Life Sciences Commons^™

The Effects Of Sex On Zebrafish Bone Metabolism, Simon Bagatto

Williams Honors College, Honors Research Projects

I investigated the effects of diet and sex on zebrafish bone metabolism. Zebrafish were subjected to either a high-calorie or low-calorie diet over a five-week period. After this diet, zebrafish scales were used to measure alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) enzyme activity with a fluorescent substrate. The enzyme activities were markers of the osteoblasts (ALP) and the osteoclasts (TRAP). These data were compared among sex and diet of the zebrafish using a repeated measures ANOVA statistical test. I also measured the number of resorption lacunae per scale (another indicator of osteoclast activity). The results showed higher TRAP …

Finding An Accurate Method To Measure Pollinator Visitation Rates, Claire Struhsaker

Williams Honors College, Honors Research Projects

Pollinator visitation rates are a helpful way to monitor the health of ecosystems; however, there lacks a standardized method for obtaining these rates. The pollinator visitation rates for five plant species were collected and the relationship between the standard error of these rates and the time interval was determined. Monarda, Echinacea purpurea, Pycnanthemum muticum, and Baptisia alba all exhibit more accurate pollinator visitation rates as the time interval increased. Trifolium repens exhibited less accurate pollinator visitation rates as the time interval increased.

Buoyancy And Emergence In Elymus Species, Sandor Jakab

Williams Honors College, Honors Research Projects

It is important that native plants are able to successfully emerge in wetlands because they play an important role in maintaining diversity. The relationship between seed buoyancy and seedling emergence was analyzed for three wetland species of the same genus: Elymus canadensis (FACU), Elymus macgregorii (FACW), and Elymus virginicus (FACW). E. macgregorii seemed to be the most buoyant, and E. virginicus and E. canadensis demonstrated very similar, less buoyant levels. Based on the idea that more buoyant seeds will be deposited at a shallow depth, and less buoyant seeds will be deposited at a deeper soil level, a relationship between …

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), …

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 …

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, …

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 …

Keep Working Hands On Working Land, Elyse Caiazzo

Graduate Student Portfolios, Professional Papers, and Capstone Projects

Strategies for Effective Farmland Transitions, Succession Planning, and Landowner Education

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, …

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 …

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 …

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 …

Investigating Tribal Co-Management Of Caifornia’S Public Lands, Zachary Joseph Erickson

Cal Poly Humboldt theses and projects

Collaborative management with Indigenous groups is becoming increasingly common as many Indigenous communities continue to assert their inherent rights to self-determination. Due to the removal from and dispossession of lands, tribes often rely on access to public properties for various uses including ceremonies and gathering of culturally important plants. Some believe that the absence of indigenous involvement has also led to a decline in both the quality and abundance of culturally important resources, as well as limited the intergenerational transfer of traditional ecological knowledge, or TEK. There is increasing momentum toward re-engaging tribes as stewards of their ancestral lands through …

Negative Social Media And Its Influence On Athlete's Performance, Bernd R. Huber

Cal Poly Humboldt theses and projects

This study aimed to investigate the potential impact of negative social media content on athletes' cortisol levels and subsequent performance. The study focused on the change in cortisol levels and differences in free throw performance, based on previous research findings. We hypothesized that negative social media postings would increase the stress experienced by student-athletes, resulting in elevated cortisol levels and decreased performance. Additionally, participants (n = 8) completed a questionnaire to examine the interaction between preexisting fear and the biological stress response. Contrary to expectations, there was no significant change in stress response, and negative postings did not have …

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 19^th and early 20^th 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 …

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 …

Rapidly Changing Range Limits In A Warming World: Critical Data Limitations And Knowledge Gaps For Advancing Understanding Of Mangrove Range Dynamics In The Southeastern Usa, Rémi Bardou, Michael J. Osland, Steven Scyphers, Christine Shepard, Karen E. Aerni, Jahson B. Alemu I, Robert Crimian, Richard H. Day, Nicholas M. Enwright, Laura C. Feher, Sarah L. Gibbs, Kiera O'Donnell, Savannah H. Swinea, Kalaina Thorne, Sarit Truskey, Anna R. Armitage, Ronald Baker, Josh L. Breithaupt, Kyle C. Cavanaugh, Erik S. Yando, A. Randall Hughes, Et Al.

Biological Sciences Faculty Publications

Climate change is altering species’ range limits and transforming ecosystems. For example, warming temperatures are leading to the range expansion of tropical, cold-sensitive species at the expense of their cold-tolerant counterparts. In some temperate and subtropical coastal wetlands, warming winters are enabling mangrove forest encroachment into salt marsh, which is a major regime shift that has significant ecological and societal ramifications. Here, we synthesized existing data and expert knowledge to assess the distribution of mangroves near rapidly changing range limits in the southeastern USA. We used expert elicitation to identify data limitations and highlight knowledge gaps for advancing understanding of …

Global Phylogenomic Assessment Of Leptoseris And Agaricia Reveals Substantial Undescibed Diversity At Mesophotic Depths, J. C. Gijsbers, N. Englebert, K. E. Prata, M. Pichon, Z. Dinesen, R. Brunner, G. Eyal, F. L. González-Zapata, S. E. Kahng, K. R. W. Latijnhouwers, P. Muir, V. Z. Radice, J. A. Sánchez, M. J. A. Vermeij, O. Hoegh-Guldberg, S. J. Jacobs, P. Bongaerts

Biological Sciences Faculty Publications

Background: Mesophotic coral communities are increasingly gaining attention for the unique biological diversity they host, exemplified by the numerous mesophotic fish species that continue to be discovered. In contrast, many of the photosynthetic scleractinian corals observed at mesophotic depths are assumed to be depth-generalists, with very few species characterised as mesophotic-specialists. This presumed lack of a specialised community remains largely untested, as phylogenetic studies on corals have rarely included mesophotic samples and have long suffered from resolution issues associated with traditional sequence markers.

Results: Here, we used reduced-representation genome sequencing to conduct a phylogenomic assessment of the two dominant mesophotic …

Corrigendum: Characterization Of A Novel Transitional Group Rickettsia Species (Rickettsia Tillamookensis Sp. Nov.) From The Western Black-Legged Tick, Ixodes Pacificus, David T. Gauthier, Sandor E. Karpathy, Stephanie L. Grizzard, Dhwani Batra, Lori A. Rowe, Christopher D. Paddock

Biological Sciences Faculty Publications

No abstract provided.

The Coral Bleaching Automated Stress System (Cbass): A Low Cost, Portable System For Standardized Empirical Assessments Of Coral Thermal Limits, Nicolas R. Evensen, Katherine E. Parker, Thomas A. Oliver, Stephen R. Palumbi, Cheryl A. Logan, James S. Ryan, Courtney N. Klepac, Gabriela Perna, Mark E. Warner, Christian R. Voolstra, Daniel J. Barshis

Biological Sciences Faculty Publications

Ocean warming is increasingly affecting marine ecosystems across the globe. Reef-building corals are particularly affected by warming, with mass bleaching events increasing in frequency and leading to widespread coral mortality. Yet, some corals can resist or recover from bleaching better than others. Such variability in thermal resilience could be critical to reef persistence; however, the scientific community lacks standardized diagnostic approaches to rapidly and comparatively assess coral thermal vulnerability prior to bleaching events. We present the Coral Bleaching Automated Stress System (CBASS) as a low-cost, open-source, field-portable experimental system for rapid empirical assessment of coral thermal thresholds using standardized temperature …

Territory Inheritance And The Evolution Of Cooperative Breeding In The Acorn Woodpecker, Walter D. Koenig, Joseph Haydock, Hannah L. Dugdale, Eric L. Walters

Biological Sciences Faculty Publications

There are two main hypotheses for why offspring in cooperatively breeding taxa delay dispersal and remain on their natal territory rather than disperse. First, ecological constraints may force offspring to remain on their natal territory until a reproductive opportunity presents itself in an otherwise saturated habitat. Alternatively, delaying dispersal and helping kin may increase an offspring's inclusive fitness. One means by which offspring might enhance their direct fitness by delaying dispersal is by inheriting breeding status on their natal territory. Such territory inheritance regularly occurs in acorn woodpeckers, Melanerpes formicivorus, a species whose social groups consist of a cooperatively …

Variation In Establishment Success For American Mistletoe [Phoradendron Leucarpum (Raf.) Reveal & M.C. Johnst. (Viscaceae)] Appears Most Likely To Predict Its Distribution In Virginia And North Carolina, United States, Nicholas P. Flanders, Christopher P. Randle, Eric L. Walters, Lytton J. Musselman

Biological Sciences Faculty Publications

Dispersal limitation and variation in habitat suitability may determine an association of American mistletoe [Phoradendron leucarpum (Raf.) Reveal & M.C. Johnst. (Viscaceae)] with forested wetlands in Virginia and North Carolina, United States. Here, we first tested the alternative hypothesis that variation in host availability drives this habitat relationship. We used a generalized linear model to show a positive effect of forested wetland habitat on American mistletoe occurrence after accounting for both variation in host availability and differences among regions in host use. We then used seed sowing experiments to quantify how light availability and flood regime determine the viability …

Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace

Biological Sciences Faculty Publications

Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of …

Co-Occurrence Of Marine And Freshwater Phycotoxins In Oysters, And Analysis Of Possible Predictors For Management, Sarah K. D. Pease, Todd A. Egerton, Kimberly S. Reece, Marta P. Sanderson, Michelle D. Onofrio, Evan Yeargan, Adam Wood, Amanda Roach, I-Shuo Wade Huang, Gail P. Scott, Allen R. Place, Amy M. Hayes, Juliette L. Smith

Biological Sciences Faculty Publications

Oysters (Crassostrea virginica) were screened for 12 phycotoxins over two years in nearshore waters to collect baseline phycotoxin data and to determine prevalence of phycotoxin co-occurrence in the commercially and ecologically-relevant species. Trace to low concentrations of azaspiracid-1 and -2 (AZA1, AZA2), domoic acid (DA), okadaic acid (OA), and dinophysistoxin-1 (DTX1) were detected, orders of magnitude below seafood safety action levels. Microcystins (MCs), MC-RR and MC-YR, were also found in oysters (maximum: 7.12 μg MC-RR/kg shellfish meat wet weight), warranting consideration of developing action levels for freshwater phycotoxins in marine shellfish. Oysters contained phycotoxins that impair shellfish health: karlotoxin1-1 and …

Mechanical Devices For Census And Detection Of Off-Host Larval Ticks (Acari: Ixodidae), Donald B. Thomas, Holly D. Gaff, Brenda Leal-Galvan

Biological Sciences Faculty Publications

Standard off-host tick census techniques are generally inefficient for larval stages. Also, such techniques expose the investigator to environmental hazards including tick bites. Mechanical devices are an option which were tested under field conditions for proof of concept and in side-by-side comparison to the standard techniques. The tick-vac collected more ticks than the legging technique, but with lower frequency of positive detections. It may have utility for sampling small areas, such as weedy corrals suspected of harboring ticks. Different configurations of tick-bots, robotic vehicles with flags, depended on intensive operator control to avoid obstacles, limiting operation to line of sight. …

Blue Carbon Science, Management And Policy Across A Tropical Urban Landscape, Daniel A. Friess, Yasmine M. Gatt, Tze Kwan Fung, Jahson B. Alemu I, Natasha Bhatia, Rebecca Case, Siew Chin Chua, Danwei Huang, Valerie Kwan, Kiah Eng Lim, Yudhishthra Nathan, Yan Xiang Ow, Daniel Saavedra-Hortua, Taylor M. Sloey, Erik S. Yando, Hassan Ibrahim, Lian Pin Koh, Jun Yu Puah, Serena Lay-Ming Teo, Karenne Tun, Lynn Wei Wong, Siti Maryam Yaakub

Biological Sciences Faculty Publications

The ability of vegetated coastal ecosystems to sequester high rates of “blue” carbon over millennial time scales has attracted the interest of national and international policy makers as a tool for climate change mitigation. Whereas focus on blue carbon conservation has been mostly on threatened rural seascapes, there is scope to consider blue carbon dynamics along highly fragmented and developed urban coastlines. The tropical city state of Singapore is used as a case study of urban blue carbon knowledge generation, how blue carbon changes over time with urban development, and how such knowledge can be integrated into urban planning alongside …

A Multi-Isotope Approach Reveals Seasonal Variation In The Reliance On Marine Resources, Production Of Metabolic Water, And Ingestion Of Seawater By Two Species Of Coastal Passerine To Maintain Water Balance, Lucas Navarrete, Nico Lübcker, Felipe Alvarez, Roberto Nespolo, Juan Carlos Sanchez-Hernandez, Karin Maldonado, Zachary D. Sharp, John P. Whiteman, Seth D. Newsome, Pablo Sabat

Biological Sciences Faculty Publications

Tracing how free-ranging organisms interact with their environment to maintain water balance is a difficult topic to study for logistical and methodological reasons. We use a novel combination of triple-oxygen stable isotope analyses of water extracted from plasma (δ¹⁶O, δ¹⁷O, δ¹⁸O) and bulk tissue carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes of feathers and blood to estimate the proportional contribution of marine resources, seawater, and metabolic water used by two species of unique songbirds (genus Cinclodes) to maintain their water balance in a seasonal coastal environment. We …

The Practice And Promise Of Temporal Genomics For Measuring Evolutionary Responses To Global Change, René D. Clark, Katrina A. Catalano, Kyra S. Fitz, Eric Garcia, Kyle E. Jaynes, Brendan N. Reid, Allyson Sawkins, Anthony A. Snead, John C. Whalen, Malin L. Pinsky

Biological Sciences Faculty Publications

Understanding the evolutionary consequences of anthropogenic change is imperative for estimating long-term species resilience. While contemporary genomic data can provide us with important insights into recent demographic histories, investigating past change using present genomic data alone has limitations. In comparison, temporal genomics studies, defined herein as those that incorporate time series genomic data, utilize museum collections and repeated field sampling to directly examine evolutionary change. As temporal genomics is applied to more systems, species and questions, best practices can be helpful guides to make the most efficient use of limited resources. Here, we conduct a systematic literature review to synthesize …