Master of Science, University of Toledo, 2021, Biology (Ecology)

Chapter 2: Stratification and hypoxia in the western basin of Lake Erie (WBLE) has been shown to result in phosphorus flux from the underlying sediment, which could provide necessary nutrients for harmful algal bloom (HAB) growth. Studying the duration and frequency of hypoxic events would provide pivotal information for estimations of phosphorus flux from underlying sediments. However, due to the ephemeral nature of hypoxic events in the WBLE, planned weekly vessel-based sampling trips are inadequate for alerting researchers of the onset of hypoxia, making sampling such events difficult. Instead, water quality instruments can be deployed to collect and relay live data to researchers in a much more frequent timeline. In this study, a buoy equipped with a thermistor string and an EXO3 sonde (Yellow Springs Institute) was deployed to monitor for potential stratification and depleting lake bottom oxygen concentrations. This system measured water quality parameters and posted the data online every 20 minutes. Using these data, immediate vessel-based sampling trips to 7 sites were made according to observed hypoxia. Data captured show a hypoxic event occurred in the WBLE during early July 2020 that persisted for several days before being mixed by a storm on July 11, 2020. This hypoxic event coincided with 8 days of stratification. In addition, hypolimnion water warmed to over 23 ℃ while remaining stratified from the overlying waters, which could facilitate higher phosphorus flux from sediments. On average, phosphorus concentrations in the hypolimnion were 1.06 µ/L (~43%) higher than in the epilimnion by the end of the event, suggesting that sediments were releasing phosphorus into the overlying waters. Chapter 3: The western basin of Lake Erie (WBLE) has been experiencing Harmful Algal Blooms (HABs) for over a decade. These blooms have been detrimental to the health of Lake Erie and the safety of drinking water for surrounding communities. Nutrient inputs (namel (open full item for complete abstract)

Master of Science, University of Toledo, 2013, Geology

The four-dimensional surficial geology of Fulton County, Ohio is presented to elucidate the Late Pleistocene–Early Holocene deglacial history of the Huron-Erie Lake Plain. Ice-walled lake plains and the previously mapped lower Maumee strandline were evaluated in detail to help resolve controversies regarding their origins. High resolution light detecting and ranging imagery, ground penetrating radar, and electrical resistivity imaging allow rapid and accurate surveying of subtle topographic features in the flat till plains of NW Ohio where natural exposures of the stratigraphy are scarce. Optically stimulated luminescence dating (OSL) provides ages of sandy surficial sediments which often lack datable organics. Five terrains were mapped based on depositional environments: alluvial, eolian, glacial, glacial fluvial, and glacial lacustrine, which are characterized of various packages of sand, sand and gravel, pebbly sand, clay silt, and clay silt diamict. Two texturally distinct tills were identified and correlate to the Early and Late Woodfordian tills documented in other areas of the Huron-Erie Lake Plain. Nine OSL ages collected from sandy surficial sediments range from 19.4 ± 1.1 to 11.8 ± 0.6 ka providing some absolute age control and giving insight into the deglacial history. The oldest age of 19.4 ± 1.1 ka coincides with the Erie Interstadial and is older than the previously documented age of the Defiance Moraine. Auger borings of an ice-walled lake plain recovered interbedded sand and gravel underlain by clay diamict along its rim, while a resistivity survey imaged four inferred sediment types: lacustrine silt, clay diamicton, sand and gravel, and a loamy diamicton. Auger borings of another ice-walled lake plain only recovered diamicton. Both subglacial and supraglacial processes may explain ice-walled lake plain formation. The lower Maumee strandline mapped by Forsyth (1959) and Anderson (2011) has an elevation more consistent with the middle stand at (open full item for complete abstract)

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2024, English (Rhetoric and Writing) PhD

In 2019, The Lake Erie Bill of Rights (LEBOR) was voted onto the city charter of Toledo, Ohio. The charter amendment made it possible for citizens of the city of Toledo to sue polluters on behalf of the Lake, effectively giving Lake Erie more standing in court closer to that of legal personhood. A year later, LEBOR was deemed unenforceable by Judge Jack Zouhary, who critiqued it as vague and reaching too far beyond the jurisdiction of Toledo. This dissertation starts from those two critiques, analyzing how LEBOR fell short in 1. specifically connecting to the thousands of years of landscape practices and relations Indigenous residents had developed in the time before the region was colonized and 2. understanding the Lake as a place with a dynamic set of naturecultural relations with deep ties to the watershed and landscape within the jurisdiction of Toledo. This analysis uses theories from spatial rhetoric, placemaking, naturecultural critique, Indigenous scholarship, and postcolonial studies focused on the U.S. to understand why these shortcomings occurred and how future activist composers can possibly benefit from avoiding them. At the center of the analysis is an oral history composed using only the words of the activists in order to ground the work in their more immediate context. The dissertation concludes by evaluating how my analysis of LEBOR can be applied to teaching writing in and outside of the classroom and to scientific research projects that may otherwise be falling short in their connection with the public connected to the knowledge they gather and the organisms and entities they research.

Master of Science (MS), Bowling Green State University, 2020, Biological Sciences

Sandusky Bay and Lake Erie are plagued with harmful algal blooms every summer. Sandusky Bay is a drowned river mouth that is very shallow and turbid and is dominated by Planktothrix agardhii, while Lake Erie is dominated by Microcystis aeruginosa. Both species of cyanobacterium are non-diazotrophic and produce microcystin, a hepatotoxin. A competition experiment was conducted culturing both species alone and in coculture at nitrogen (nitrate) replete, nitrate restricted, and nitrogen-free environments. Planktothrix grew better alone at nitrogen restricted medium than in co-culture with Microcystis. In coculture, Microcystis was dominant over Planktothrix however, that dominance decreased as nitrogen was reduced in each treatment. In the nitrogen replete environment, the coculture produced significantly more toxin than the monocultures and in the no nitrogen environment the Planktothrix monoculture produced more toxin than the Microcystis monoculture or the coculture. The community composition in Sandusky Bay was monitored over the winter and spring months (January-April) to see how it changed as time progressed. Nutrient amendment experiments were also conducted adding nitrate, phosphate, and a combination of nitrate and phosphate to stimulate growth and identify any possible nutrient limitations. The initial community yielded low cell densities until the temperature increased and cell abundances followed shortly thereafter. Planktothrix dominated over the winter followed by a transitional period of cryptomonad and diatom dominations before transitioning back to Planktothrix. Both nitrate and phosphate were limiting Planktothrix growth in the spring, while nitrate alone was limiting the overall community.

Master of Science, The Ohio State University, 2017, Food, Agricultural and Biological Engineering

Lake Erie, among other inland waters, faces persistent threats from harmful algal blooms and hypoxia. The Western Lake Erie Basin (WLEB) algal bloom has especially been impacted by agricultural practices within its watershed; including the increased amount of surface field drainage in the heavy clays of the Paulding Plains. These shallow field ditches, 6 m wide, 0.5 m deep, and at least 100 m long, are too small to qualify under NRCS Conservation Practice Standard 412 for Grassed Waterways. Shallow field ditches are traditionally left unvegetated throughout the year, though sometimes grain crops are planted through them during growing season. It is hypothesized that these non-vegetated shallow field ditches are contributing statistically significant amounts of ammonium nitrogen (NH4-N), nitrate nitrogen (NO3-N), dissolved reactive phosphorus (DRP), total nitrogen (TN), total phosphorus (TP), and sediment to their respective sub-watersheds within the Maumee River watershed, the foremost contributor to WLEB. This thesis describes and assesses the effectiveness of an edge-of-field water quality monitoring strategy for surface runoff implemented at three paired sites in the Paulding Plains region. Each field location had a non-vegetated and vegetated shallow field ditch pair, each shallow field ditch was instrumented with an edge-of-field monitoring set-up. The vegetation comprised of Kentucky bluegrass, Kentucky 31 fescues, and perennial ryegrass mixture. Monitoring at the outlet of each shallow field iii ditch was conducted with a cutthroat flume and ISCO sampler programmed to water sample precipitation event discharges. The effectiveness of the edge-of-field surface runoff monitoring was assessed by investigating precipitation adjustment errors and the causes of researcher, instrument, no runoff, and negligible runoff errors at each site in the observed runoff and water sample collection data. Assessment of the edge-of-field set-up was also completed regarding the (open full item for complete abstract)

Master of Landscape Architecture, The Ohio State University, 2014, Architecture

This thesis considers Cleveland, Ohio's current and historic lakefront planning tradition through the lens of two land creation projects. The first, the Lake Erie International Jetport, was proposed in the late 1960s but never built. The second, the Cleveland Lakefront Nature Preserve, began its life in 1979 as a confined disposal facility for polluted sediments dredged from the Cuyahoga River and Cleveland Harbor. An examination of the motives, techniques, and desires behind these projects reveals that the creation of land from polluted dredged material is Cleveland's strongest and most consistent waterfront development tradition—one that has emerged from the distinct material economy of Cleveland to offer a future vision of the waterfront that synthesizes the city's industry, ecology, and culture.

Master of Science (MS), Bowling Green State University, 2024, Applied Geospatial Science

Wetlands are among the most productive ecosystems in the world, providing numerous benefits including supporting diverse plant and animal species, capturing/storing carbon, improving water quality, controlling floods, and cycling nutrients. Despite these benefits, wetlands have gradually been lost or degraded. Two of the world's largest inland freshwater systems, Lake Erie and Lake Victoria, have been negatively affected by Harmful Algal Blooms (HABs) and wetland losses, sparking wetland restoration projects in Lake Erie to limit potential HAB development. Yet, the greater danger from HABs is in Lake Victoria, where a lack of strong protection has put additional stress on wetlands. Wetland restoration, therefore, could serve as part of a solution towards Lake Victoria's algal blooms problem.The primary goal of this study was to perform wetland suitability analysis and identify general suitable lands or areas for wetland restoration projects in the Blanchard River Watershed that connects to Lake Eire and the Nyando River Watershed in the Lake Victoria region. This study used multi-criteria evaluation (MCE) for wetland suitability analysis, where criteria are represented by numeric weight of importance using Weighted Linear Combination (WLC). The weights were obtained from wetland restoration experts from the U.S Great Lakes region. The model was first tested in Blanchard River Watershed and then applied to the Nyando River Watershed. The resulting wetland restoration suitability model was rigorously tested with sensitivity analyses to evaluate the influence of various criterion weights. The results were broken into five classes and used to identify the most suitable areas for wetland restoration which were labeled as highest suitability areas. The results for the Blanchard River watershed show that 47.66% of the watershed has highest suitability for wetland restoration, while the comparable value for the Nyando River watershed had 10.64%. Sensitivity analysis using c (open full item for complete abstract)

Master of Science (MS), Bowling Green State University, 2023, Geology

In the last decades, the Western Lake Erie Basin (WLEB), USA, has been experiencing harmful algae bloom (HABs) events attributed to the large export of phosphate (PO4-3) and nitrate (NO3-) loads into waterways from farmland. There is current concern about exacerbating the HABs at the WLEB by discarding dredged materials (DM) in open lake waters. The State of Ohio has prohibited open lake water disposal, and it is requesting beneficial uses for the DM, and this study is exploring amending farm soil with DM. Previous research has demonstrated benefits on soil health when Hoytville soil was amended with DM from Toledo Harbor, OH, as the DM contains adequate soil organic matter (SOM) and calcium content. This study aimed to characterize the SOM in the DM by conducting a gentle chemical sequential extraction named Humeomics. Total organic carbon, total phosphorous, total nitrogen, and organic moieties associated with the SOM organo-soluble and hydro-soluble extracted fractions were characterized. Emission and excitation matrices were collected and paired with Parallel Factor analysis (PARAFAC) to characterize SOM fluorophores. The organo-soluble fractions exhibited terrestrial humic-like, terrestrial fulvic-like, and microbial tryptophan-like components. The hydro-soluble fractions showed microbial and humic-like and terrestrial or freshwater humic-like components. TOC concentrations in the organo-soluble and hydro-soluble fractions ranged from 594,022 to 483,723 mg kg-1 and 299,777 to 60,830 mg kg-1, respectively. Total phosphorus in the organo-soluble and hydro-soluble fractions ranged from 920.32 to 509.94 mg kg-1 and 31,389 to 182 mg kg-1, respectively. And total nitrogen in the organo-soluble and hydro-soluble fractions ranged from 11,614.47 to 2,879.86 mg kg-1 and 16,505.86 to 4,087.97 mg kg-1, respectively. Fourier-transform infrared spectroscopy analysis confirmed the presence of O-H (3400 cm-1), carbonyl (1720 cm-1), alcohol (3600-3000 cm-1), alkane (2915cm-1), (open full item for complete abstract)

Master of Science, The Ohio State University, 2023, Environmental Science

Anthropogenic impacts result in deteriorating drinking water source quality and the jeopardization of the environment and public health. The spread of antibiotic resistant (AR) bacteria and genes (ARGs) both clinically and in the environment, as well as the expansion of Cyanobacterial harmful algal blooms (cyanoHABs), have received attention for their impacts on public health. These two issues occur at the nexus of a changing climate. There is a need to address the combined impacts and interactions between these two historically independent issues in the environment. The possible role of Cyanobacteria in the environmental resistome should not be discounted. Many Cyanobacterial taxa have mobile and plastic genomes, account for massive proportions of freshwater biomass during cyanoHABs, and have been shown to possibly host ARGs. Viruses, particularly the phages that infect bacteria, are another emerging research topic linked to both issues. In the case of Cyanobacteria, Cyanophages are involved in the dynamics of cyanoHABs and are frequently suggested for use as Cyanobacterial biocontrols in controlled circumstances. In the case of AR, phages are studied as possible carriers of ARGs involved in the transduction of ARGs between bacteria. Therefore, research gaps relating to these issues and their co-occurrences are targeted in this thesis, which focused on two major drinking water sources from two historically cyanoHAB-impacted regions. One is Lake Erie, known for Microcystis-predominant cyanoHABs and the 2014 drinking water crisis. The other is Grand Lake St. Marys, known for persistent Planktothrix and high microcystin levels. In Chapter 1, a review is included referencing the current knowledge and literature on the topics and the two locations. In Chapter 2, the major objectives were to first monitor Cyanobacterial community trends in Lake Erie and GLSM drinking water sources and compare the two locations; second, to characterize the resistome in drinking water so (open full item for complete abstract)

MS, Kent State University, 2021, College of Arts and Sciences / Department of Earth Sciences

Glacial Lake Maumee (an early ancestor to Lake Erie) developed extensive beach ridges and bars that included an elongate arcuate bar complex at Columbus Grove, OH, that was very similar to the modern Presque Isle flying spit at Erie, PA, in terms of shape, its 10 km length, its shoreline orientation, and its angle from the coast, although it is extremely narrow, distally discontinuous, and extremely thin. The bars consist of relatively fine-grained, poorly sorted, polymodal sediment that has been extensively bioturbated and plowed, although their shapes are well preserved on the modern surface and they retain useful grain size signals regarding depositional processes and settings. Lake floor sediments are primarily very fine to medium silts with secondary clays and minor sands. Bars appear to have accreted in place, locally with lateral expansion but without significant migration or erosion. Vertical successions vary from cryptic upward shoaling and coarsening to quite heterogenous (better seen by extracting peaks rather than using basic descriptive statistics). Bars are thin (commonly <.5 - 1 m), and at least some begin with a marked shift from lake-floor silt to relatively well-developed sands, although rarely as coarse as sand peaks higher in the core. This suggests initiation by extreme waves touching bottom in relatively deep places, and thereby beginning construction of a sand pile that can benefit from progressively weaker waves as it grows upward. The arcuate shape of the bar complex is attributed to waves shoaling against an accretionary bulge in the coastline. However, until the bars start to connect and become continuous, longshore drift is not developed and lateral transport is prohibited, so bar segments grow individually from locally scavenged sand. This lake phase is thought to have been too short-lived to have permitted the bar to mature into a spit and become wide and complicated.

Doctor of Philosophy, The Ohio State University, 2020, Earth Sciences

Human activities including fertilizer application and fossil fuel burning have increased nutrient concentrations in coastal waters. Nutrient inputs can be difficult to constrain at the coastal interface where multiple waters mix, including river water, groundwater, and lake or ocean water. At coastal interfaces, rivers distribute their nutrient loads across delta wetlands, where processes like anaerobic respiration and plant uptake may reduce nutrient concentrations. Beneath the coast, groundwater also carries nutrients offshore, where biogeochemical reactions alter the nutrient chemistry and discharge rates are difficult to measure. I aim to improve the assessment of nutrient loads to coastal waters in these challenging environments through two case studies. First, I estimate groundwater discharge, a previously unaccounted source of nutrients, to the United States Great Lakes coast using high-resolution geospatial analysis. By integrating land use data, I also identify areas of the coast that are vulnerable to high nutrient loads from groundwater. My analysis shows that almost one-third of Lake Erie's United States coastline is vulnerable to contamination from groundwater nutrient sources. By collecting field measurements at a vulnerable beach site, I show that the nitrogen load from groundwater exceeds 1 gram/day/meter of coastline, which constitutes a small but non-negligible source to Lake Erie. In the second case study, I use benthic chambers to measure nitrogen removal rates in a coastal wetland in Wax Lake Delta, Louisiana. Results suggest that summertime nitrate removal kinetics are highly correlated with a widely available remotely-sensed vegetation index (NDVI). Heavily vegetated, submerged levees at intermediate elevations in the delta are thus predicted to be the most reactive habitats. Though less reactive, larger channels primarily on the eastern half of the delta may contribute most to nitrate removal, as they receive the greatest mass fluxes of nitra (open full item for complete abstract)

Master of Science (MS), Wright State University, 2019, Chemistry

Agricultural runoff poses a threat to the Wilmington, Ohio municipal water supply and its source waters. A harmful algal bloom (HAB) was documented in June 2019 in Caesar Creek Lake, Waynesville, Ohio. This study seeks to establish baseline nutrient concentrations in Caesar Creek Lake (Warren County, Ohio) and its tributaries, and to identify potential non-point sources of excess nitrogen and phosphorous that contributed to the HAB event. In collaboration with the Wilmington Water Department, dissolved inorganic nitrogen DIN-[N] (sum of NH3-[N], NH4+-[N], NO2--[N], NO3--[N] concentrations), dissolved phosphorous DP-[P], particulate phosphorous PP-[P], total phosphorous TP-[P] (total sum of DP-[P] and PP-[P] concentrations) and general water quality parameters were measured from May 30th, 2018 to the September 26th, 2019 in Caesar Creek Lake. Dissolved phosphorous DP-[P], particulate phosphorous PP-[P] and total phosphorous TP-[P] (total sum of DP-[P] and PP-[P] concentrations) concentrations were measured on January 23rd, 2019, and from April 9th, 2019 to September 26th, 2019. General water quality parameters, DP-[P] and DIN-[N] samples were taken at depths of 0, -2, -6, and -11 meters. Microcystin samples were obtained and analyzed concurrently by the Wilmington Water Department (WWD). Ion chromatography (IC) was used to determine nitrite, nitrate, and phosphate in water samples. Sediment samples were obtained from tributaries to Caesar Creek Lake and were analyzed for both TP-[P], DP-[P], and PP-[P] using inductively coupled plasma-optical emission spectrometry at 213.6 nm following acid digestion. A YSI Professional Plus electrochemical probe was used to measure general water quality parameters (dissolved oxygen, pH, temperature, specific conductance). The tributaries Turkey Run, Anderson Fork, and Buck Run had the highest measured inputs of DIN-[N] during the 2019 HAB event, with DIN-[N] concentrations of 6.58 mg/L, 3.74 mg/L, and 3.35 mg/L on June 5th, 2019. Hi (open full item for complete abstract)

MS, Kent State University, 2017, College of Arts and Sciences / Department of Biological Sciences

Polyamines, such as putrescine, play a vital role in marine dissolved organic nitrogen (DON) cycling, but their significance in freshwaters DON cycling has yet to be assessed. To address this knowledge gap, we examined the potential contribution of polyamine turnover rate to DON flux and the effect of dissolved polyamines on the composition of bacterioplankton communities in two freshwater lakes. To measure polyamine concentrations and turnover rates, water samples were collected in summer 2012 from 21 coastal-to-offshore transects along the southern coast of Lake Erie. A number of physicochemical variables and concentrations of polyamines and dissolved free amino acids were measured in water samples. Radioisotope assays were performed with whole (particle-associated bacterioplankton community) and filtered (free-living bacterioplankton community) lake water to estimate bacterial activity and turnover rates of polyamines. All five common polyamines were measured in each of the lake samples. Among the five PAs, putrescine and spermidine appeared to be the most abundant polyamine compounds. The ratio between dissolved free amino acid and polyamine concentrations were around 2:1. This was higher than the marine environments (1:10). The concentrations, turnover rates, and, fluxes of polyamines decreased from the western basin (eutrophic) to the central and eastern basins (oligotrophic). Each of these basins was consistently correlated with primary productivity of the lake. Additionally, the results also showed that putrescine alone accounted for 9.9% of the bacterial nitrogen demand and 4.8% of the bacterial carbon demand. All the above results indicate the importance of polyamines towards the DON cycling in the lake, similar to marine environments. To further evaluate the importance of polyamines for freshwater DON flux and examine the effects of exogenous polyamines on bacterioplankton community structure, water samples were taken from sites in Lake Erie (open full item for complete abstract)

Master of Science, The Ohio State University, 2016, Atmospheric Sciences

In this study, four key lake effect parameters were examined for 22 lake effect snowfall event case studies to the lee of Lake Erie from the period of 2007-2008 to 2015-2016. In addition, case study summaries were created to provide relevant background information. The case studies were broken down into that of 11 from Type I lake effect events and the remaining 11 from Type II lake effect events. The parameters studied include: lake induced instability, mean low-level wind flow, low-level relative humidity, and lake induced equilibrium level. Data for the parameters was extracted from the Penn State THREDDS Data Server in the form of RUC/RAP reanalysis data and then processed using a forecast profile visualization and analysis tool kit called BUFKIT. Reanalysis for the parameters was calculated on 3-hour intervals for the duration of the case studies and chosen for specific point locations across the surface of Lake Erie through the BUFKIT Data Distribution System. Type I case studies had three point locations or station identifications examined- LE1, LE2, and LE3, while Type II case studies had two point locations examined- LE1, LE2. The lake effect parameter data collected was then averaged over 6-hour intervals for each event and put in a table format. Complete event averages were also computed, charted, and put into table format. By doing so, an archive of key lake effect parameter values for past Type I and Type II events and the resulting snowfall amounts is available with the goal being to have created an analog system that can be used to help in the making of future lake effect snowfall forecasts. Type I and Type II complete event averages were then compiled and averaged for their corresponding band type. Once completed, trends in the lake effect parameters were observed and analyzed for statistical significance. Lake induced equilibrium level values as well as the height to which low-level relative humidity greater than or equal to 70% was (open full item for complete abstract)

MS, Kent State University, 2016, College of Arts and Sciences / Department of Biological Sciences

Through close interactions with biotic and abiotic environments, microbial communities in lakes mediate numerous biogeochemical processes that are essential in regional and global cycles of C, N and P. However, the relationship between bacterial community compositions and environmental conditions is still unclear. Lake Erie's natural gradient of nutrient supply and many other environmental parameters from the Sandusky Bay to the Central Basin provides an ideal experiment to examine how well bacterial community composition tracks environmental changes spatially and temporally. Surface water samples were collected along a transect that ran from the Sandusky Bay (hypereutrophic) via Sandusky Sub-basin (mesoeutrophic) to the Central Basin (oligotrophic) in June, July and August 2012. Zooplankton sample were also collected at each basin in June, July and August to see whether they respond to environmental conditions and to the changing bacterioplankton communities. Physico-chemical parameters were measured in situ. Bacterioplankton was collected on filters and filtrates were used for nutrient analyses, including ammonium, dissolved organic carbon, total dissolved nitrogen, nitrate, nitrite and soluble reactive phosphorus. Chlorophyll a concentration measurements confirmed the expected gradient of primary productivity among sites. Terminal restriction fragment length polymorphism (T-RFLP) analysis was conducted to compare of the microbial community structure and diversity along this natural gradient from the Sandusky Bay to the Central Basin. Additionally, zooplankton community structure and diversity was compared along the transect. Results showed that the free-living bacterioplankton structure differed significantly among sampling time, which was likely contributed by temporal variations in nutrient concentrations. As for the zooplankton community, Cyclopidae, Branchionidae and Synchaetidae were identified as major families (>78.4% of total zooplankton) in all samples. (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2007, Evolution, Ecology, and Organismal Biology

Herein, I describe research that quantifies how native and non-native (henceforth exotic) benthic organisms influence community and ecosystem processes. As aquatic ecosystems are recovering from years of excessive inputs of nutrients and industrial pollution, the influence of benthic food webs on the overall ecosystem likely will increase. By conducting a series of laboratory and outdoor experiments, observational studies, and field assessments in small reservoirs, I quantified how benthic organisms transfer material to higher trophic levels. For the native omnivore, gizzard shad Dorosoma cepedianum, growth and survival depended on the quality of sediment detritus, suggesting that detritus quality ultimately can regulate community and ecosystem productivity, mediated by its influence on gizzard shad biomass available for trophic transfer to piscivorous fish (Chapter 2). The addition of an exotic, benthic fish, round goby Neogobius melanostomusto the Lake Erie ecosystem, by being preferentially consumed over native prey by smallmouth bass Micropterus dolomieuappears to transfer benthic energy and contaminants to the pelagic food web (Chapter 3). A field study and historical data in Lake Erie revealed biomagnification of PCBs by an exotic species component (comprising round goby and dreissenid mussels Dreissenaspp.) to native terminal predators, smallmouth bass and largemouth bass Micropterus salmoides(Chapter 4). Recovering benthic macroinvertebrate communities in Lake Erie appear influenced by dreissenid mussels and dreissenid mussel interactions with PCBs and organic content of sediments (Chapter 5). As nutrient and contaminant inputs continue to decline and exotic species continue to proliferate, I predict an increase in the relative importance of such benthic transfer pathways in influencing variability in transfer of energy and contaminants from to the pelagic food web.

Master of Arts (MA), Ohio University, 2008, Geography (Arts and Sciences)

Lake-effect snowfall is a large contributor to yearly precipitation in the Great Lakes region, affecting the water budget as well as local economies. Air temperature is an important variable for lake-effect snowfall production, as it determines the temperature disparity that is needed between the water and the air. Recent increasing trends in air temperature have potential implications for lake-effect snowfall production. This thesis examines seasonal temperatures and lake-effect snowfall totals since 1950 for Cleveland, OH and Buffalo, NY to determine how seasonal temperature trends have affected yearly lake-effect snowfall outputs. Also, the effect of increased temperatures on snowfall patterns within winter seasons is analyzed. This provides a good case study for the examination of lake-effect snowfall with respect to air temperature and what might be expected in years to come. It was found that lake-effect snowfall will continue to increase until the mean winter temperature of a particular area rises above freezing.

Master of Science (MS), Bowling Green State University, 2012, Biological Sciences

In the past 100 years the nitrate levels in Lake Superior have increased more than five times (Sterner et al. 2007). Based on stable isotope assays, previous research has shown that most of this nitrate is coming from in-lake nitrification process in the lake (Finlay et al. 2007), reflecting an imbalanced nitrogen cycle. By contrast, in Lake Erie the nitrate levels are declining. Lake Erie is the shallowest of the Great Lakes. The shallowness of the lake, the warmer temperature of the water, and nutrient inputs from urban and agricultural sources make it most biologically productive of the Great lakes. Nitrification is a major process in the nitrogen cycle mainly carried out by the nitrifying microbial community (both Archaea and Bacteria), during which ammonia (NH3) is converted to Nitrite (NO2-) and then to nitrate (NO3-) by ammonia oxidizers (both Bacteria and Archaea) and Nitrite oxidizers (Bacteria only) respectively. Ammonia is oxidized by the enzyme ammonia monooxygenase, and hydroxylamine oxidoreductase (HAO). Nitrite (NO2-) converted to nitrate (NO3–) by Nitrite oxidizers (Bacteria) and enzyme nitrite oxidoreductase, carries this reaction. In this thesis, I investigated the microbial nitrifier community structure by identifying and enumerating the ammonia-oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) present in these two lakes using the technique of fluorescence in-situ hybridization (FISH). This is the first study on Lake Superior and Lake Erie proving the overview of the abundance and diversity of these organisms. This study is focusing on understanding the nitrifying microbial community structure, contribution to other studies dealing with how these organisms function in the nitrogen cycling in these lakes. Therefore, the goal of this study is to provide measure of abundance of AOB and NOB in Lake Superior and Lake Erie as well as the diversity of AOB in these lakes.

Master of Science, The Ohio State University, 1951, Graduate School

Master of Arts, The Ohio State University, 1961, Graduate School