employs in situ measurements, satellite observations, and ocean model simulations to better understand salinity and freshwater changes in the Arctic Ocean during this changing climate. …

Type Of Synthetic Microfiber Influences Ingestion By Freshwater Worms, Sarah A. Martinez

Honors College Theses

Plastics enter the environment from many sources, including clothing made from synthetic textiles, which shed a form of microplastics (microfibers) during their production, use and disposal. The impacts of microfibers on freshwater organisms are relatively unknown, therefore we tested the hypothesis that short- and long-term effects of microfibers on the aquatic worm, Lumbriculus variegatus, depend on the type of synthetic microfiber present. Microcosms containing L. variegatus, sediment and water were exposed to either no fibers (control) or one of three microfiber treatments (nylon, polyester or olefin) at the same concentration for 48 hours or 28 days. At the …

Trophish: Building A Global Database Of Freshwater Trophic Interactions, Jacob M. Ridgway

Honors Thesis

Freshwater management and research frequently use the trophic data of freshwater fishes. Despite this fact, it is difficult to perform a simple search of dietary information for any one fish species. FishBase represents, to our knowledge, the largest compilation of freshwater dietary information to date. However, it excludes a large portion of the ecological literature due to its development taking place prior to the creation of most modern scientific search engines. Our project (TroPhish) is building upon FishBase by digitizing approximately 130 years of data from the fish predation literature. Data from the primary and grey (e.g. theses, dissertations, reports) …

Influence Of Nutrients And The Native On E. Coli Survival In The Beach Environment, Brigid Meyers

Theses and Dissertations

E. coli is used as an indicator for water quality to determine if water poses a health risk for pathogens. Past research has shown that E. coli is present in high numbers in freshwater beach sands distinct from fecal pollution events, yet the precise mechanism for their persistence in not well understood. Persistent E. coli populations in sand can resuspend into adjacent water and lead to increased beach closures when no threat is present. This work identifies factors that influence the survival of E. coli in sand using laboratory microcosms to replicate beach conditions. Microcosms were deployed to examine the …

Freshwater Composition And Connectivity Of The Connecticut River Plume During Ambient Flood Tides, Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. Macdonald, Kimberly D. Huguenard

Civil Engineering Faculty Scholarship

The Connecticut River plume interacts with the strong tidal currents of the ambient receiving waters in eastern Long Island Sound. The plume formed during ambient flood tides is studied as an example of tidal river plumes entering into energetic ambient tidal environments in estuaries or continental shelves. Conservative passive freshwater tracers within a high-resolution nested hydrodynamic model are applied to determine how source waters from different parts of the tidal cycle contribute to plume composition and interact with bounding plume fronts. The connection to source waters can be cut off only under low-discharge conditions, when tides reverse surface flow through …

Are Rural And Small Community Aerated Wastewater Stabilization Ponds A Neglected Source Of Microplastic Pollution?, Zhiqiang Gao, James V. Cizdziel, Kendall Wontor, Haitao Lu

Faculty and Student Publications

Wastewater treatment systems collect and treat sewage that includes microplastics (MPs). However, we are not aware of any studies on the occurrence and distribution of MPs in wastewater stabilization ponds (WSPs), which serve small communities worldwide. Here, we characterized MPs (~45 µm–5 mm) in an aerated WSP serving ~500 houses and an adjacent lake. Putative MPs were most abundant in duckweed (Lemna minor) and sludge (75 ± 22 and 12.8 ± 3.1 particles/g, respectively: ±1 standard deviation (SD), n = 6, dry weight). In the water, average concentrations (particles/L ± 1 SD, n = 6) were highest in the pond …

Data Supporting The Figures In "Freshwater Composition And Connectivity Of The Connecticut River Plume During Ambient Flood Tides", Michael M. Whitney

Department of Marine Sciences

Supporting data for figures in "Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides" by Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. MacDonald, Kimberly D. Huguenard. The scientific journal article is published in Frontiers in Marine Science (2021). The main objectives of this study on the Connecticut River plume formed during ambient flood tidal conditions are: 1) determining the contributions of river source waters from different parts of the tidal cycle and 2) quantifying the degree and spatial distribution of connectivity of these source waters with the bounding plume fronts. A high-resolution numerical …

Supporting Data For Figures In "Freshwater Composition And Connectivity Of The Connecticut River Plume During Ambient Flood Tides", Michael M. Whitney

Department of Marine Sciences

Supporting data for figures in "Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides" by Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. MacDonald, Kimberly D. Huguenard. The scientific journal article is published in Frontiers in Marine Science (2021). The main objectives of this study on the Connecticut River plume formed during ambient flood tidal conditions are: 1) determining the contributions of river source waters from different parts of the tidal cycle and 2) quantifying the degree and spatial distribution of connectivity of these source waters with the bounding plume fronts. A high-resolution numerical …

Supporting Data For "Freshwater Composition And Connectivity Of The Connecticut River Plume During Ambient Flood Tides", Michael M. Whitney

Department of Marine Sciences

Supporting data for figures in "Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides" by Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. MacDonald, Kimberly D. Huguenard. The scientific journal article is published in Frontiers in Marine Science (2021). The main objectives of this study on the Connecticut River plume formed during ambient flood tidal conditions are: 1) determining the contributions of river source waters from different parts of the tidal cycle and 2) quantifying the degree and spatial distribution of connectivity of these source waters with the bounding plume fronts. A high-resolution numerical …

From River To Sea: Improving Carbon System Measurement Methods For Use In Rivers, Estuaries, And Oceans, Ellie Hudson-Heck

USF Tampa Graduate Theses and Dissertations

Over the last 30 years, spectrophotometric methodologies have been developed, with increasing rigor, to accurately measure all four carbon system parameters: total alkalinity (A_T), total carbon (C_T), partial pressure of CO₂ (pCO₂), and pH. Spectrophotometric measurements of carbon system parameters rely on quantitative characterizations of the response of sulfonephthalein indicator dyes (e.g., meta-cresol purple (mCP), thymol blue (TB), and bromocresol purple (BCP)) to changing solution pH, as well the response of indicator physical-chemical characteristics to key environmental variables (salinity (S_P), temperature (T), and pressure). Until recently, the physical-chemical properties …

Microbial Assemblages In Relation To Host And Environmental Surroundings, Mark Fischer

Senior Honors Theses

The goal of this study was to determine if the microbiome between two crayfish microhabitats were different from one other, in addition to the surrounding water and sediment. This project was a field-based study in which all environmental samples and crayfish were collected from a central Virginian freshwater stream. Molecular techniques were employed to sequence bacterial DNA from the various sample types and Qiime 2 was used to analyze statistical differences. The results from this study aligned well with the initial hypothesis in that the alpha-diversities between all of the sample types were statistically different (P<0.05) except for the gill chamber and surrounding water microbial assemblages. In addition, the Beta-diversity was statistically different when the bacterial composition of one sample type was compared to the composition of the other samples (P<0.05). This data aids in our understanding of the significance of microbes within a freshwater ecosystem and how they are distributed among freshwater organisms, such as the crayfish.

The Flow Less Traveled: Documenting Independent Original Research On Fluid Flow Interactions In The Laurentian Great Lakes And Immediate Surroundings, Thomas F. Hansen

Theses and Dissertations

This work is a compilation of several research projects undertaken by the author. Each research effort identifies a problem that has been addressed traditionally using methods that are significantly costly, to such an extent that, in general, funding, convenience, and practicality are primary limiting factors to their effective implementation. In each case, the author has been able to either build upon existing, less expensive alternatives, or even invent novel approaches. The fundamental recurring research question is, can creative, even novel, computational approaches make more efficient use of resources to interpret or present data in such a way as to make …

Sediment-Water Fluxes Of Phosphorus And Trace Metals In The Maumee River, Northwest Ohio, Emily L. Holliday

Browse all Theses and Dissertations

Excess phosphorus (P) and nitrogen (N) in the western basin of Lake Erie drive annual cyanobacteria blooms and associated hypoxia events. The Maumee River inputs ~5% of the water load into the western basin and ~50% of annual P loadings. I quantified seasonal variability of net P and metals fluxes from sediments in the Maumee River at four stations from Defiance, Ohio, to Maumee Bay. Upriver sediments were, on average, a total and filtered P sink throughout the year (−19 ± 7 and −6 ± 3, respectively; all fluxes represent `net flux’ reported in µmol m−2 h−1). At the river …

Impact Of Disturbance Regimes On Community And Landscape Biodiversity In Atlantic Coastal Pine Barren Ecoregion Streams, Sean T. Mccanty

Graduate Doctoral Dissertations

Streams are dynamic systems shaped by geographic location, hydrology, riparian vegetation, and in-stream habitat. Furthermore, ecosystem disturbance plays a major role in structuring stream communities and ecosystem processes. Disturbances include natural occurrences, such as flooding, drought, and fire events and anthropogenic disturbances such as land use changes, damming, and pollution. Agricultural use acts as a press disturbance regime, homogenizing the surrounding landscape and simplifying in-stream habitat, leaving legacy effects after farming ceases. Active restoration is intended to ameliorate these effects by reintroducing variation, with the goal of shifting the ecosystem into a more diverse and natural state. The act of …

Effects Of Light, Nutrients, And Salts On Microbial Biofilm Productivity And Detrital Processing In Aquatic Mesocosms, Bethanie Brooke Howard-Parker

Graduate Theses and Dissertations

Anthropogenic activities associated with urbanization, agriculture, and resource extraction continue to increase to support increasing needs of the growing population. These activities increase the amounts of pollutants entering freshwater streams and put aquatic ecosystems at structural and functional risk. Aquatic microbes play an important role in detrital processing in streams as a key linkage in moving carbon from detrital stocks into aquatic food webs. My research investigates the effects of light, nutrients, and salts on detrital microbes and decomposition in freshwaters using a mesocosm approach. In chapter one, I modified a current priming effect (PE) hypothesis model to include light …

Coho Salmon (Oncorhynchus Kisutch) Dispersal And Life History Variations Among Humboldt Bay Watersheds, Madison J. Halloran

Cal Poly Humboldt theses and projects

The decline of Coho Salmon (Oncorhynchus kisutch) in California is the result of various anthropogenic effects across the landscape, affecting all stages of their anadromous life history. Monitoring a subset of the remaining populations is essential to evaluate the success of management actions and develop new restoration projects. Defining the appropriate spatial scale for this monitoring and restoration depends on the frequency and extent of dispersal of individuals across watershed boundaries. Coho Salmon life-cycle monitoring projects in California estimate the abundance of juveniles and adults over time in selected focal watersheds. If individuals frequently enter or leave the …

Salty Sensors, Fresh Ideas: The Use Of Molecular And Imaging Sensors In Understanding Plankton Dynamics Across Marine And Freshwater Ecosystems, Trisha Lyn Spanbauer, Christian Briseno-Avena, Kathleen Johnson Pitz, Elizabeth A. Suter

Faculty Works: Biology, Chemistry, and Environmental Studies

Understanding plankton dynamics in marine ecosystems has been advanced using in situ molecular and imaging instrumentation. A range of research objectives have been addressed through high‐resolution autonomous sampling, from food web characterization to harmful algal bloom dynamics. When used together, molecular and imaging sensors can cover the full‐size range, genetic identity, and life stages of plankton. Here, we briefly review a selection of in situ instrumentation developed for the collection of molecular and imaging information on plankton communities in marine ecosystems. In addition, we interviewed a selection of instrumentation developers to determine if the transfer of sensor technology from marine …

Population Dynamics Of The Freshwater Mussel Lampsilis Cardium Reintroduced In Nebraska, Lindsay M. Ohlman

School of Natural Resources: Dissertations, Theses, and Student Research

The global decline of native freshwater mussels has accelerated conservation projects that preserve and restore populations, but the complex life histories among species challenges biologists in determining the most effective management strategies. This study details the conservation of plain pocketbook, a Tier I threatened mussel species in Nebraska that was artificially propagated and reintroduced into 13 sites from autumn 2016 to summer 2017. The objectives of this study were: 1) determine how handling influences mussels, and 2) evaluate mussel growth and survival following introductions.

We conducted a laboratory experiment with age-2 plain pocketbook to assess the effects of handling on …

Ebullition Of Oxygen From Seagrasses Under Supersaturated Conditions, Matthew H. Long, Kevin Sutherland, Scott D. Wankel, David J. Burdige, Richard C. Zimmerman

OES Faculty Publications

Gas ebullition from aquatic systems to the atmosphere represents a potentially important fraction of primary production that goes unquantified by measurements of dissolved gas concentrations. Although gas ebullition from photosynthetic surfaces has often been observed, it is rarely quantified. The resulting underestimation of photosynthetic activity may significantly bias the determination of ecosystem trophic status and estimated rates of biogeochemical cycling from in situ measures of dissolved oxygen. Here, we quantified gas ebullition rates in Zostera marina meadows in Virginia, U.S.A. using simple funnel traps and analyzed the oxygen concentration and isotopic composition of the captured gas. Maximum hourly rates of …

Difference In Physical Traits Of Rocky Mountain Tailed Frogs In Burned And Unburned Streams, Daniel M. Franz

Undergraduate Theses, Professional Papers, and Capstone Artifacts

No abstract provided.

Collective Gradient Sensing In Fish Schools, James G. Puckett, Aawaz R. Pokhrel, Julia A. Giannini

Physics and Astronomy Faculty Publications

Throughout the animal kingdom, animals frequently benefit from living in groups. Models of collective behaviour show that simple local interactions are sufficient to generate group morphologies found in nature (swarms, flocks and mills). However, individuals also interact with the complex noisy environment in which they live. In this work, we experimentally investigate the group performance in navigating a noisy light gradient of two unrelated freshwater species: golden shiners (Notemigonuscrysoleucas) and rummy nose tetra (Hemigrammus bleheri). We find that tetras outperform shiners due to their innate individual ability to sense the environmental gradient. Using numerical simulations, we examine how group performance …

Assessment Of Mercury Content In Louisiana's Freshwater Fish And Its Association To Se Concentrations, Alexander David Reyes-Avila

LSU Master's Theses

Ample evidence has demonstrated the neurotoxic properties of organic Hg to humans. However, recent studies have proposed the protective effects of Se against organic Hg detected in marine fish. Louisiana’s freshwater bodies are exploited by recreational anglers that enjoy fishing as recreational activity and food source. Thus, testing of Hg in Louisiana was resumed in 2017 to update the state advisories. However, before drawing conclusions based solely on organic Hg, it might be useful to see how much Se is present in freshwater fish. The main objective of this study was to determine the Se:Hg molar ratio in Louisiana’s freshwater …

Determination Of Atrazine Concentration In Freshwaters Using Fluorescence Spectroscopy, Boniface Osei Amankona

Online Theses and Dissertations

Atrazine is the most widely used herbicides in USA, but its negative impact on aquatic ecosystem cannot be over-looked. Atrazine was traditionally determined through liquid/gas chromatography or IR spectroscopy. However, these methods are either time-consuming or costly, so fluorescence spectroscopy is investigated as a more cost and time efficient alternative. Literature value of the optimal wavelength of atrazine was found to be 350 nm emission. Experimental value for emission scanned of atrazine resulted in an optimal wavelength of 363 nm. Known and unknown concentrations of atrazine will be analyzed using fluorescence spectrophotometer to develop a calibration curve.

The calibration concentration …