Life Sciences Commons^™

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

Cal Poly Humboldt theses and projects

MS-222 is a common fish anesthetic that dampens neural activity by inhibiting neuronal voltage-gated sodium channels (Na_v) 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 …

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

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

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

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

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, …

Knobcone Pine Response To Shading From Competing Chaparral Shrubs Following Stand-Replacing Wildfire, Sean T. Lindley

Cal Poly Humboldt theses and projects

In northern California, fire regimes are shifting towards more frequent and larger severe wildfire. There is growing concern that this shift poses a threat to biodiversity in the form of cover type change at the landscape scale, resulting in the extirpation of some species in favor of +AD617:AD649well-adapted ones. In northern California, mature serotinous conifers, such as knobcone pine (Pinus attenuata), and resprouting shrub species easily regenerate in severe patches of any size. There is no general consensus regarding the effects of shrub competition on conifer recruitment; conifer response varies with shade tolerance and other abiotic factors. Knobcone …

Physical Characteristics And Fine Roots Within Duff Mounds Of Old-Growth Sugar And Jeffrey Pine In A Fire-Excluded Sierran Mixed-Conifer Forest, Jules Bartley

Cal Poly Humboldt theses and projects

Fire exclusion has profoundly impacted frequent fire forests in western North America, disrupting fundamental ecological processes while leaving large, old pine trees vulnerable to drought, insects and disease, and fire. Forest managers want to increase the pace and scale of prescribed burning, yet heavy accumulations of organic material (duff mounds) at the bases of large pines can smolder for prolonged periods, damaging the cambium or consuming fine roots occupying the O horizon and/or upper mineral soil horizons. Increased duff mound depth is associated with greater mortality risk during prescribed fire, yet the biotic and abiotic drivers of duff mound accumulation …

Carnivore And Ungulate Occurrence In A Fire-Prone Region, Sara J. Moriarty-Graves

Cal Poly Humboldt theses and projects

Increasing fire size and severity in the western United States causes changes to ecosystems, species’ habitat use, and interspecific interactions. Wide-ranging carnivore and ungulate mammalian species and their interactions may be influenced by an increase in fire activity in northern California. Depending on the fire characteristics, ungulates may benefit from burned habitat due to an increase in forage availability, while carnivore species may be differentially impacted, but ultimately driven by bottom-up processes from a shift in prey availability. I used a three-step approach to estimate the single-species occupancy of four large mammal species: mountain lion (Puma concolor), coyote …

A Return To The Staging Grounds: Reassessment Of Aleutian Cackling Goose Spring Distribution In North Humboldt Bay, Shaun W. Thornton

Cal Poly Humboldt theses and projects

After a 15-year interval in research, spatial and temporal patterns of the Aleutian cackling goose during spring staging was assessed again in 2022. During my study, 3,389 goose flocks were recorded in Arcata Bottoms staging site, 1 January to 21 April 2022, amounting to an estimated total of 2,248,512 goosedays, which was 336.8% higher than 2007 estimates of 667,485 goosedays. Geese continued to use pastures with a wide range of landscape characteristics primarily represented by livestock grazing practices. Goose use was greater than availability on beef-cattle fields early in the season and dairy-cow fields later in the season. Human disturbances …

Will Climate Warming Amplify The Competitive And Predatory Effects Of A Range-Expanding Marine Gastropod (Acanthinucella Spirata)?, Bailey N. Mccann

Cal Poly Humboldt theses and projects

The effects of climate warming on the distribution of range-expanding species are well documented, but the interactive effects of climate warming and range-expanding species on recipient communities remain understudied. For example, with climate warming, range-expanding species may become a threat to local biodiversity due to their relatively stronger competitive or predatory effects on potentially weakened, or less well-adapted recipient communities. Acanthinucella spirata is a predatory marine gastropod that has expanded its distribution north along the California coast since the Pleistocene via a poleward geographical range shift, tracking climatic warming. To assess whether A. spirata has stronger predatory effects on the …

A Cladoxylopsid With Complex Vascular Architecture From The Early Devonian Battery Point Formation (Québec, Canada), Jessica Chu

Cal Poly Humboldt theses and projects

Cladoxylopsids are seed-free plants that formed the world’s earliest forests and gave rise to horsetails (sphenopsids), but their evolutionary origins are poorly understood. Here, I describe a new Early Devonian cladoxylopsid from the Emsian (400-395 Ma) Battery Point Formation (Québec, Canada). The structural features of this plant indicate taxonomic affinity to cladoxylalean cladoxylopsids and its phylogenetic position supports placement in genus Cladoxylon (the proposed name, Cladoxylon kespekianum sp. nov., to be formalized by peer-reviewed publication). Specimens of this plant are permineralized in calcium carbonate and were studied using the acetate peel technique with light and electron microscopy. Cladoxylon kespekianum is …

Assessing The Recovery Of Forest Understory Vegetation After Clearcut Logging Across A 445-Year Chronosequence, Molly Smith Metok

Cal Poly Humboldt theses and projects

The conversion of natural forested lands to managed forests has reduced the amount of older, structurally diverse forests worldwide. In conifer forests of the Pacific Northwest (USA) – where the understory plant communities comprise only 1% of forest biomass but represent 90% of the plant species richness – the long-term impacts of timber harvesting are not fully understood. I used a chronosequence of forests in southwestern Oregon that ranged from 25 to 445 years of age to compare changes in plant communities in logged (i.e., managed) stands with that of stands in late succession and old growth conditions. The chronosequence …

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 …

Genetic Evaluation Of The Current Distribution And Possible Diffrentations Between Lasiurus Borealis And Lasiurus Frantzii In Southwestern North America, Zeinab M. Haidar

Cal Poly Humboldt theses and projects

Several recent accounts of overlap and historic misidentifications regarding two species of the genus Lasiurus, Western red bat (Lasiurus frantzii) and Eastern red bat (Lasiurus borealis), have cast doubt on our understanding of their distribution, assumed spatial allopatry, and interactions in the United States Southwest. With the use of morphometrics and genetic sequencing, utilizing tissue collected from specimens throughout California and adjoining states, we have reassessed the current distribution, best practices for field identification, and genetic differentiation between both species. Appropriate species classification by region was achieved utilizing mitochondrial DNA, targeting the cytochrome c oxidase …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

Diversity And Distribution Of Bryozoans Of The Northern To Central Rocky Outer Coast Of California, Ismael Chowdhury

Cal Poly Humboldt theses and projects

The phylum Bryozoa is one of the most diverse groups of marine invertebrates, with a global distribution that spans marine and fresh waters. This study analyzes the Bryozoa in infralittoral communities on rocky surfaces from northern California (Point Saint George) to central California (Estero Bay), spanning 940 kilometers and encompassing 12 rocky intertidal sites. Although recent studies on bryozoan taxonomy and phylogeny have increased due to scanning electron microscopy (SEM) and high throughput sequencing, there is still a lack of studies on species found in shallow waters at intertidal depths, particularly in the northeastern Pacific. This study aims to expand …

Neural Crest Cell Migration And Developmental Origin Of Bony Scutes In White Sturgeon (Acipenser Transmontanus), Melody Tew

Cal Poly Humboldt theses and projects

Neural crest cells (NCCs) and mesodermal somites independently produce embryonic mesenchyme as a precursor to the chondrocytes and osteocytes of the vertebrate skeleton. In mammals and teleosts, NCCs only contribute to the dermal cranial skeleton, while the mesodermal somites and lateral plate mesoderm form the entire dermal and endochondral postcranial skeleton. In sharks, NCCs contribute to both the cranial and trunk integumentary skeleton. This suggests that contribution of the trunk neural crest mesenchyme to the integumentary skeleton was an ancestral condition for all vertebrates that was lost over evolutionary time in the osteichthyan lineage, but the evolutionary timing of this …

The Effect Of Brain Breaks On Student Academic Performance And Behaviors In The K-12 School Setting; A Meta-Analysis, Jesse Singh

Cal Poly Humboldt theses and projects

The purpose of this meta-analysis is to examine the effect of brain breaks on academic performance and in-class behaviors in the K-12 educational setting. Also, to conduct subgroup (moderator) analyzes to determine if Brain Breaks were more effective for specific (school and student) population characteristics. Standard meta-analytical procedures were used to determine inclusion criteria, article searches in electronic databases, coding procedures, and statistical methods to synthesize data. Moderator and outcome variables were assessed using coding procedures to understand if Brain Breaks were effective or not. The brain break interventions researched in this study have shown to produce variable results in …

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 …