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Full-Text Articles in Life Sciences

Effect Of In Situ Experimental Heating Of Artificial Mytilus Californianus Beds On Associated Invertebrate Communities In Northern California, Claire C. Windecker Jan 2023

Effect Of In Situ Experimental Heating Of Artificial Mytilus Californianus Beds On Associated Invertebrate Communities In Northern California, Claire C. Windecker

Cal Poly Humboldt theses and projects

With the continued progression of climate change, the role of foundation species as mediators of temperature stress for species living on and within them has become increasingly important. In the intertidal zone, a major foundation species is the California mussel, Mytilus californianus, which can help to limit thermal stress for species that live among aggregations of these mussels. The ability of mussels to limit thermal stress as temperatures increase, however, is still unclear. This study sought to experimentally manipulate surface temperatures of artificial mussel beds in situ to examine the effects that increased surface heating at a single site …


Using Multiscale Ensemble Habitat Models To Identify Wildfire Risk To Habitat For An Iconic Forest Species, Logan Baker Hysen Jan 2023

Using Multiscale Ensemble Habitat Models To Identify Wildfire Risk To Habitat For An Iconic Forest Species, Logan Baker Hysen

Cal Poly Humboldt theses and projects

Large and severe wildfires, exacerbated by climate change and human behavior, are occurring more frequently in many forests across the western United States. While wildfire is a natural part of most terrestrial ecosystems, rapidly changing fire regimes have the potential to alter habitat beyond the adaptive capabilities of species. Spatial assessments of wildfire risks to species habitat may allow managers to pinpoint locations for management activities. To illustrate this, I spatially assessed wildfire risk within habitat that supports the nesting activity of the federally threatened northern spotted owl (Strix occidentalis caurina) in the California redwood coast ecoregion. To …


Olfactory Organ Morphology And Ultrastructure Of The Larval Koh Tao Island Caecilian (Ichthyophis Kohtaoensis), Jaclyn M. Patmore Jan 2023

Olfactory Organ Morphology And Ultrastructure Of The Larval Koh Tao Island Caecilian (Ichthyophis Kohtaoensis), Jaclyn M. Patmore

Cal Poly Humboldt theses and projects

The olfactory system of living amphibians (Lissamphibia) undergoes major changes as it transitions from an aquatic to a terrestrial system during metamorphosis. Patterns of change in the cellular morphology of the nose have been examined for frogs (Anura) and salamanders (Caudata). However, it remains unknown if caecilians (Gymnophiona) have similar patterns of change in their nasal ultrastructure. In particular, no data on larval caecilian olfactory cell types are available. Here, using light microscopy and transmission electron microscopy, I examined the olfactory organ of larvae of the caecilian Ichthyophis kohtaoensis, to establish the ultrastructure of the epithelium and compare it …


The Benefits Of Physical Education Programs For Students In Special Education Programs With Attention Deficit Hyperactivity Disorder, Deborah A. Mok Jan 2023

The Benefits Of Physical Education Programs For Students In Special Education Programs With Attention Deficit Hyperactivity Disorder, Deborah A. Mok

Cal Poly Humboldt theses and projects

Researchers have reported that exercise has had positive results on decreasing many behaviors for children with ADHD. The purpose of this study is to examine the impact of a structured physical education program for students in grades K-4 with attention deficit hyperactivity disorder (ADHD) on academic performance. This study utilized a single subject withdrawal design. Four participants attending a special day class in grades K-4 in Northern California participated in this study. Results of this study demonstrated that 30 minutes of structured physical activity had a positive impact on decreasing the number of off-task behaviors for all four of the …


Effects Of Oyster Aquaculture On Elasmobranch Abundance And Habitat Use In Humboldt Bay, Ca, Rose Harman Jan 2023

Effects Of Oyster Aquaculture On Elasmobranch Abundance And Habitat Use In Humboldt Bay, Ca, Rose Harman

Cal Poly Humboldt theses and projects

Habitat modification from aquaculture can have large effects on natural communities, with the habitat complexity provided by aquaculture structure positively influencing benthic invertebrates and small fish abundance. However, the effects of aquaculture on larger predatory fish like elasmobranchs (i.e., sharks and rays), which use nearshore habitat to forage and provide top-down control of these ecosystems, is largely unknown. Over two years, I deployed baited remote underwater video systems (BRUVS) to examine the effects of oyster aquaculture and environmental variables such as habitat (mudflat or eelgrass), salinity (ppt), turbidity (m), temperature (°C), pH (mV), dissolved oxygen (mg · L-1), …


Prevalence Of Batrachochytrium And Ranavirus In Southern Torrent Salamanders (Rhyacotriton Variegatus) In Northern California, Marilyn Violeta Sandoval Jan 2023

Prevalence Of Batrachochytrium And Ranavirus In Southern Torrent Salamanders (Rhyacotriton Variegatus) In Northern California, Marilyn Violeta Sandoval

Cal Poly Humboldt theses and projects

Amphibian population declines around the world have been attributed in part to the emergence of deadly pathogens. However, the severity of the effects of pathogens on amphibian communities can vary by species and location. This study focuses on assessing the prevalence of Batrachochytrium dendrobatidis (Bd), Batrachochytrium salamandrivorans (Bsal), and ranaviruses in populations of southern torrent salamanders (Rhyacotriton variegatus). I also tested for association between environmental factors and the prevalence and viral load of the three pathogens in Northern California. A total of 309 skin swab samples were collected from salamanders in nine sites in …


Western Gulls’ (Larus Occidentalis) Reproductive And Behavioral Responses To Human Disturbance, Lilamarie 'Asta Bowen Jan 2023

Western Gulls’ (Larus Occidentalis) Reproductive And Behavioral Responses To Human Disturbance, Lilamarie 'Asta Bowen

Cal Poly Humboldt theses and projects

Human disturbances can negatively affect wildlife by causing stress, altering behavior, or even impacting populations through changes in survival or productivity. Colonial-nesting seabirds are of particular concern due to population declines and their gregarious and conspicuous nature, which may attract human visitors. However, the effects of nearby human activities, though frequently negative, could be neutral or even positive through phenomena like habituation to human activities or subsidization by human-supplied food sources. In this observational study, I evaluated relative support for three hypotheses which may explain how Western Gulls are impacted by human activity: disturbance, habituation, and subsidization. I investigated this …


Effects Of Exergaming On Health And Fitness Outcomes For Students With Disabilities: A Meta-Analysis, Jason Abaya Jan 2023

Effects Of Exergaming On Health And Fitness Outcomes For Students With Disabilities: A Meta-Analysis, Jason Abaya

Cal Poly Humboldt theses and projects

Background: The high prevalence of obesity in America can be attributed to the lack of resources and physical activity for students with disabilities. This meta-analysis presents how current literature on exergaming affects the Health Related Fitness, Skill Related Fitness, and Motor Skills of students with a diagnosed disability.

Method: The search strategy for this meta-analysis was to identify previous studies using specific keywords (e.g., Exergaming, Wii-Fit, VR, Physical Education, Adapted Physical Education). Studies were included and sorted based on inclusion and exclusion criteria.

Results: Based on 20 studies that met the inclusion criteria, there were increased fitness outs, however not …


Comparing Mexican Spotted Owl Habitat Suitability In Two Different Habitat Types Using A Multi-Scale Ensemble Learning Framework, Danial Nayeri Jan 2023

Comparing Mexican Spotted Owl Habitat Suitability In Two Different Habitat Types Using A Multi-Scale Ensemble Learning Framework, Danial Nayeri

Cal Poly Humboldt theses and projects

Habitat fragmentation and loss are major threats to species conservation worldwide. Studying species-habitat relationships is a crucial first step toward understanding species habitat requirements, which is necessary for conservation and management planning. However, some species inhabit a range of habitat types, potentially making the use of range-wide habitat models inappropriate due to non-stationarity. The Mexican spotted owl (Strix occidentalis lucida) (MSO) is a species that inhabits both forests and rocky canyonlands, two habitats with large differences in environmental conditions. It is unclear whether the species uses habitat differently in these two habitat types or if previously builthabitat models …


Survival And Growth Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Restored Wetlands Of Humboldt Bay, California, Josh D. Cahill Jan 2023

Survival And Growth Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Restored Wetlands Of Humboldt Bay, California, Josh D. Cahill

Cal Poly Humboldt theses and projects

Substantial investment in habitat restoration efforts have been made to promote coho salmon (Oncorhynchus kisutch) recovery, yet sampling efforts to document the response of coho salmon populations to wetland restoration are limited. I investigated two cohorts of juvenile coho salmon growth, movement, and survival within the Humboldt Bay drainage in California. My study sites included restoration features and other sample areas in upland creek habitat and in lowland estuarine wetlands that were located in the four largest watersheds within the Humboldt Bay drainage. The objectives of this study were to: (1) determine if coho salmon are using restored, …


The Interaction Of Treadmill Type And Incline Slope On Biomechanics And Muscle Activation During Human Locomotion, Rohit Kundu Jan 2023

The Interaction Of Treadmill Type And Incline Slope On Biomechanics And Muscle Activation During Human Locomotion, Rohit Kundu

Cal Poly Humboldt theses and projects

Treadmills are widely used in biomechanical research. However, variations in treadmill design and running surfaces may affect biomechanical variables such as muscle activation and impact acceleration. In addition, incline walking on treadmills leads to changes in the pattern of muscle activation, particularly at steeper inclines. Despite extensive research on the effects of running surfaces and inclines on biomechanical variables (gait, muscle activation, impact force), the impact of varying treadmill manufacturers on biomechanical variables at high inclines remains unclear. Purpose: To determine whether the type of treadmill deck influences surface electromyography (EMG) patterns and impact accelerations at high incline (20%) walking …


Community Ecology And Disease Dynamics In Pacific Oysters: Unraveling Microbiome-Pathogen Interactions In The Wild, Victoria E. Cifelli Jan 2023

Community Ecology And Disease Dynamics In Pacific Oysters: Unraveling Microbiome-Pathogen Interactions In The Wild, Victoria E. Cifelli

Cal Poly Humboldt theses and projects

In the context of multispecies microbial assemblages, disruptions can occur when there are alterations in host conditions, such as the onset of a disease. Notably, viruses have the potential to reshape a host's microbial community. However, the role of the host's habitat and environment, which could be pivotal in communities with shifting niche space and habitat filters, is often overlooked in host-microbe-pathogen interactions. Recognizing the importance of these factors, I employed a field-based approach to understand microbial community dynamics in the presence of disease. To address the influence of geographical location, I conducted an analysis involving healthy and infected oysters …


Polymorphism Of Melanin-Based Pigments In Barn Owls In Winegrape Vineyards In Napa Valley, California, Laura Mariana Echávez Montenegro Jan 2023

Polymorphism Of Melanin-Based Pigments In Barn Owls In Winegrape Vineyards In Napa Valley, California, Laura Mariana Echávez Montenegro

Cal Poly Humboldt theses and projects

Many raptor species exhibit plumage polymorphism. Through the expression of a particular phenotype, polymorphism allows individuals to exploit alternative spatial or temporal environments and food resources most successfully. Barn Owls display within-species variation in their plumage, ranging from reddish to whitish and from heavily spotted to having no spots at all. In heterogeneous landscapes in Europe and the Middle East, reddish Common Barn Owls (Tyto alba) inhabit territories with proportionally more arable fields and consume proportionally more voles than mice in contrast to their whiter counterparts; a phenomenon known as habitat matching choice. This study sought to quantify …


Macrolichen Inventory Of The Horse Mountain Botanical Area, Six Rivers National Forest, California, Usa, Sarah Norvell Conway Jan 2023

Macrolichen Inventory Of The Horse Mountain Botanical Area, Six Rivers National Forest, California, Usa, Sarah Norvell Conway

Cal Poly Humboldt theses and projects

Macrolichen diversity and community composition was determined for an area of high botanical interest in the Coast Ranges of Northern California – the Horse Mountain Botanical Area (HMBA) in Six Rivers National Forest. The Coast Ranges have been suggested to have high epiphytic macrolichen diversity, yet detailed site-specific macrolichen surveys are lacking for the area. Here we present comprehensive data on macrolichens of the HMBA integrated with environmental metadata at the landscape level. Twenty 0.4 ha sampling plots were positioned across the varying habitats of the HMBA and macrolichens were intensively sampled from all substrata. Out of 888 total collections, …


Sympatric Carnivores And Vegetation Structure Influence The Distribution And Abundance Of Humboldt Martens In Northern California, Erika L. Anderson Jan 2023

Sympatric Carnivores And Vegetation Structure Influence The Distribution And Abundance Of Humboldt Martens In Northern California, Erika L. Anderson

Cal Poly Humboldt theses and projects

The Humboldt marten (Martes caurina humboldtensis) is a species facing conservation concern in Oregon and California. Historical populations were subjected to unregulated fur trapping and timber harvest throughout the late 19th and early 20th centuries leading to a 90% decline in their distribution. As such, the Humboldt marten is listed as a state endangered species in California, and the analogous ‘coastal marten’ is listed as federally threatened under the Endangered Species Act and classified as a Species of Greatest Conservation Need in Oregon and California. Contemporary populations are small, and isolated, and threatened by habitat loss …


Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty Jan 2023

Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty

Cal Poly Humboldt theses and projects

The Scott River supports the most robust population of threatened Coho Salmon Oncorhynchus kisutch remaining in the Klamath River basin. Even in the Scott River, low quality and restricted extent of juvenile rearing habitat limits the Coho Salmon population to a small fraction of historic abundance. To support persistence and recovery of Scott River Coho Salmon, the Scott River Watershed Council (SRWC) has constructed a portfolio of restoration projects to improve juvenile rearing habitat, including beaver dam analogs (BDAs). The Scott River BDAs were the first implemented anywhere in California. This study compares juvenile Coho Salmon responses associated with production …


A Picture Worth A Thousand Words: Factors Influencing Disability Accommodations, Alicia E. Martin Jan 2023

A Picture Worth A Thousand Words: Factors Influencing Disability Accommodations, Alicia E. Martin

Cal Poly Humboldt theses and projects

Because not all disabilities look the same it is difficult to label a person with disabilities just by looking at them. Given that our knowledge, attitudes, and perceptions impact how we interpret our world and our willingness to act, people, including professors, may be biased toward providing accommodations for those with easily recognizable disabilities and biased against those with non-recognizable disabilities, and this may impact the disabled person’s ability to learn. This thesis aims to address whether professors’ disability-related attitudes, perceptions of accommodation reasonableness, and willingness to provide accommodations differ when the disability is recognizable (student is pictured in a …


Insights Into The Conservation Of The Rare Perennial Herb, Astragalus Applegatei, Sean Stewart Jan 2023

Insights Into The Conservation Of The Rare Perennial Herb, Astragalus Applegatei, Sean Stewart

Cal Poly Humboldt theses and projects

As anthropogenic activities expand, conservation of rare and endangered species is critical to reduce extinction risks. Collecting and analyzing demographic data can assist in the development of conservation strategies and can help evaluate the success of existing strategies. In this study, I built integral projection models from five years of demographic data and conducted a population viability analysis on four populations of the rare perennial herb, Astragalus applegatei, to inform conservation decisions. I also assessed how planting A. applegatei seedlings might contribute to the growth of an extant population. I found that one population was already below the extinction …


Use Of Foreign Edna Tracers To Resolve Site- And Time-Specific Edna Distributions In Natural Streams, Braden A. Herman Jan 2023

Use Of Foreign Edna Tracers To Resolve Site- And Time-Specific Edna Distributions In Natural Streams, Braden A. Herman

Cal Poly Humboldt theses and projects

Substantial uncertainty in how to interpret eDNA observations motivates a need for a technique to effectively and efficiently measure of system- and time-specific eDNA distributions. Using a technique to robustly calibrate eDNA dynamics in a given system would improve established eDNA methods such as presence and absence and has the potential to refine estimates of organism abundance using eDNA concentration that are less well understood. Particles of eDNA are present in a wide variety of size and type resulting in varying transport dynamics, persistence, decay, among others. This variation likely makes eDNA transport more complex than that of conservative tracers …


Is The Area Postrema Resistant To The Anesthetic Effects Of Ms-222?, Austin T. Csiszar Jan 2023

Is The Area Postrema Resistant To The Anesthetic Effects Of Ms-222?, Austin T. Csiszar

Cal Poly Humboldt theses and projects

MS-222 is a common fish anesthetic that dampens neural activity by inhibiting neuronal voltage-gated sodium channels (Nav) required for action potentials. Previous experiments conducted by our lab’s primary investigator using fluorescence calcium imaging in zebrafish neurons resulted in the observation that neurons in the area postrema (AP), a circumventricular organ located in the dorsal hindbrain, displayed prominent fluorescence intensity during MS-222 induced sedation. I used the genetically encoded calcium indicator GCaMP6s to conduct fluorescence calcium imaging with the goal of recording neural activity in the larval zebrafish area postrema and optic tectum to compare the anesthetic effects of …


Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund Jan 2023

Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund

Cal Poly Humboldt theses and projects

Non-native species are increasing in prevalence around the world, resulting in negative economic and ecological impacts. However, the broad distributions of non-native species also offer a system for investigating the response of host-associated microbial communities to environmental factors across a range of ecological scales. At the broadest scale, I investigated the geography of microbial communities in the non-native estuarine anemone Diadumene lineata on the west coast of the United States of America. Across latitudes, microbial community composition was very similar and displayed a high percentage of Klebsiella spp. at all sites. However, the communities in California tended to exhibit higher …


Effects Of Ph, Eelgrass, And Settlement Substrate On The Growth Of Juvenile Magallana (Crassostrea) Gigas, A Commercially Important Oyster Species, Johnny S. Roche Jan 2023

Effects Of Ph, Eelgrass, And Settlement Substrate On The Growth Of Juvenile Magallana (Crassostrea) Gigas, A Commercially Important Oyster Species, Johnny S. Roche

Cal Poly Humboldt theses and projects

Worsening ocean acidification (OA), resulting from ongoing absorption of atmospheric carbon dioxide (CO2) by the oceans, threatens marine life globally. Calcifying organisms, especially their early life stages, are particularly vulnerable; this includes the economically important Pacific oyster, Magallana (Crassostrea) gigas. Uptake of dissolved CO2 through photosynthesis by seagrasses, like eelgrass (Zostera marina), may benefit calcifying organisms by increasing pH and carbonate availability. I conducted laboratory and field experiments to quantify carbonate chemistry modification by eelgrass and potential mitigation of OA impacts on growth in juvenile Pacific oysters. In the laboratory experiment, daytime …


Establishing A Market Capacity And Economic Baseline For Forest Biomass Utilization In The Southern Cascade And Northern Sierra Nevada Mountain Range, California, Clarke Stevenson Jan 2023

Establishing A Market Capacity And Economic Baseline For Forest Biomass Utilization In The Southern Cascade And Northern Sierra Nevada Mountain Range, California, Clarke Stevenson

Cal Poly Humboldt theses and projects

Attempts to address wildfire risk and forest resilience have increased substantially over the last 20 years with specific interest in removing excess vegetation from stands, commonly referred to as “forest biomass”. However, the market capacity for and the economics of biomass utilization have been a limiting factor to achieving statewide goals for forest health and fire resilience. This thesis looks at the Southern Cascade and Northern Sierra Nevada biomass supply chain to benchmark current market capacity for biomass utilization through mapping and harvest record analysis. It also calculates the net revenue of biomass mobilization based on costs developed from a …


Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott Jan 2023

Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott

Cal Poly Humboldt theses and projects

Harmful algal blooms (HABs) result from outbreaks of any of several different species of toxin-producing phytoplankton and that can have major detrimental effects on marine ecosystems and pose severe health and economic threats to human communities. Of particular concern along the United States West Coast are HABs of pennate diatom genus Pseudo-nitzschia that produce the potent neurotoxin domoic acid (DA). The coastal ocean between Cape Mendocino, CA, and Cape Blanco, OR is a hotspot for Pseudo-nitzschia spp. HABs. Such blooms impact coastal fisheries and pose a potential threat to aquaculture operations in Humboldt Bay, California’s second largest estuary and largest …


Long-Line Culture Of Red Seaweed In The Pacific Northwest, Erika R. Thalman Jan 2023

Long-Line Culture Of Red Seaweed In The Pacific Northwest, Erika R. Thalman

Cal Poly Humboldt theses and projects

The goal of this study was to adapt open-water rope culture techniques to the native red seaweed Devaleraea mollis to support a new seaweed aquaculture industry in Humboldt Bay, California. The specific objectives for this study were to: 1) evaluate the growth of D. mollis cultivated at different depths and seasons (fall/winter, spring/summer), 2) estimate nutrients removed by D. mollis from the water, and 3) measure heavy metals and pesticides to determine potential health risk upon ingestion. Bundles of seaweed were inserted into 3 m long weighted vertical lines attached to two horizontal long-lines suspended by floats. Two four-month …


The Relationship Between Gluteus Maximus Activation And Running Kinematics In Recreational Distance Runners, Ricardo Sanchez Jan 2023

The Relationship Between Gluteus Maximus Activation And Running Kinematics In Recreational Distance Runners, Ricardo Sanchez

Cal Poly Humboldt theses and projects

Within the running community, there are strategies that a trainer will utilize to improve the performance of an athlete. One of these strategies suggests that an increase in activation of the Gluteus Maximus (GM) muscle will result in an increase in the efficiency of runners. The primary purpose of this study was to examine the relationship between GM activation and running kinematics.

Methods: Three female and seven male recreational runners (27±8 yrs) from California Polytechnic State University, Humboldt and the local community. A Pearson product-correlation was used to determine the strength of the relationship between Gluteus Maximus activation and kinematic …


Effects Of Depth, Distance To Shore, And Water Velocity On Organismal And Extra-Organismal Environmental Dna Concentrations In A Large River, Dylan Keel Jan 2023

Effects Of Depth, Distance To Shore, And Water Velocity On Organismal And Extra-Organismal Environmental Dna Concentrations In A Large River, Dylan Keel

Cal Poly Humboldt theses and projects

Environmental DNA (eDNA) is a sensitive tool for detection of aquatic species and concentrations of eDNA in water samples have been useful for estimating abundance. This study evaluated the effects of depth, distance to shore, and water velocity on the concentration of organismal and extra-organismal eDNA concentrations in the Klamath River, California (basin area ≅ 40,000 km2). At each of six river cross sections 32 water samples were collected, including surface samples and depth samples evenly distributed across the cross section, and eDNA concentrations were determined for the parasite Ceratonova shasta and Chinook salmon, Oncorhynchus tshawytscha, using …


The Effects Of Aquatic Programs On Students With Disabilities Fitness And Skill-Based Outcomes; A Meta-Analysis, Delaney Hughes Jan 2023

The Effects Of Aquatic Programs On Students With Disabilities Fitness And Skill-Based Outcomes; A Meta-Analysis, Delaney Hughes

Cal Poly Humboldt theses and projects

The purpose of the meta-analysis was to determine the impact of aquatic-based interventions on health-related fitness and skill-based outcomes for children with disabilities. PRISMA guidelines were used to complete the procedures of the meta-analysis. Twenty-three studies met the inclusion criteria and results indicate that overall, aquatic programming likely positively affects students with disabilities and health-related fitness outcomes. Recommendations provide direction for future studies to help improve intervention results.


Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder Jan 2023

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al3+ on plants and microbes by binding with Al3+, thus preventing Al3+ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …


Investigating The Effectiveness Of Microplastic Removal And The Relationship Between Microplastics, Bacterial Communities, And Nitrogen Cycling In The Natural Treatment Systems At The Arcata Wastewater Treatment Facility, Fiona Connor Jan 2023

Investigating The Effectiveness Of Microplastic Removal And The Relationship Between Microplastics, Bacterial Communities, And Nitrogen Cycling In The Natural Treatment Systems At The Arcata Wastewater Treatment Facility, Fiona Connor

Cal Poly Humboldt theses and projects

This thesis addressed two challenging aspects of microplastic research, including the quantification of microplastics in organic-rich water, and the investigation of how microplastics impact microorganisms and related nutrient-cycling. Two projects were designed and executed to address specific research objectives relating to these broad topics. The first objective was to develop and implement methods to determine the effectiveness of microplastic removal across the natural treatment systems at the Arcata Wastewater Treatment Facility (AWTF). The second objective was to observe how microplastics found in domestic wastewater impact the bacterial communities and nitrogen cycling in freshwater treatment wetland sediment through a bench-scale experiment, …