Ecology and Evolutionary Biology Commons^™

Microplastic Composition And Exposure Pathways In Freshwater Systems: A Multi-Matrix Comparison Between Streams And Retention Ponds In Hamilton County, In, Mya Whaley

All-Inclusive List of Electronic Theses and Dissertations

Since the early 1900s, the use of plastics has increased exponentially. The breakdown of plastic materials has exposed all ecosystems to microplastics (small particles of plastic < 5 mm), which are now ubiquitous in natural settings. Microplastics have a relatively large surface area, and many chemicals adsorb to these small particles, impacting their fate and transport of pollution. While microplastics have been found in virtually every setting on Earth, research is necessary to understand their impact on freshwater ecosystems and biogeochemical cycles. The focus of this research was to investigate microplastic compositions in crayfish, sediments, and water samples collected in streams and retention ponds. We analyzed trends in microplastic counts across different land-cover classes, waterbody types, and species, and compared concentrations among matrices to improve our understanding of microplastic exposure pathways in freshwater ecosystems. As a secondary objective, lead and arsenic concentrations were analyzed from sediment samples to investigate metal burdens and compare them to microplastic concentrations. Our findings revealed that, in general, urban streams had the highest microplastic concentrations within land cover categories, and retention ponds had higher microplastic counts than streams. Crayfish, such as F. rusticus had higher microplastic concentrations than F. virilis and F. propinquus, although these results may be influenced by study design. The most common microplastic type was fibers, and most common color was transparent. There was no significant correlation between microplastic and metal concentrations in sediments. We found crayfish to be adequate bioindicators of microplastic pollution, because they were less impacted by environmental variability than sediment and water samples. This research presents the first evidence of microplastics in our study species, F. propinquus, F. rusticus, and F. virlis. This work presents new evidence of microplastic accumulation in crayfish, sediments, and water from freshwater systems in the Midwestern United States. Microplastics were found in every sample type—crayfish, water, and sediment—across urban, rural, and forested landscapes, highlighting their pervasive distribution. The findings provide foundational data for assessing emerging ecological and human-health risks and emphasize the importance of sustained monitoring and research on MP contamination in freshwater environments.

Quantifying Macrophyte Ecosystem Services And Improving Environmental Nonprofit Messaging, Peyton R. Hughey

All Theses

Environmental nonprofits are essential to the management and restoration of our natural spaces. They are also tasked with engaging the public via outreach, education, and advocacy. As natural spaces are degraded, the ability of environmental nonprofits to deliver on their missions will become increasingly important. This study aimed to improve two approaches to environmental nonprofits’ missions: ecological restoration and social media communication.

Environmental nonprofits operate with limited resources, and ecological restoration can be an exhaustive task; therefore, we explore functional restoration as a tool. In this study, we focus on the use of functional, trait-based restoration to restore ecological function …

Characterizing The Macroinvertebrate Community In Crissy Lake, An Impounded Reach Of The Pomme De Terre River, Prior To Channel Modification, Max Lundgren

Undergraduate Research Symposium (2026- )

The aging Crissy Lake Dam, on the Pomme de Terre River in Morris, has altered natural stream flow and impeded upstream passage of several fish species since 1939. In late 2026 the Minnesota Department of Natural Resources will replace the dam with stone arch rapids and facilitate river channel formation upstream of the dam. In order to evaluate the river modification project, we characterized the macroinvertebrate community in Crissy Lake, the impoundment upstream of the dam before implementation of channel modification. In September 2025 we collected benthic macroinvertebrates from two sets of Ekman grab samples. We found 12 taxa (average …

Brown Pelican (Pelecanus Occidentalis) Groundings On A Four-Lane Divided Highway In South Texas: A Comparative Study Using Citizen Science, Bradley Evan Beer, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Integrative Biological & Chemical Sciences Faculty Publications

The population of the once-endangered brown pelican (Pelecanus occidentalis) has increased over the past several decades and is now considered fully recovered. However, in south Texas, the combined effects of weather patterns, transportation infrastructure, and brown pelican biology have led to road mortalities on State Highway 48 (SH 48) at the Carl “Joe” Gayman Bridge. To mitigate these mortalities, the Texas Department of Transportation modified traffic barriers on SH 48. We aimed to examine the effect of the barrier change and determine which weather variables influence brown pelican groundings on SH 48. Citizen scientists monitored sections of SH …

Testing The Intermediate Disturbance Hypothesis On Anthropogenic Pressure In Central Alabama, Gavin Terrell

Theses

Biodiversity is fundamental to maintaining ecosystem structure and function globally. Prior to the late 20th century, ecological theory generally predicted that biodiversity would be highest in systems experiencing minimal disturbance. However, Joseph H. Connell challenged this view with the Intermediate Disturbance Hypothesis (IDH), which posits that species diversity peaks at intermediate levels of disturbance and declines under conditions of both low and high disturbance. Although widely cited, the applicability of the IDH to natural systems remains debated, particularly in the context of anthropogenic disturbances and when diversity is measured beyond species richness alone.

This study evaluated the predictions of the …

Enhancing Urban Garden Capacity By Linking Biodiversity And Ecosystem Function, Mary T. Nguyen, Carleen Rauh, Shelby Gresch, Charlotte Correiro, Heidi Elmendorf, Adriane Fugh-Berman, Gina Wimp, Alexandra L. Decandia

Virginia Journal of Science

Urban agriculture broadly describes food and plant cultivation in metropolitan areas. While biodiversity is thought to support ecosystem health and resilience, the relationship between above-ground and below-ground diversity has been understudied in urban green spaces. This study examines plant, animal, bacterial, and fungal diversity across three distinct urban habitats: a turf lawn, a forb garden, and a farming space. Using bacterial 16S rRNA and fungal ITS2 sequencing, soil nutrient analyses, and surveys of vegetation and wildlife, we connect diverse philosophies in urban agriculture to their role in advancing community diversity and ecosystem function. We found that different urban gardens support …

Raptor Abundance And Occupancy In Urban Parks Within Metropolitan Landscapes, Mary- Esther Leblanc

Posters - 2026

Rapid urbanization is one of the most significant and accelerating drivers of global biodiversity change, reshaping wildlife communities by fragmenting habitat, altering prey availability, and introducing human disturbances. Despite these pressures, some wildlife species are attracted to and may even flourish in urban settings, primarily because urbanization creates an altered landscape that often unintentionally provides resources functioning as components of habitat. (Chiron et al., 2024) Raptors, as apex predators within avian food webs, offer a valuable lens through which to examine these dynamics. While raptor communities are broadly negatively impacted by urbanization, some species can thrive in urban areas. (Leveau …

Bird Population Response To Abiotic And Biotic Stresses In Urban & Restored Oak Savannah Habitat, Annabelle Ball

Posters - 2026

Birds are heavily impacted by urban development. Many experience habitat fragmentation and removal of food sources. However, other species can adapt to and even thrive in urban environments, thanks to certain tree species, bird feeders, and buildings. In North America, the house sparrow and the European starling are invasive species that benefit from urban environments (Bartelt, 2011; Fitzwater, 2014). Meanwhile, many habitats across the continent are experiencing restoration/rewilding efforts for the benefit of birds. One such habitat is the oak-savannah, which is characterized by 10-30% canopy cover and a mixture of prairie & woodland vegetation, supporting a high diversity of …

Saved From The Brink Of Collapse: Evaluating The Success Of The Sussex Kelp Recovery Project, Keagan Farrell, Kelly Swyers, Adan Vasquez

Posters - 2026

Kelp forests are vital to ocean health, they provide habitat, food, and nursery grounds for a variety of marine species. These forests support fisheries, improve water quality, and help to protect coastlines (Eger et al. 2024). The Sussex Kelp Recovery Project is a marine conservation effort aimed at restoring their kelp forests along the Sussex coastline in southern England. This area lost up to 96% of its forests mainly due to the fishing practice trawling. Trawling is used to gather large amounts of fish, while dragging a net at the seafloor (Our history 2026). The main goal of the Sussex …

Analysis Of Traditional Wisdom For Ecological Sustainability In Tanzania: A Case Study Of Metaphorical Source Domains In Pangwa Ritual Texts, Winne Stephen Mtega, Angelus Mnenuka

Journal of Humanities and Social Sciences

Campaigns for ecological sustainability have gained a great currency in the contemporary academic discourse. Nonetheless, from time immemorial, Africans have pushed the ecological sustainability agenda through cultural taboos and regulated resource harvesting. Many African societies have embedded ecological consciousness in daily life expressions, and have intricately expressed it through literary and ritual texts. This study focuses on ecological awareness in the ritual texts of the Pangwa community. It analyses how environmental domains—such as land, seeds, and fruits—serve as the basis for metaphors in the Pangwa community to prove the use of wisdom to promote and sustain ecological practices (ecocriticism). The …

The Modern Sisyphus Blows Leaves: Attitudes And Impacts Regarding Leaf Litter Removal On A Suburban Campus, A. C. Nony, M. R. Mcclung, M. L. Reid

Journal of the Arkansas Academy of Science

Leaf litter habitat disruption in suburban spaces stems from the prevalence of “lawn culture,” that is, the accepted societal norm that land immediately surrounding humans or meant for human recreational use should be clean, tidy, controlled, and aesthetically pleasing, above other considerations. When leaf litter on residential and recreational lawns is cleared, it removes vital habitat for organisms of several taxa, especially species that rely on litter as a moisture and temperature-controlled substrate for overwintering. We administered an opinion survey to students, staff, and faculty at Hendrix College, a highly residential and suburban campus in Conway, Arkansas, to assess views …

Trophic Structure And Mercury Bioaccumulation In Walleye And Yellow Perch In The Upper And Lower Red Lake Basins, Marissa Pribyl

Biology Graduate Theses

Mercury is a persistent global contaminant that biomagnifies through aquatic food webs, with dietary and environmental factors serving as the primary drivers of accumulation in fishes. Trophic structure and methylmercury dynamics in Walleye (ogaa; Sander vitreus) and Yellow Perch (asaawens; Perca flavescens) were investigated in the Upper and Lower Red Lake basins in Red Lake, Minnesota, during 2024-2025. Diets of Walleye and Yellow Perch were assessed through stomach dissections, and tissue samples from both species were analyzed for total mercury concentrations. Additional analyses included shiners (gigoozens; Notropis spp., Hudsonius spp.) along with a variety of freshwater fish and …

Largemouth Bass Diet Changes Through The Summer In Central Minnesota, Ethan Kunz

Journal of Earth and Life Science

Largemouth Bass Micropterus nigricans is one of the most widespread fish species in the world, due in part to human introduction for angling. Largemouth Bass are opportunistic predators that will consume the largest prey they can often find; however, it has been shown that their diet mainly consists of invertebrates such as crayfish, with less focus on other fish species. This research aimed to determine what the Largemouth Bass diets in Central Minnesota consist of, and how they may change from the beginning of summer through the beginning of fall. A total of 174 Largemouth Bass were sampled from late …

Multi-Scale Drivers Of Beetle Biodiversity In A Rapidly Urbanizing Region, Alessandra Pandolfi

Graduate Studies Theses and Dissertations 2026

As cities continue to expand, designing urban landscapes that balance ecological resilience with biodiversity conservation has emerged as a pressing challenge. This dissertation examines urban ecosystems as complex and dynamic environments shaping plant and animal communities, with a particular focus on ground-dwelling beetles as ecologically significant indicators of environmental change. Conducted across the Orlando metropolitan area, one of the fastest-growing regions in the United States, this dissertation integrates experimental and observational approaches. Specifically, it aims to (1) test sustainable landscaping practices, (2) compare the ecological outcomes of conventional and alternative residential landscape designs, and (3) assess how gradients of urbanization …

Hfpo-Da Aquatic Toxicity And Bioaccumulation, Bailey Dawn Rappold

Theses, Dissertations and Capstones

Per- and polyfluoroalkyl substances (PFAS) have been detected globally in environmental media and biota. Legacy compounds PFOA and PFOS have been observed to be toxic and bioaccumulative in low doses and have been removed from production and industrial processes. Replacement PFAS chemicals are less understood and present a gap in current knowledge in their toxicological effects. This research utilized extended chronic toxicity studies to assess the impacts of HFPO-DA, a short chain replacement PFAS, on the standard aquatic toxicology organism Pimephales promelas. Organisms were exposed for 29 to 30 days at environmentally relevant concentrations of the toxicant, 7.8125 ng/L …

Soil Respiration Drivers And Challenges In A Changing Environment, Olivia Rae Haas

Theses, Dissertations and Culminating Projects

This study aims to understand post agricultural forested soils (sandy loam, silt loam, and loam) and the influences that drive carbon sequestration and soil respiration flux. Duke Farms in Hillsborough NJ, has historically been utilized as an agricultural zone for farming a variety of crops. Currently the area is protected with a focus on environmental conservation and restoration of the land. This includes getting a better understanding of the forested portions of the property. Understanding the quality of forested areas is vital as they have the potential to act as a carbon sink which can mitigate the effects of climate …

Impacts Of Native And Nonnative Plant Species On Avian Community Diversity, Matty John Mackay, Steven Van Dang, Brandon Lee Corn

SPARK Symposium Presentations

Avian communities play an essential role in maintaining a healthy ecosystem dynamic by regulating insect populations, assisting in plant pollination, and seed dispersal. These contribute to the overall health of natural ecosystems and mitigate ecological disruptions that would arise in their absence. However, the introduction of non-native invasive plant species can interrupt the balance avian communities bring to ecosystems by reducing availability of food sources, altering habitat structures, increasing competition among individuals, and disrupting ecological relationships through rapid invasion of ecological spaces. Point count observations of birds at Shelby Bottoms Park, Nashville, Tennessee in areas dominated by non-native privet and …

Evaluating Sampling Strategies To Monitor Southern Fox Squirrel (Sciurus Niger Niger) Populations, Casey Robin Hitchens

Theses, Dissertations and Capstones

Reliable population monitoring is essential for evaluating wildlife translocations and informing conservation management, yet traditional monitoring approaches are often labor intensive and require prolonged sampling. This study evaluated marking techniques, survey methods, and population estimation approaches for monitoring a translocated population of southern fox squirrels (Sciurus niger niger) at Marine Corps Recruit Depot Parris Island, South Carolina, USA (MCRDPI). From January-June 2023, I conducted six live trapping and camera trapping sessions across five survey sites. I compared the performance of color-coded collars and tail shaves for individual identification and the recapture probability between live traps and camera traps. Logistic mixed-effects …

End-To-End Modeling For The Ross Sea Region Marine Protected Area: A Review Of Available Tools For Conservation Objectives, James R. Lovvorn, Cara Nissen, Alexis A. Bahl, Erik Behrens, Cassandra M. Brooks, Katy Christensen, Michael S. Dinniman, Lilian A. Dove, Alice K. Duvivier, Eileen E. Hofmann, Hayley Kwasniewski, Young Shin Kwon, Sharon E. Stammerjohn, Lei Xing

CCPO Publications

The challenge of protecting marine ecosystems, including biodiversity and manifold interactions in changing environments, has encouraged development of end-to-end models linking physical drivers through entire food webs to upper-level predators. Ideally such models should have temporal and spatial resolution adequate to capture important small-scale processes, while including scales large enough to encompass local food webs and movements of wide-ranging consumers. The need for component submodels to be manipulated and upgraded independently by scientists from different disciplines, and used selectively depending on questions addressed, favors modular structure allowing linkage of different submodels with varying strengths and weaknesses. As an example, this …

Floodwater Salinity And Flood Duration Regulate Greenhouse Gas Production In High- Latitude Coastal Wetland And Tundra Soils, Mia J. Dicianna

Electronic Theses and Dissertations

Coastal high-latitude ecosystems are increasingly flooded from storm surges associated with climate change, exposing soils that were historically infrequently inundated to higher-salinity waters for longer durations. Sub-Arctic wetlands and tundra store large amounts of carbon, yet how flooding characteristics, particularly flood duration, influence microbial mineralization and, consequently, greenhouse gas (GHG) production in these soils remains poorly understood. We conducted a full-factorial microcosm incubation experiment in which coastal wetland and tundra soils were subjected to simulated flooding with three durations (1, 3, and 10 days) and four salinity treatments (unflooded, freshwater, 3 ppt, and 12 ppt) and measured carbon dioxide (CO2) …

Does Fishery Management For Groupers (Teleostei: Epinephelidae) Protect Them Effectively? Context From The Iucn's Red List Of Threatened Species, Sean T. Fennessy, Christi Linardich, Kevin Rhodes, Joao P. Barreiros, David Pollard, Eloy Sosa-Cordero, Felicia Coleman, Alfonso Aguilar-Perera, Christopher R. Malinowski, Thierry Brulé, Pedro Afonso, Kayan Ma, Min Liu, Muktha Menon, Colin Wen, Stanley K. H. Shea, Sean N. Porter, Matthew Craig, Yvonne Sadovy De Mitcheson

Biological Sciences Faculty Publications

Worldwide, groupers (Epinephelidae) are commercially valued fishes, which also play key ecological roles on tropical and subtropical reefs. In 2007 and 2016, the IUCN's Groupers and Wrasses Specialist Group assessed all 160+ grouper species, with 17 of these being identified as threatened in 2016 and the major threat factor being overexploitation. Our present study aimed to identify whether management measures (MMs) for previously assessed groupers were established, whether these measures aligned with IUCN's Red List categories, and whether they effectively protect grouper populations. Experts in grouper biology and management assigned scores per grouper species based on the extent to which …

Using Camera-Based Unmarked Spatial Capture-Recapture Modeling To Estimate Reintroduced Elk (Cervus Canadensis) Population Parameters And Distribution In Southeastern Kentucky, Claire Marie Muia

Theses and Dissertations--Forestry and Natural Resources

Estimation of population parameters is important for wildlife management decisions. Elk reintroduced to southeastern Kentucky experienced early irruptive population growth and are currently monitored using a statewide harvest-based statistical population reconstruction model (SPR) across the Kentucky Elk Restoration Zone (KERZ). Because the SPR model is spatially coarse and difficult to scale to the smaller management units comprising the KERZ, we conducted a spatially explicit capture-recapture study using a clustered camera-trapping array deployed for 10 weeks from June–August 2024 to estimate elk population parameters within Management Unit 4. Due to a lack of resights of GPS-marked elk, population parameters were estimated …

Effectiveness Of Walleye Stocking In Winter Kill Lakes, Tyler Haus

Journal of Earth and Life Science

Winter kill events, marked by extensive fish mortality due to hypoxic conditions under the ice, are a common phenomenon in shallow eutrophic lakes, especially in the northern lakes in the northern United States. These events can drastically alter fish communities and often result in the elimination of top predators. Though these lakes will typically slowly bounce back to what they were in a couple of years. This study evaluates the effectiveness of walleye, Sander vitreus, stocking in lakes after a winter kill. For this study, four known winter kill lakes that are consistently stocked with walleye were studied. Pre- …

Assessing Urban–Rural Differences In Largemouth Bass Abundance In Minnesota, Jonathan Gates

Journal of Earth and Life Science

Urbanization can significantly alter freshwater ecosystems and influence sport fish populations. This study examined differences in largemouth bass Micropterus nigricans catch-per-unit-effort (CPUE) between urban and rural lakes in Minnesota and evaluated temporal changes between 2000–2010 and 2011–2021. Forty lakes (20 urban, 20 rural) were selected using Minnesota Department of Natural Resources fisheries survey data. Lakes were classified using NLCD 2019 land cover data, with ≥10% developed land designated as urban. Nonparametric analyses (Wilcoxon rank-sum and signed-rank tests) were used to assess spatial and temporal differences in CPUE. Results showed that rural lakes had consistently higher median CPUE than urban lakes …

Neonicotinoid Bioaccumulation In Bluegill And Bullhead Within Lake Julia And Lake Zumwalde, Jake Stuber

Journal of Earth and Life Science

Brown Bullhead Ameiurus nebulosus, Yellow Bullhead Ameiurus natalis, and Bluegill Lepomis macrochirus are unique in their stark differences. Bullhead are scaleless bottom feeders that can tolerate high pollution and low O₂ conditions. In contrast, Bluegill are scaled, aggressive nesters and are less tolerant of high pollutants or low-oxygen conditions. Among these pollutants include a class of chemicals called neonicotinoids (hereafter referred to as neonics). Neonics are a class of insecticides primarily used within agriculture and pest management. Due to the effectiveness, application has escalated on a global scale. They have been well documented by many toxicology assessments. …

Indigenous Land Seizure & Environmental Injustice: Impacts Of Settler Colonialism, Lydia Moorman

Journal of Earth and Life Science

The fields of conservation and environmentalism prioritize ecosystem health, yet both emerged from western frameworks that displaced and criminalized Indigenous land stewardship. The idealization of “pristine wilderness” narratives served to justify the removal of Indigenous peoples from their homelands and erased millennia of sustainable land stewardship that had maintained ecological balance long before western conservation existed. These narratives not only misrepresented Indigenous relationship with land but also constructed a false dichotomy between humans and nature that positioned Indigenous presence as a threat rather than a source of ecological knowledge. Simultaneously, anthropogenic expansion; such as pipelines, mining, railroads, and other extractive …

Ovipositional Behavior Of The Twig Girdler (Cerambycidae: Oncideres Cingulata) On Stems Of Mockernut Hickory (Carya Tomentosa) In Arkansas, R. Tumlison, L. Serviss

Journal of the Arkansas Academy of Science

The Twig Girdler (Cerambycidae: Oncideres cingulata) is a long-horned beetle that girdles stems of certain species of trees to prepare a habitat for its offspring. The stems eventually die, break, and fall from the tree, but the beetle usually had already laid its eggs within the stems. Eggs are laid singly, almost always at growth rings or leaf bases. Because the space for the young to develop is finite, laying too many eggs could cause reproductive failure and too few eggs would be suboptimal. We hypothesized that the female laying eggs should be able to evaluate the stem and …

Western Massasauga (Sistrurus Tergeminus): A Species Conservation Assessment For The Nebraska Natural Legacy Project, Colleen Rothe-Groleau, Melissa J. Panella

Nebraska Game and Parks Commission: Publications

The Nebraska Natural Legacy Project recognizes the western massasauga (Sistrurus tergeminus) as a Tier I at-risk species. Provided are some general management recommendations regarding western massasaugas. Conservation practitioners will need to use professional judgment to make specific management decisions based on objectives, location, and a multitude of variables. This resource was designed to share available knowledge of this at-risk species that will aid in the decision-making process or in identifying research needs to benefit the species.

Criteria for selection as Tier I: State listed, G3

Estimated Population in NE: 1,000–2,500

Estimate based on: Field surveys

Trends since 2005 …

High Algal Biomass Is Decoupled From Metabolism In The Gallatin River, Cora Mae Steinbach

Graduate Student Theses, Dissertations, & Professional Papers

Assessing eutrophication in rivers is difficult compared to lakes and coastal waters, because most algal biomass occurs on the riverbed and flows interact and co-vary with production (Biggs and Close, 1989; Bernhardt et al., 2018). Riverine eutrophication is typically assessed using algal biomass and water column nutrients (U.S. Environmental Protection Agency, 2000), but biomass is highly variable and labor-intensive to measure, while nutrient concentrations often underestimate enrichment due to rapid biological uptake (Dodds and Smith, 2016). Reach-scale river metabolism can help evaluate long-term functional change in rivers recovering from nutrient enrichment (Arroita et al., 2019; Jankowski et al., 2021; Diamond …

The Sub-Lethal Effects Of Trematode Parasites On The Migratory Behavior Of Lesser Scaup (Aythya Affinis), Scott Alan Herman

Graduate Research Theses & Dissertations

The introduction of the invasive freshwater faucet snail (Bithynia tentaculata) and its associated parasites in the Upper Mississippi River and Great Lakes Region provides the opportunity to investigate how anthropogenic stressors impact the life history of lesser scaup (Aythya affinis) using the Mississippi Flyway. To understand the life histories and interactions between lesser scaup and faucet snails we examined historical records, research, and ecology textbooks. Our literature review identified critical knowledge gaps in lesser scaup literature surrounding population dynamics, reproduction, and migration. Specifically, the sub-lethal effects of invasive trematodes on the migratory behavior of lesser scaup in the Upper Mississippi …