Digital Commons Network^™

Unveiling Microplastic Removal And Characteristics In Wastewater From Two Municipal Wastewater Treatment Facilities In Indonesia, Nurul Setiadewi, Prayatni Soewondo, Cynthia Henny

Applied Environmental Research

Wastewater treatment plants (WWTPs) are considered an entrance pathways for microplastic (MP) pollution in aquatic environments. This study reveals the removal and characteristics of MPs in wastewater from two municipal WWTPs in Indonesia. The influent contained 17.1 ± 5.65 particles L-1 (WWTP A) and 15.45 ± 4.31 particles L-1 (WWTP B), whereas the effluent contained 1.41 ± 0.01 and 1.5 ± 0.16 particles L-1. The removal efficiency was 91.75% for WWTP A and 90.32% for WWTP B, with no statistically significant difference (p > 0.05). WWTP A employed advanced treatment units, whereas WWTP B used a conventional pond-based system. MPs were …

Assessment Of The Influence Of Human Activities On The Occurrence Of Forest Fires In Thailand Via Multiple Linear Regression (Mlr), Sittipong Ruktamatakul, Jirarat Insuk, Benjaporn Pinwongpet, Sarisa Ruktametakul, Pornpis Yimprayoon

Applied Environmental Research

Forest fires represent one of the most critical environmental challenges in Thailand, with impacts varying depending on forest type, fuel characteristics, terrain conditions, fire intensity, and the frequency of fire occurrence on the same landscape. While forest fires can contribute to ecosystem degradation, biodiversity loss, and the depletion of natural resources, such effects are not uniformly severe across all forest ecosystems. Understanding the human-induced factors contributing to forest fire occurrence is crucial for developing effective prevention strategies and promoting sustainable forest management. This study aimed to identify the anthropogenic factors influencing forest fire areas in Thailand via multiple linear regression …

Effect Of Chromium Doping On The Uv- And Sunlight-Driven Photocatalytic Performance Of Srtio3, Ro’Ikhatul Jannah, Dianisa Khoirum Sandi, Fahru Nurosyid, Risa Suryana, Didier Fasquelle, Yofentina Iriani

Applied Environmental Research

Chromium (Cr)-doped strontium titanate (SrTiO3, STO) photocatalysts with compositions of SrTi1-xCrxO3 (x = 0, 5, and 10%) were prepared via the coprecipitation method. This study aimed to investigate the effects of Cr doping on structural, morphological, and optical properties. Furthermore, this work aimed to examine the photocatalytic performance of pure and Cr-doped STO against methylene blue (MB) degradation under ultraviolet (UV) and sunlight exposure. X-ray diffraction confirmed the formation of the cubic STO phase and the insertion of the Cr dopant in the STO structures. Furthermore, Cr doping reduced the lattice constant, crystallite size, and average particle size and narrowed …

Spatial Temporal Modeling Of Infectious Disease Patterns In Texas, Robert E. Lashbrook

Earth & Environmental Sciences Theses

The Texas Department of State Health Services monitors numerous notifiable conditions statewide, including Campylobacter, Salmonella, Shiga toxin-producing Escherichia coli (STEC), Rabies, and West Nile virus (WNV). Given the substantial health, economic, and public health burden associated with these conditions, improving prediction is an important step toward reducing their overall impact. This study evaluated whether external demographic, social, climate, and environmental data could improve prediction of county-year disease activity across Texas. County level data was analyzed using supervised machine learning models, including linear regression, ridge regression, multilayer perceptron, random forest, XGBoost, as well as K-means clustering to identify broader …

Changing Snow Hydrology In The Great Lakes And Resilience Through Adaptive Management, Aradea R. Hakim

Dissertations, Master's Theses and Master's Reports

A number of studies have found that global snow cover is generally decreasing, but a closer examination at regional scales shows greater complexity. In the Great Lakes basin, contrasting trends have been identified. While snow cover is generally decreasing basinwide, leeward (downwind) regions have experienced increases in snowfall and snow cover. Changes in snow dynamics are also associated with shifts in runoff timing and volume due to earlier snowmelt and changing precipitation patterns. Streamflow analyses at gauges across the Great Lakes basin indicate trends toward earlier peak runoff and longer runoff periods, although these patterns vary among watersheds and lake …

Evaluating Quahog (Mercenaria Mercenaria) Nursery Methods And Production Costs To Support Diversification Of Maine’S Fisheries And Aquaculture Sector, Hannah G. Wolf

Honors Theses

Populations of wild and farmed quahogs in Maine are expanding, driven by warming waters, declining soft-shell clam populations, and the need to diversify fisheries. The Northern quahog (Mercenaria mercenaria) is a potential species to diversify Maine’s marine sector, as its geographical range is expanding, and they appear more resistant to green crab predation. Enhancing wild quahog stock provides economic and social advantages for both the aquaculture and wild harvest industries. However, there is limited understanding about the commercial viability of producing quahog seed on existing farms for wild shellfish enhancement in Maine. This research, part of a larger NOAA …

A Framework For Evaluating Riparian Climate Refugia In The Eel River Watershed, California, Farrah Tyler

Cal Poly Humboldt theses and projects

Climate change is increasing the need to identify and protect landscapes that support biodiversity through both habitat connectivity and climate refugia. Climate refugia are areas that remain relatively buffered from regional climatic change, enabling species to persist despite shifting environmental conditions. Riparian ecosystems can function as both movement corridors and climate refugia, yet methods for identifying these features and understanding the environmental processes that sustain them remain limited. In California's North Coast region, the identification and conservation of watersheds that may serve as climate refugia for sensitive plant and animal species will be essential for long-term ecosystem management and conservation. …

Development Of The Core Lit Apparatus For Seaweed Hatcheries (Clash) Bioreactor Using A Germplasm Approach, Phillip O. Tahimic

Cal Poly Humboldt theses and projects

In comparison to the Asian aquaculture industry, the United States has minimal seaweed production. There are several drivers of the limited industry in the US, such as regulatory constraints and limited market demand, but the ability to scale is a considerable barrier to commercialization. One possible solution is the development of land-based systems that integrate bioreactors, which utilize fewer resources and do not wholly rely on an oceanic flow-through system. This study assessed the application of a modular bioreactor, known as Core Lit Apparatus for Seaweed Hatcheries (CLASH), as a nursery system and open-source project designed to expand land-based seaweed …

Land Cover Classification Using Optimized Imagery Resolution And Machine Learning Algorithms For A Long-Term Monitoring And Restoration Project, Jessica R. Suoja

Cal Poly Humboldt theses and projects

Ecosystem services and functions are prone to water resource exploitation resulting in cascading effects that include decrease of biodiversity and loss of riparian vegetation, a keystone habitat in desert riparian ecosystems. Mono Lake is a prime example of overexploitation of water resources leading to legal action and eventually a legally mandated long-term monitoring and restoration project. Monitoring and restoration projects can benefit from techniques such as remote sensing and machine learning algorithms to generate accurate land cover classification maps for calculating land cover change over time. However, the spatial resolution of remote sensing imagery and the machine learning algorithms chosen …

Contribution Of Lagoon-Rearing Juvenile Chinook Salmon (Oncorhynchus Tshawytscha) To The Adult Spawning Population In The Mattole River, Emma Held

Cal Poly Humboldt theses and projects

Bar-built estuaries are rivermouth confluences characterized by periods of disconnection between the river and the ocean due to a sandbar that builds across the mouth. Sandbar timing characteristics vary between years and between systems, but when closed, a lake-like lagoon forms in the estuary footprint. The Mattole River has a bar-built estuary that forms in late spring or early summer, often overlapping with juvenile Chinook salmon outmigration. Juveniles that do not leave the river before the bar closes must remain in the lagoon until the mouth opens in fall. The purpose of this thesis was to understand if lagoon-rearing is …

Factors Influencing Tree Vigor And Structural Failure Along Powerline Corridors In Northern California: A Multi-Species Analysis, David Justin Dorval

Cal Poly Humboldt theses and projects

Tree failures (e.g., stem breakage, uprooting, or branch drop) can pose significant risks to public safety, particularly along powerline corridors for the risk of power outages and wildfire ignitions. In California, tree-related powerline failures have led to severe ecological and human costs in recent years. Despite extensive research on tree failure in urban environments and post-disturbance contexts, comparatively little empirical work has examined where powerlines intersect largely unmanaged stands. This study evaluates tree failure trends across multiple forest types in Northern California by examining how tree-level characteristics influence recent growth and failure occurrence in regionally dominant tree species. Specifically, the …

Ammonia Synthesis By Nanosecond Pulsed Atmospheric Pressure Plasma Jets Impinging On Water, Zach Caudell, Lynnet Rich, Olga Pakhomova, Chunqi Jiang

Bioelectrics Publications

Developing energy-efficient technologies for carbon-neutral ammonia (NH₃) synthesis is critical for decentralized fertilizer production and global decarbonization. This study investigates generating NH₃ from water using a nanosecond pulsed atmospheric pressure plasma jet (ns‑APPJ) operating in either N₂ or dry air. The plasma jet reactor employed approximately 250 ns, up-to-22 kV pulses at 500 Hz to sustain a nonequilibrium discharge impinging directly on static liquid water. The kinetics, energy efficiency, and product selectivity of NH3 formation were quantified as functions of the pulse voltage, repetition frequency (PRF), and gas flow rate. NH₃ production increased linearly with treatment time and scaled strongly …

Early Successional Response To Stream Daylighting In Redwood National And State Parks, Orick, California, Rylee Rawson

Cal Poly Humboldt theses and projects

In-channel stream restoration projects can act as both disturbance and recovery mechanisms, disrupting existing conditions to reestablish the hydrologic and ecological processes that sustain stream ecosystems. These interventions initiate successional trajectories in which channel form and biological communities reorganize over time. In Redwood National and State Parks (California, USA), the Redwoods Rising initiative restores buried headwater channels by recontouring legacy logging roads and daylighting streams buried by Humboldt crossings. Using the National Park Service Klamath Network wadable stream monitoring protocol, I evaluated nine restored reaches spanning one to five years post-restoration, alongside old-growth reference reaches and available pre-treatment data. I …

Assessing Water Storage In Northern California Forests, Christopher Gerard Gressierer

Cal Poly Humboldt theses and projects

The climate is changing, with rising temperatures projected to increase vegetation stress and mortality. Precipitation is also expected to become more extreme, with longer dry seasons intensifying droughts, and wetter wet seasons increasing the risk of landslides or floods. Summer baseflows in northern California are declining, and a shift in water availability may alter vegetation communities, resulting in mortality and species composition changes. These trends highlight the need for increased attention and management to be focused on evaluating and maintaining watershed water storage to maintain ecosystem health.

This study estimates water storage capacity using a water balance approach, drawing in …

"What Power Do We Have?" Community Capacity And Justice In Samoa, California’S Floating Offshore Wind Terminal Development, Lauren Mccall Hart

Cal Poly Humboldt theses and projects

Floating offshore wind (OSW) is a relatively novel technology in the United States, which is positioned to play an integral role in California’s decarbonization strategy. Two federal OSW lease areas have been established off the coast of Northern California, and plans are underway to develop supporting port infrastructure, including the Humboldt Bay Offshore Wind Heavy Lift Marine Terminal (HLMT). The proposed HLMT site is adjacent to communities on the Samoa Peninsula of Humboldt Bay, which currently face socio-environmental vulnerabilities and critical infrastructure gaps. The social implications of OSW port development remain poorly understood, particularly in rural and underserved communities. This …

Chesapeake Bay Water Clarity: Challenges And Successes, Jessica S. Turner, Carl T. Friedrichs, David B. Parrish, Kelsey A. Fall

OES Faculty Publications

The Chesapeake Bay is a large estuarine system spanning multiple jurisdictions and serves as a model for estuarine health worldwide. Historically, nutrient loading degraded water quality, prompting the need for regulation. Water clarity, one component of water quality, is vital for benthic communities and serves as a key indicator of overall ecosystem health. Here, physical resuspension and salinity gradients, nutrient and sediment inputs, production of organic detritus by phytoplankton, and benthic communities all interact to drive clarity patterns, with high spatial variability. Trends over the last 50 years show improvement, though with a temporary increase in organic detritus in response …

Contribution Of Non-Linear Internal Waves To Marine Net Primary Production Has Been Underestimated, Xiaoju Pan, Tung-Yuan Ho, George T. F. Wong, Jen-Hua Tai, Shoude Guan, Fuh-Kuo Shiah

OES Faculty Publications

Field observations in the northern South China Sea (NSCS) indicate that elevated concentrations of chlorophyll a (Chl_a) associated with non-linear internal waves (NIWs) were more pronounced in the subsurface than at the sea-surface. At a given surface Chl_a, the vertically integrated Chl_a in an NIW-active area was 45% higher than that in an area where the NIW activities were minimal. As a result, net primary production (PP_eu) estimated from surface Chl_a from remote sensing by using the current Chl_a-based PP_eu model (e.g. VGPM) would have underestimated the true value by the same amount. If this correction is …

Unintended Consequences Of Estuarine Management Within The Trajectory Of Recovery: Examples From The Chesapeake Bay, Jessica S. Turner, Fei Da, Molly M. Mitchell

OES Faculty Publications

Estuaries are vital ecosystems that support biodiversity, human populations, and economic activities such as fisheries, aquaculture, and tourism. Managing estuarine systems often involves interventions to regulate sediment and nutrient inputs with the goal of improving water quality, and subsequently the economic values of the estuary. However, these management strategies can produce unintended consequences. The Chesapeake Bay is an estuary recovering from eutrophication which provides clear case studies for these patterns. In the Chesapeake Bay, decreased sediment inputs, resulting from shoreline stabilization and watershed modifications, can impair marsh resilience to sea level rise and disrupt sediment-light-algal interactions affecting water clarity. Likewise, …

Uncertainty-Aware Estimation, Planning, And Control For Tracking Multiple Drifting Patches In Flow Fields, Daniel O. Akanji, Krishnanand N. Kaipa, Cong Wei

Mechanical & Aerospace Engineering Faculty Publications

In this study, we present a replay-based framework for uncertainty-aware persistent tracking of multiple advected surface patches using an autonomous marine vehicle operating in spatiotemporal-varying currents. The method combines three components: local flow estimation, covariance-aware patch-boundary propagation with intermittent boundary fusion, and mission-level scheduling over multiple patches. Each patch is represented by a polygonal boundary, whose vertices are propagated through the estimated flow field while carrying per-vertex covariance, thereby quantifying uncertainty growth during advection. A flow-aware gain-scheduled linear quadratic regulator (LQR) was designed to shape the desired surge speed to take advantage of favorable currents. When the vehicle services a …

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 …

Triangulating Primary Sources, Professional Judgement, And Llm-Generated Summaries: Educating Nurses In An Ai-First World, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Urban Trees In The Urban Hydrology Cycle, Jorge R. Vera

Theses, Dissertations and Capstones

In urban forestry, trees provide numerous economic, ecological, and aesthetic benefits to the surrounding community. One of their key roles is intercepting stormwater runoff, reducing flooding risk, and improving water quality. Chapter 1 of this thesis characterized the ecological and economic contributions of urban trees on the Marshall University campus and provides guidance on their management and conservation in the future. Chapter 2 examined how urban tree species modify the urban hydrology cycle by altering the volume and timing of precipitation delivery. In Chapter 1, we inventoried 114 acres of Marshall University's main campus in Huntington, WV, from June 28 …

Greenhouse Gas Report For Western Australian Wild-Catch Fisheries And Aquaculture 2004-2025, Christophe D'Abbadie, Johnny Machon, Dipesh Maharjan, Mark Goninon, Pia Dobson, Jason How, Rodney Duffy Dr., Ainslie Denham, Shaye Carman, Trina Anderson

Climate Science Published Reports

This report provides a comprehensive analysis of greenhouse gas (GHG) emissions from Western Australian wild-catch fisheries and aquaculture for the fiscal years (FY) 2004/05 to 2024/25. These industries represent important components of the Western Australian primary production sector, with distinct emissions profiles and trends.

Key Findings:

Emissions from wild-catch fisheries have declined significantly over time, from approximately 0.341 million tonnes of carbon dioxide equivalent (Mt CO₂e) in FY 2004/05 to 0.136 Mt CO₂e in FY 2024/25, a reduction of approximately 60%.

Emissions from aquaculture in FY 2024/25 were approximately 0.350 Mt CO₂e, reflecting substantial industry growth from near-negligible levels in …

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 …

Equity In Coastal Resilience: A Framework For University Engagement In Community-Based Projects, Juita-Elena (Wie) Yusuf, Jennifer L. Whytlaw, Marina Saitgalina, Ogechukwu N. Nwandu-Vincent, Khairul A. Anuar, Thomas Allen, Joshua Behr

School of Public Service Faculty Publications

As communities face intensifying climate hazards, it is vital to strengthen resilience in ways that explicitly prioritize social equity. This study examines how higher education institutions can better support government, nonprofit, and community partners in advancing equity-centered coastal resilience in the U.S. Utilizing a qualitative research design, we analyze discussions among researchers and practitioners during a three-day workshop. We present a framework derived from a thematic analysis of breakout group transcripts from a three-day national virtual workshop involving 113 researchers and practitioners. The analysis identified four core themes: the necessity of aligning projects with community-defined priorities; the foundational role of …

Assessing Radio Transmitter Weight Effect And Evaluation Of Northern Bobwhite Chick Survival In Coastal North Carolina, Autumn S. Randall, Theron M. Terhune Ii, Matthew T. Springer, Darin J. Mcneil

Forestry and Natural Resources Faculty Publications

Studies on the earliest life stages are essential to our ecological understanding of avian demography; however, monitoring technologies that allow tracking of small birds are still limited in a variety of ways. One critical limitation, until recently, has been the development of methods for attaching transmitters to young birds with precocial development (e.g., Galliformes, Charadriiformes, etc.). The modified suture technique offers a means to attach transmitters to precocial chicks while accommodating rapid growth characterized by birds with precocial young. Although the sutured transmitter method was developed for northern bobwhite (Colinus virginianus) chicks, there remain key unknowns regarding best …

Aggregation Bias In Multi-Industry Economic Contribution Analysis: The Case Of Kentucky Forest Sector, Domena A. Agyeman, Thomas Ochuodho, Omkar Joshi

Forestry and Natural Resources Faculty Publications

Closely related industries are often aggregated in US forest sector economic contribution analysis, yet the choice of aggregation scheme can influence results. The Impact Analysis for Planning (IMPLAN) system is the most widely applied input–output model for forest economic contribution analysis in the US. In IMPLAN, the level of industry aggregation determines which inter-industry transactions are restricted, thereby influencing the magnitude of estimated indirect and induced effects. Although IMPLAN practitioners can model individual industries to avoid aggregation bias, they must still decide whether to analyze forest industries as a single group, as traditional subsectors, or individually. This decision can alter …

Effects Of Headwater Wetland Restoration On The Demography, Fecundity And Ecology Of The U.S. Federally Threatened White Fringeless Orchid (Platanthera Integrilabia) In The Cumberland Plateau Of Kentucky, Tara R. Littlefield, Catherine Hoy, Christopher Barton

Forestry and Natural Resources Faculty Publications

Wetland habitats represent a critical component of biodiversity hotspots that support numerous rare species, including terrestrial orchids. In North America, over half of all terrestrial orchids are found in wetlands, more than a quarter of which are now threatened with extinction (G1–G3). This concerning trend is exacerbated by a lack of information on effective restoration strategies aimed at orchids and other species that inhabit these areas. The white fringeless orchid, Platanthera integrilabia (Correll) Luer, the subject of this study, is restricted to mostly shaded wetland habitats along the Cumberland Plateau of the Appalachian Mountains and has suffered widespread declines due …

Below The Rows, Beyond The Roots: An Art Exhibition Depicting Agriculture Across The Globe, Maggie Enoch

Honors Theses and Capstones

In Below the Rows, Beyond the Roots, artist Maggie Enoch creates multimedia works inspired by her exposure to diverse agricultural systems and perspectives while studying geography and sustainable agriculture/food systems around the world. By integrating complex histories with the contemporary realities of farming, Maggie paints vivid pictures of the power of food in this five-piece exhibition.

Summary Of Beaver And Iron Counties’ Water Conservation And Provisioning Strategies, Lisa Welsh, Joanna Endter-Wada, Burdette Barker, Bethany Neilson, Anna Mcentire, Melissa Stamp, Brian Steed

Reports

This report focuses on water conservation and provisioning strategies that both Beaver and Iron Counties are pursuing to help meet their citizens’ current and future water needs and to contribute to statewide water conservation efforts. It primarily relies on publicly available data from state, county, conservancy district, and city databases, plans, and documents. The purposes of this document are to provide regional context for understanding water use in Beaver and Iron Counties and to describe water conservation strategies that can influence the trajectories of their future water use. 

In both Beaver and Iron Counties, agriculture remains the primary user of …